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7 - Update on the Source Water Master PlanCITYOFBOULDER WATER RESOURCES ADVISORY BOARD AGENDAITEM MEETING DATE: August 20, 2007 AGENDA TITLE: Update on the Source Water Master Plan PRESENTER/S: Bob Harberg, Utilities Project Mauagement Coordinator Carol Ellinghouse, Water Resources Coordiaator Joe Taddeucci, Utilities Project Manager EXECUTIVE SUMMARY: The 1988 Raw Water Master Plan (RWMP) focused on the evaluation of the adequacy of the city's water supplies and options for use of the water owned by the city. One of the key outcomes of the RWMP was adoption of reliability criteria by the Ciry Council for the city's raw water supplies. These criteria specified the acceptable level and frequency of water use restrictions in Boulder. City Council's policy was based on recognition that it was economically impractical to supply water for all uses at all times given Boulder's semi-arid climate. Following this first step toward long-term drought planning, the city took additional steps of setting reliability criteria for the treated water supply system, instituting an on-going water conservation program and preparing a drought response plan. The Source Water Master Plan (SWMP) will build on the previous RWMP and will focus on the following objectives: • Compile descriptive and background information for the assets and resources which comprise the city's source water system; • Review and update water use statistics and water rights yields; • Document policies which affect source water system development, use and management; • Define current and emerging issues pertaining to the city's source water assets, facilities and resources; • Review current operations and maintenance practices; • Develop recommendations for future studies and improvements, and; • Provide general budgeting information and project prioritization to guide development of the ten-year Capital Improvements Program. The SWMP is being prepared by staff with assistance from MWH, a Denver based water resources engineering firm whose primary role will be facilities condition assessment and development of costs for and prioritization of recommended studies and improvements. The master planning effort will include involvement of a community focus group led by a AGENDA ITEM # PAGE professional facilitator. In addition, city staff representing various city interests wil] be surveyed to gather opinions concerning key source water issues facing the city both now and in the future. This presentation was developed to introduce WRAB to the envisioned SWMP and obtain comments conceming plan scope and contents. Staff anticipates updating WRAB concerning plan progress in November 2007, presenting the draft SWMP to WRAB in January 2008, and retuming to WRAB in March 2008 for a recommendation conceming adoption of the plan. Prior to presenting the draft SWMP to WRAB, staff will solicit feedback during a quarterly master planning review meeting. Fiscal Impacts: Budgetary: Funding sufficient to complete the master plan is available in the Utilities Division budget. Staff Time: Staff has taken the responsibility for developing background information to reduce consultant costs. Project staff time is a part of the normal work plan. Other Impacts: Environmental: None directly attributable to the planning effort. Economic: Recommendations presented in the final SWMP will be considered in developing the Capital Improvement Program for the next several years. Community: Staff is currently identifying potential members for a focus group to incorporate public input as the project progresses. Other Board and Commission feedback and public feedback: The current project schedule includes: • September 2007- January 2008 - Four community focus group meetings • April 2008 - Presentation of the final SWMP to Planning Board • May 2008 - City Council consideration of the SWMP. Staff recommendation: Staff requests WRAB comments on the scope and focus of the SWMP, as well as any specific concems and issues that should be addressed in the master plan. Suggestions conceming focus group membership would also be appreciated. Analysis: One of the city of Boulder's most important assets is its water supplies. Boulder's founders recognized the importance of a reliable water supply and began developing a water supply system for the growing city in the late 1800's. Subsequent generations have expanded and maintained the water system and planned for its future. Current citizens of Boulder are the beneficiaries of these forward-thinking individuals and their efforts in the past. Thoughtful planning for the city's future water needs at this time can help assure that future Boulder citizens also inherit a reliable and sufficient water supply. In 1987, the ciry initiated a public review process to evaluate the water supplies that Boulder owned and discuss options for use of the water. The studies resulted in the 1988 Raw Water Master Plan (RWMP). The focus of the RWMP was mostly on water yield AGENDA ITEM # PAGE and uses in the city and less on raw water system infrastructure. Several of the recommendations in the RWMP were adopted for further acrion by the City Council. One of the key outcomes of the RWMP was adoption of reliability criteria by the City Council for the city's raw water supplies. These criteria are that the city should maintain control over water supplies sufficient to meet the forecasted build-out water demands of the Boulder Valley with three levels of specified reliability: Water needed for essential uses should be asswed agaist droughts with 1000-year recurrence intervals or less. 2. Water needed to sustain landscaping should be assured against drought with 100- year recurrence intervals or less. 3. Water sufficient to meet total demand should be asswed against droughts with 20- year recurrence intervals or less. In addition, city policy at the time was to preserve its options for future acquisition and disposal of water supplies in response to changes in future demands. These criteria specified the acceptable level and frequency of water use restrictions in " Boulder due to drought. City CounciPs policy was based on a recognition that it was economically impractical to supply water for all uses at all times given Boulder's semi- arid climate. Following this fust step towazd long-term drought planning, the city took addirional steps of setting reliability criteria for the treated water supply system, instituting an on-going water conservarion program, and preparing a drought response plan. One of the findings of the RWMP was that Boulder owned sufficient water supplies to meet projected municipal demands at build-out. Although Ciry Counci] did not recommend a permanent reduction in the yield of the ciTy's water portfolio through sale of water, they did recognize that the Windy Gap water was the city's most expensive and least reliable water. Council recommended that staff attempt to reconfigure the city's water portfolio tluough sale of Windy Gap water and replacement of the water with water supplies and assets in the Boulder Creek basin that would be capable of multiple uses and would enhance the yield of existing systems. Many of the 1988 RWMP recommendations have been implemented, as follows: The city continues to maximize its exchange yields to malcimize water available to the Betasso Water Treatment Facility and for hydroelectric generation in accordance with City Council direction at the time. • The city has maintained or increased storage levels in the Silver Lake Watershed. • The city maintains a storage reserve in its Boulder Creek basin reservoirs and has converted the Boulder Reservoir Water Treatment Facility to yeaz-round operation. AGENDA ITEM # PAGE • The city sold 43 of its original 80 units in the Windy Gap Project and used the proceeds to purchase additional shares in ditch companies, joint ownership with Boulder County of Caribou Ranch, and the Bazker system. Purchase of the Barker system in 2001 has increased the city's yield from the Barker system and provided additional hydroelectric generation. • The city successfully postponed the construction of additional water treatment facilities unti12004 tluough its water conservation programs. • A Drought Response Plan has been developed for short-term supply shortfalls caused by extreme drought or facility failure. • The city has continued its Watershed Dam Rehabilitation program to provide a safe, reliable water supply system. • The city has replaced both the Silver Lake and Lakewood Pipelines and installed hydroelectric generation facilities on both pipelines. • The city continues to rehabilitate and improve Bazker system pipelines to increase system reliability. • The city protects and enhances the aquatic and riparian ecosystems by providing water flows and managing the Boulder Creek instream flow program as an agent of the Colorado Water Conservation Board. Current information on the impact of climate changes on Boulder's water supplies and possible city responses to clicnate change factors will be included in the SWMP. Climate change-related impacts to Boulder's water supplies is currently under study by Stratus Consulting, and an update to the WRAB on this study will be presented at the September 17 meeting. Many accomplishments have occurred and many things have changed since the 1988 RWMP was completed. The current source water master planning effort will acknowledge those accomplishments and changes and set the course for future source water facilities, resources and policies. Attachments: Attachment A: SWMP Drafr Table of Contents Attachment B: SWMP Draft Section 2- Introduction and Background Attaclunent C: SWMP Draft Section 3- Raw Water Supply System Assets AGENDA ITEM # PAGE This document was created with Win2PDF available at http://www.daneprairie.com. The unregistered version of Win2PDF is for evaluation or non-commercial use only. ATTACHMENT A: SWMP Draft Table of Contents Prepared for City of Boulder, Colorado Source Water Master Plan Prepared by January 2008 MWH Denver, Colorado Contents 1. E~ECU'I'IVE SUM~NARY 2. IN"fRODUCTION AND BACKGROIIND 2.1 PURPOSE OF SOURCE WATER MASTF.R PI.AN 2.1.1 Previous Raw Water Master Plan 2.1.2 Focus of the Source Water Master Plan 2.2 OVERVIEW OF BOULDER~S RAW WATER SYSTEM 2.2.1 Water S~stem Operation 2.2.2 Upper Boulder Creek Basin Sources 2.2.3 Boulder Reservoir Sources 2.2.4 Eschanded Water 2?.~ Instream Flo~v Pullback Water 2.3 HIS"fORY OF THE C1TY WATER SYSTGM 2.3.1 History of Colorado Water Development 23.2 Development of City Water Supplies 2.3.3 Irrigation Ditches 2.4. LEGAL FRAMEWORK 2.4.1 Colorado Water Law 2.~.2 Water Utility Enterprise Fund 2.4.3 Safe Drinking Water Act 2.4.4 Source Water Assessment and Protection Program 2.4.5 Federal Energy Regulatory Commission 2.4.6 City Code 11.1.19 2.4.7 Contracts 2.5 AVAILABLE INFORMATION AND RGLA"fED S'fUD1ES 2.5.1 1988 Raw Water Master Plan 2.5.2 Treated Water Master Plan 2.~.3 Watershed Dams Evaluation 2.~.4 Lakewood Pipeline EIS and Pipe Evaluations 2.5.~ Barker Facilit~~ Assessments 2.~.6 Droueht Plan 2.~.7 Middle Boulder Creek Water Source Management Work Plan 2.~.8 Water Qualit~ Strategic Plan 25.9 Boulder Reservoir Watershed Management Group Resource and Information Guide 2.~.10 Water Conservation Futures Studv 2.5.1 ] Source Water Impact Asscssment 2S.12 lntegrated Evaluation of Boulder Reservoir W'ater Treatment Plant Source Water Protection and Treatment lmprovements 2.5.13 Boulder Valley Comprehensive Plan 2.5.14 Instream Flow Studies 2.5.1 ~ Histon of Boulder's Water Utility 2.~.16 Historic Water System Evaluations 2.G (iIS fLESOURCES 3. RA\i' WATER SUPPLY SYSTEII :1SSF; f S 3.1 LnNn 3.1.1 Sih~er Lake Watershed 3.1? Fourth ofJul~~ Campground 3.1.3 Pard Reservoir Dan Site 3.1.4 Lake~vood Reservoir Site and Lake~~ood f louse 3.1.~ Caribou Ranch 08/13/07 3.1.6 Barker System (Boulder Canyon Hydroelectric Projec[) 3.1.7 Wa[er Source Operations Manager's House 3.1.8 Betasso Water Treatment Facility and Betasso Penstock Corridor 3.1.9 Orodell Hydro Plant Site (Blanchard Intake) 3.1.10 Sunshine Reservoir Site 3.1.1I Boulder Reservoir Lands 3.1.12 W ittemyer Ponds 3.2 MUNICIPAL WA7ER SurPLY INF2nS raUC rua~ 32.1 North Boulder Creek Water Facilities 322 Middle Boulder Creek Water Facilities 3.33 Boulder Reservoir Water Facilities 33 WATERRIGHTSANDWATERCON7RACTS 3.3.1 City of Boulder Municipal Water Rights 33.2 Water Contracts 4. WATER USE, AVAILABILITY AND QUALITY 4.1 WA'IERUSE 4.1.1 Municipal Treated Water Use 4.12 Raw Water Irrigation Use 4.13 Instream Flow Use 4.2 WATER AVAILABILITY 4.2.1 Hydrology 4.22 Major Factors Affecting SVeam Flows 4.2.3 Historical Hydrology - Boulder Creek Basin 41A I-listorical Hydrology - Upper Colorado River Basin 4.2.5 Natural Flow Hydrology 42b Trends Attributable to Climate Change 42.7 DroughtFrequency 43 MUNICIPAL WATER RIGHTS YIELDS 4.3.1 Physical and Institutional Factions Affeaing Yields 4.32 Curren[ Yield Estimates 433 Factors that Could Affect Future Yields 4.4 SOURCE WATER QUALITY 4.41 Ability [o Meet Current Drinking Water Quality Standards 4.4.2 Curtent and Future Land Uses 4.5 SOORCE WATER SELECTION 5. POLICIES, GOALS, AND REGIONAL INFLUENCES 5.1 POLICIES 5.1.1 Boulder Valley Comprehensive Plan 5.1.2 Reliability Criteria 5.2 GOniS 521 Source Water QualiTy Goals 5.22 Source Water Quantity Goals 523 Water Conserva[ion Goals 53 REGIONAL INFLUCENCES AND PARTNERSHIPS 53.1 Northern Colorado Water Conservancy District 5.3.2 W indy Gap Firming 5.33 Southem Water Suppty Pipeline ll 5.3.4 Statewide Wa[er Supply Initiative 5.3.5 South Platte River Endangered Species Agreements 5.3.6 W ildfire Mitigation 53.7 Boulder Feeder Canal 08/13/07 6. ISSUES 6.1. FACILITIES CONDITION AND IMPROVEMEMS 62. OPERATIONS AND MAINTENANCE NEEDS 63. W ATER RIGHTS YIELDS AND PROTECTION 6.4 WATERUSE 6.5. W A'IER QUALITY PROTECTION '/. RECOMMENDATIONS 7.1. PROGRAMS 72. POLICIES 73.PROJECTS S.REFERENCES APPENDIX A- SUMMARY OF RELATED STUDIES APPENDIX B- DEEDS AND AGREEMENTS APPENDIX C - WATER RIGHTS APPENDIX D- INSTREAM FLOW DECREES AND AGREEMENTS APPENDIX E - HYDROLOGY OS/13/07 ATTACHMENT B: SWMP Draft Section 2- Introduction and Background 2. INTRODUCTION AND BACKGROUND 2.1 Purpose of Source Water Master Plan One of the city of Boulder's most important assets is its water supplies. Boulder's founders recognized the importance of a reliable water supply and began developing a water supply system for the growing ciry in the late 1800's. Subsequent generations have expacided and maintained the water system and planned for its future. Cunent citizens of Boulder aze the beneficiazies of these forward-thinking individuals and their efforts in the past. Thoughtful planning for the city's future water needs at this time can help assure that future Boulder citizens also inherit a reliable and sufficient water supply. 2.1.1 Previous Raw Water Master Plan In 1987, the city initiated a public review process to evaluate the water supplies that Boulder owned and discuss options for use of the water. The studies resulted in the 1988 Raw Water Master Plan (RWMP). The focus of the RWMP was more on water yield and water use in the city and less on raw water system infrastructure. Several of the recommendations in the RWMP were adopted for further action by the City Council. One of the key outcomes of the RWMP was adoption of reliability criteria by the Ciry Council for the ciry's raw water supplies. These criteria specified the acceptable level and frequency of water use restrictions in Boulder due to drought. City Council's policy was based on recognition that it was economically impractical to supply water for all uses at all times given Boulder's semi-azid climate. Following this first step towazd long-term drought planni~g, the city took additional steps of setting reliability criteria for the treated water supply system, instituting an on-going water wnservation program, and prepazing a drought response plan. One of the findings of the RWMP was that Boulder owned sufficient water supplies to meet projected municipal demands at build-out. Although City Council did not recommend a permanent reduction in the yield of the ciry's water portfolio through sale of water, they did recognize that the Windy Gap water was the city's most expensive and least reliable water. Council recommended that staff attempt to reconfigure the city's water portfolio through sale of Windy Gap water and replacement of the water with water supplies and assets in the Boulder Creek basin that would be capable of multiple uses and would enhance the yield of existing systems. The city pursued this goal through the sale of 43 of its original 80 units in the Windy Gap Project to the city of Broomfield in 1991. The city used proceeds from the sale to purchase additional shares in some ditch companies, to jointly purchase Caribou Ranch with Boulder Counry, and to purchase the Barker System from Public Service Company of Colorado (PSCo, now known as Xcel Energy). Another important outcome of the RWMP was the deve]opment of instream flow programs for Boulder Creek and it tributaries. The city has workedjointly with the Colorado Water Conservation Board since 1990 to maintain sufficient flow in the creeks to protect riparian habitat. 2.1.2 Focus of the Source Water Master Plan The cunent Source Water Master Plan has been undertaken for several purposes, including the need to update the 1989 RWMP. It is intended to prepare a master plan that can be instrumental Source Water Master Plan Chapter 2 Page 2-1 in supporting the city's efforts to manage its source waters in a sustainable manner that is capable of supporting the city's needs through drought periods without violating the adopted reliability criteria. The mastet plan should provide guidance on maintaining and replacing raw water facilities so that the source water deliveries aze dependable. Finally, the master plan should recognize and be compatible with other city master plans and strategic plans. The scope of the Source Water Master Plan (SWMP) includes several different efforts. Existing information about the city's source water is compiled to provide the necessary basis for future decision making. This collection includes background information, a review of the city's raw water system assets and a review of current operations and maintenance practices. The SWMP will document current policies for management of the city's source water and will review water use levels and water right yields. Emetging issues affecting how the city will manage and operate its source water system in the future will be defined. Finally, the SWMP will recommend future studies and actions that should be under[aken and provide general budgeting information and project prioritization to guide development of the ten-year Capital Improvements Program. 2.2 Overview of Boulder's Raw Water System Boulder's water supply system includes many storage, conveyance, hydroelectric and treatment facilities. The ciry owns approximately 7,200 acre-feet' of reservoir storage space in the North Boulder Creek watershed, owns I 1,700 acre-feet of storage in Barker Reservoir on Middle - Boulder Creek, and has up to 8,500 acre-feet of storage space in Boulder Reservoir. Boulder's .- two water treatment facilities aze the Betasso Water Treatment Facility Plant (WTF), with approximately 45 million gallons pet day (MGD) of treatment capacity and the Boulder Reservoir WTF at about 16 MGD. The city operates eight hydroelectric plants located within the municipal water supply system and sells the electricity to Xcel Energy. Four of these hydro plants are located on raw water pipelines and four are on treated water transmission pipelines. In 2007, the city provided water service to approximately llQ000 people living within the city limits and the azea adjacent to the city. The customer accounts served include about 22,500 single family customer accounts, 2,500 multi-family accounts, 2,050 commercial accounts, 80 indusuial accounts, and 1,500 irrigation accounts. The service azea consists of approximately 58 squaze miles, inciuding all of the azea within the city limits and certain adjacent azeas such as Gunbarrel. The average water use for Boulder since 2002 has been about 20,000 acre feet. According to the 2005 Boulder Valley Comprehensive Plan, the projected build-out population is 124,400 people and the projected build-out treated water demand is 28,600 acre feet. The city should be able to meet this projected water demand in almost all yeazs using the water rights expected to be available to the city at build-out. Water use resfrictions for municipai water customers wi(t be required in serious drought yeazs to reduce demand in those years to less than 28,600 acre-feet. The frequency of these reductions in water availability is not expected to be more often than the reliability criteria for the municipal water system that have been adopted by City Council. ~ An acre-foot is the standard measure for raw (unVeated) water. It is equal to the amount of water that would cover one acre to a dep[h of one foot or about 325,850 gallons. An acre-foot of water could meet the water ceeds of two typical households for a year. Source Water Master Plan Chapter 2 Page 2-2 2.2.1 Water System Operations The operation of the city's water system involves intricate relationships between water rights, water qualiTy, laws and legal agreements, streamflows, reservoir storage operations, transmission pipeline operations, treatment capacity, hydropower production, and water demands. The availability of sufficient water supplies to meet the city's needs is only assured by balancing and managing all of these factors. Boulder owns a diverse poRfolio of water rights and water delivery contracts which allow the city to use water both from the local Boulder Creek basin and from tributazies of the Colorado River. The city's Middle Bou3der Creek and North Boulder Creek water rights aze fed by watersheds on the eastem slope just below the Continental Divide. Boulder also owns rights to delivery of water from the Colorado-Big Thompson Project (CBT) and the Windy Gap Projects. Both of these projects diver[ water from the westem slope and deliver it through the CBT facilities, which are operated by the Northem Colorado Water Conservancy District (NCWCD). Like most western communities, Boulder depends on stored water most of the yeaz. High streamflows from melting snowpack occur for only a few spring and summer months. Natural streamflows in late summer and the winter aze not sufficient to meet customer demands and must be supplemented with previously stored water supplies. The amount of water available also changes from yeaz to yeaz depending on how much snow falls in the mountains. Therefore, Boulder must store water in reservoirs during wetter yeazs to carry over for use in dry years. The city owns seven reservoirs and several natural lakes in the headwaters of the North Boulder Creek basin within the Silver Lake Watershed. In addition, the city owns Boulder Reservoir nor[heast of Boulder and the Barker Reservoir facilities on Middle Boulder Creek. The city also holds decreed exchange rights on Boulder Creek which, in effect, allow the trade of water from sources on lower Boulder Creek for Boulder Creek basin water high in the mountains. Additionally, in droughts or emergencies, the city can draw on water rights that have been dedicated for use in most yeazs for instream flow purposes. The city maintains reliable water supplies throughout every season of the year and through drought periods by filli~g its upper Boulder Creek reservoirs to the greatest extent possible during the spring snowmelt period in the mountains. The city typically has a four- to eight- week window each year during the high streamflow period in the late spring to store the reservoir water that will supply the city through the entire upcoming year and that will also provide water to carry over into the next year as protection against drought. The combination of the city's native basin water storage rights and exchange rights assures that the city's reservoirs fill by mid-June in years with su~cient streamflow in the upper Boulder Creek watershed to do so. Modeling of Boulder's water system shows that the city owns sufficient water supplies to meet the city's projected needs at full build-out of the comprehensive plan azea at the level of reliabiliry specified by City Council. The build-out demand is currently projected to be 28,600 acre-feet annually. In 2001, Boulder used about 24,000 acre-feet of water for municipa] treated water supply purposes. Following the drought year of 2002, water use has dropped to less than 21,000 acre-feet annually. CurrenUy, another 500-1500 acre-feet has been provided for instream flow purposes each year and 2500-3500 acre-feet are rypica]]y leased to agricultural producers annually. The remainder of the city's water portfolio remains available for future municipal ueated water supply, as well as for the multiple use objectives identified by City Council for the city's water resources. Source Water Master Plan Chapter 2 Page 23 Presently, about 35 percent of the city's water supply comes from the Silver Lake Watershed, 35 percent comes from Barker Reservoir, and 30 percent comes from Boulder Reservoir on average. The Silver Lake Watershed and Barker sources are tully used, but the city owns enough water at Boulder Reservoir to meet all of Boulder's future needs. As Boulder grows, the percentage of water delivered from Boulder Reservoir WTF will increase to about half of the city's supply. 2.2.2 Upper Boulder Creek Basin Sources Within the upper basin, water yields are derived from North Boulder Creek and Middle Boulder Creek. Water from both sources is treated at the Betasso WTF. Betasso, the city's largest water treatment plant, is located in the foothills west of Boulder near Sugarloaf Mountain and the Betasso Preserve. Water delivered through this portion of Boulder's water supply system develops enough pressure to produce electricity at the eight hydroelectric plants owned by the city. A schematic of the upper portion of Boulder's water system is shown in Figure 2.1. There are several reservoirs and natural lakes within the city-owned Silver Lake Watershed at the headwaters of North Boulder Creek just below the continental divide. The water from the upper Silver Lake Watershed reservoirs can be delivered into Silver Lake. From there, it can be released for delivery through 5ilver Lake Pipeline and Lakewood Pipeline to Betasso WTF. Additional direct flow diversions from North Boulder Geek and Como Creek can be made into Lakewood Pipeline at a small regulating reservoir known as Lakewood Reservoir outside of _ Nederland. _ On Middle Boulder Creek, the city owns the Boulder Canyon Hydroelectric Project which includes Barker Reservoir. These facilities were purchased from Xcel Energy (formerly Public Service Company of Colorado) in 2001. Barker Reservoir is an 1 1,700 acre-foot reservoir near Nederland. Boulder delivers water from Barker Reservoir into the Barker Gravity Pipeline where it then flows to Kossler Reservoir. Kossler is a small forebay reservoir. Water released from Kossler flows down the Boulder Canyon Penstock2 to the Boulder Canyon Hydro. At this point, water can either flow through the turbines in the hydro plant with subsequent release to Boulder Creek or be carried up to Betasso Hydro and Betasso WTF through the Betasso Penstock. The water is then treated and delivered into the city. 2.2.3 Boulder Reservoir Sources Boulder Reservoir, located northeast of Boulder, was constructed by the city to provide a third source of drinking water. The reservoir and surrounding regional park have also become a popular recreation site. Boulder Reservoir is owned by the city of Boulder, but is operated by NCWCD. The NCWCD operates the Colorado-Big Thompson (CBT) Project and the Windy Gap Project. These two projects divert water from the upper Colorado River on the western slope and deliver it, through a series of tunnels, canals and reservoirs to north-eastern Colorado cities, farms and industries. Almost all of the water in Boulder Reservoir comes from the CBT and Windy Gap Projects through Carter Lake, although water substituted by Left Hand Water District from St. Vrain Creek and deliveries from the Farmers' Ditch add to the water supply. Farmers' Ditch diverts from Boulder Creek near the mouth of the canyon. A schematic of the CBT system is shown in Figure 2.2 '` Apenstoch is a pressurized pipeline that leads to a turbine and a hydroelectric generator. Source Water Master Plan Chapter 2 Page 2-4 Farmers gate c -So ~ S a ;; , ~ ~, ~ v Y ~ `o ~ m ~;~ w v ~ ~ _~ ~ IiEtQS50Q11C P Lakewood Hyd c' --- - ~ ~ 4s C? A G yy t ~ ~ ~v ~ -~~ ~~ ~ ~ • J Boulder Cnnyon H ydro ~_=-` ~a,_~ ~ Koh ler Hydro/PRV Silver Lake t- Hydro ~'----- Silver Lnke Hydro bypass Mokveld " valve LF~ END Hydro Plant ~ Diversion heodgote ~ Valves ~ Treated water reservoir Raw writer reservoir Sunshire PRV . - -- '~l ~~' ` Sunshine Ma> ~ f y /; R, Orodell H dro ~- -- Hydro/ PRV a' ~i,"; ~ ~ ~ - -~ ~,, 101 Pe ar I P ~ ' PRV ~ ~ MaxWeIl \~ P I-tydro/PRV ~~~. ~~ ~ ~ :s~~ ~'~~~' ~ Source Water Master Plan Chapter 2 Page 2-5 The two Boulder Reservoir dams were built in 1955 by the city as a part of an agreement with the NCWCD allowing Boulder into the NCWCD. NCWCD subsequently paid Boulder one-third of the construction cost of the reservoir in exchange for use of storage space. Although Boulder owns the entire reservoir, the NCWCD use of the storage space for which they paid is contracted in perpetuity. Boulder has the right to use 8500 acre-feet of Boulder Reservoir storage space in the winter months and 5143 acre-feet in the summer months. The CBT project was constructed by the Bureau of Reclamation and delivers water only to entities located in the NCWCD. CBT water is managed as a supplemental supply to native basin water. Each year the NCWCD board of directors sets the amount of water, or the quota, to be delivered to each contract delivery right, called a"unit". A 100 percent quota represents one acre-foot delivery per unit. High quotas are typically set when east slope runoff is projected to be below norma) and west slope reservoirs are at or above average storage levels. Low quotas are set when east slope basin runoff is expected to be above normal or west slope reservoirs are significantly below normai storage levels. Figure 2.2: Colorado-Big Thompson Project Facilities 'V~lest Slope Col~ec#ion 5ystem sHanow ~ ~~s~~voi~ WIIIOW CREEK RESERVOlR ~ ~YIIOW w~Ta+r~6tE wG~oi~FE qaen W1NDY ~~" Gronby GAP ~~ RESERVOIR ,,, g RocKy Mountain N~tional ~qf {C IAKE GRANBY $ ,~ . ti .__ ,_ _ F_. ~ i.., ~~~.4+i . w.. (maps from NCWCD) East Slope ~v Distribution - System .e _ _ ~~ . . - ~....L ~ FRSI_aY.~ . ... P.I`!^.F' r ~ ~\., i.~i'"'~~ ~~~ POl€ Nn PINEWOOD 4 Xau".--r T Lwelotod ~ . ~,.rnmre~ RESEitVOIR/~ '~ .~~,~ ~-....,,,.--~.a^~.~ ~r+wryihr~+i-r ~7C~ Y ~ wr ~ Nmrj ~ ~ IAKE ESiES ~%~"~ ~~~ RES£kViDMR GR^'FFCi MG4IM.VW :<' F;fIkR . . . ~~ r~r~. F w ~ ~a, ~~ trs s~~d ~'`r~`°'-~: ~ CARTEH Q ~ ~ ;d«._ °' tJ1KF ~ NGWGD ~ ~ ._ s venin ~~ ' > ~ HEADfiUARTERS .R%91.t A ... j `aH^i .; 5CrUt i`4fv t n1sF 1 tiartb 5L Uci~,6~,~ ~ ~y~y~ .•~ . ~~~V~tVFt?a~c'1~etP~tz~ti. ..~ ,.~.F_ . ~ .. F~`~ ~ t,'~r,'" ..~ t~tayerionl~ ~4~ ~ . . ~ -`*~i ~ ~ °:.~ a'" FE:L#k « ~ ~F ~7 Ceva ~ "_.' _ oa'* ~ _. .. ~ ~. ~ ' .. f~ y Source Water Master Plan Chapter 2 Page 2-6 Boulder owns 21,01 ~ municipal class' units of out of 31 ~.000 units in the CBT project. The city's CBT water can be used for -nunicipal purposes directly through treat-nent at the Boulder Reservoir WTF or as a source of exchange water for Boulder's exchan~e rights on Boulder Creek. Boulder also leases CBT water to agricultural users on Boulder Creek below the Boulder Supply Canal outlet. CBT water is limited to a single use, so there is no opportunity for reuse of this water by the city. The city owns 37 units out of a total of480 units in the Windy Gap Project. The Windy Gap Project was built by a coalition of cities in northeastern Colorado. It delivers water to project participants through the CBT facilities. The Windy Gap water is subordinate to CBT water in the CBT system, so it is possible that the Windy Gap water stored in the system can be spilled to make room for CBT water. It is also possible that the Windy Gap Project water rights may yield very little in dry years because they are junior to many other water rights. Achieving the anticipated project yield of ] 00 acre-feet per unit of the Windy Gap Project depends on the ability to either `'borrow" against the CBT project or have storage available outside the CBT system for use in those years when all storage in the CBT system is filled with CBT water. Boulder does not presentiy plan to participate in any reservoir construction projects to firm the city's Windy Gap units, but plans to use storage space in Barker and Boulder Reservoirs for this purpose. The Windy Gap water is fully consumable. Therefore, Boulder can lease any return flow credits to downstream users. The city has applied for a water decree allowing capture of Windy Gap return flows and exchange back into the city's system. The Farmers' Ditch diverts from Boulder Creek and ends at Boulder Reservoir. The city can take delivery of water through the ditch, including water attributable to Farmers Ditch shares that the city has changed through Watcr Court proceedings to allow municipal use. Thiti Farmers Ditch share water tnust be used on a direct tlow hasis and can't be stored in Buulder Reservoir. Boulder also has use of water derived from an agreement between NCWCD and Left Hand Water District available at Boulder Reservoir. This water, called the "20 Percent Water", is a portion of the excess water resulting from Left Hand's trade of water diverted from Left Hand Creek into the Boulder Feeder Canal for CBT water taken out of the Boulder Feeder Canal at a point upstream at a later time. 2.2.4 Exchanged Water Boulder owns several exchange water rights that allo~~ the trade of water from one source for water from another source on a one-to-one basis. The city can exchange water into storage in its upper reservoirs or can exchange for direct tlow into the raw water pipelines feeding Betasso W TF. Use of Boulder's exchange water rights is necessary in some years whcn the city's native basin water rights are called out of priority. Exchanges help to maintain the csrry-over water levels in the city's Boulder Creek reservoirs to protect against major water shortages during drought periods. Additional water can be taken into storage durin~ higher flow years tor carrying forward 3 CBT units are categorized into classes based on type of use. The city also owns agricultural class CBT units that are held b~ the Open Space and Mountain Parks Department for irrigation purposes. NCWCD policies dictate that agricultural class units cannot be used for municipal ~rater supph~ purposes on an on- eoine basis ~~~ithout undergoing a process to chanee the class and pa} ing additional assessments. Ho~tiever, municipal class units can be used for agricultural purposes. Source Water Master Plan Chapter 2 Page 2-7 into lower flow years through use of exchanges. When water is exchanged for direct diversions into the city's pipelines, stored water that would otherwise have to be released from reservoirs to meet the city's water needs can be tetained for later use. The exchange mechanism is used to continue taking water during the critical spring and summer high flow periods when water is physically available at the high mountain reservoir and pipeline diversion points, even if the city's native basin water righu aze called out by more senior water rights. This is accomplished by satisfying the other water rights with an alternative supply such as CBT water. Only water rights calls coming from a point below the dischazge out of Boulder Reservoir can be satisfied in this mannec Se~ior calls occurring above this point on [he river must be answered by allowing water to pass by the city's storage reservoirs and pipeline diversion points. Efforts aze made to store as much water as possible during the high spring runoff because sheamflows quickly drop to typical summer levels that are too low to allow the city to store water in its reservoirs either under its native basin rights or through exchange. When exchanging, the city Vades water from Boulder Reservoir, Baseline Reservoir, North Boulder Farmers Ditch or Lower Boulder Ditch for additional water at the city's upper Boulder Creek intakes. Boulder can also exchange the limited portion of its wastewater effluent that is allowed to be fully consumed under the city's water rights decrees. Exchanges typically can occur during an exchange season that is almost entirely limited to higher flow periods on the creek. This is also when, in many yeazs, the ciry's reservoirs aze most likely- to be filling under their native basin water rights and the ciry's senior direct flow rights may be yielding enough to fill the city's pipelines without use of exchange. Therefore, water exchanges aze used only when needed because the city's native basin water righu have been called out of priority. The city holds rights of exchange on Boulder Creek and can also exchange against the Boulder and White Rocks Ditch Company diversions, which is called the "intemal exchange:' When exercising the internal exchange, the Boulder and White Rocks Ditch (B& WR) Company diverts less water than it is entiUed to take at its diversion structure on Boulder Creek just west of Broadway. Boulder increases its diversions at Bazker Reservoir or another of the ciry's upper diversion points by an amount equal to the water foregone by B&WR Ditch. The city then pays the ditch company back by introducing an equal amount of the city's CBT water supplies dicectly into the B& WR Ditch from a channel running out of Boulder Reservoir into the B& WR Ditch. The city's right to do the intemal exchange is based on an agreement with the B& WR Ditch. The exchange rights allow the city to cost-effectively move water from the city's lower water system into its upper water system without the need to construct an expensive pipeline. The increase in water available to the city's upper water system also increases hydropower generation. Water treatment costs aze reduced due to use of the exchange because it is less expensive to treat the higher quality water available to Betasso WTF than water at Boulder Reservoir WTF. Also, water from Betasso WTF can be delivered into the ciry by gravity instead of by pumping, as is required for Boulder Reservoir WTF water. This both saves money and reduces greenhouse gas emissions associated with the elecVicity for the pumps. Source Water Master Plan Chapter 2 Page 2-8 2.2.5 Instream Flow Pullback Water The city donated ownership of the use of some of Boulder's water rights to the Colorado Water Conservation Board (CWCB)° in 1990 and 1992 to maintain streamflow levels in North Boulder and Main Boulder Creeks. However, based on City Council direction, the city/CWCB agreement allows the donated water to be used for municipal purposes instead of instream flows in the event of an emergency with the municipal water system or a severe drought. Instream flow use of this water was intenupted in the drought yeaz of 2002 in order to increase the amount of municipal use water available to the city. In addition, the donated water can be used for municipal purposes whenever it is not needed to maintain streamflow ]evels. 2.3 History of the City Water System 2.31 History of Colorado Water Development Prior to the settlement of the West, common law wntrolling water use was based on riparian rights that had been defined through common law. A land owner with a stream running through his property had full rights to take water out of the stream for use upon his land. This approach proved ineffective in the arid West where it was often necessary to transpoR water away from streams to use on land under a mining claim or that was agriculturally viable. In the absence of any govemmental enforcement authority, early settlers adopted a practice of "first in time, first in right" to settle water disputes based on common law practices for settling disputes about ownership of mining claims or other property. The £rst settlers to apply water to a beneficial use gained a preFerential right to access any available water in times of shortage with regazd for the connection between the source of water and the point of use. Therefore, a new law based o~ communiry wstom that came to be known as the prior appropriation doctrine supplanted the common law methods used in the eastern states of riparian water allocation based on ownership of land at the water source. The basis for a water rights claim in Colorado became the continued, non-wasteful application of water to a beneficial use and a right to use water became a transferable property right. In 1862, the Colorado Territorial Legislature incorporated the prior appropriation doctrine into the statutory law of the territory. By this time, twenty-three ditch companies had initiated claims for water rights on Boulder Creek based on actions taken to physically divert water out of the creek, but there was a long way to go before an enforceable water rights system was developed. Even after the prior appropriation doctrine was written into the Constitution of the newly-formed State of Colorado in 1876, no govemment entiry existed to enforce water rights priorities. Disputes were settled by water diverters between themselves based on self-proclaimed water rights that might or might not have been openly declared or registered with the State. This sometimes led to controversies during times of shortage such as one that became the basis for a court case called Coffin v. Left Hand Ditch Company. A downstream water user on the St. Vrain River named Coffin irrigated land adjacent to the river and became frustrated by a lack of flowing ° Under Colorado law, the CWCB is the only entity that can use water that is specifically decreed for non- recreational instteam flow purposes. The city retains title to the water rights that provide the water for instream flow and pays an~ual assessments to the ditch companies of origin for the ditch rights. CWCB has ownership of the right to use the city's water rights for insVeam flow purposes. The city has ownership of the title to the water rights and ownership of the right to use the water for municipal purposes and for downstream agriculmral use. Source Water Master Plan Chapter 2 Page 2-9 water through his properry during a dry period in 1878. Believing that ownership of ripazian land should give a better right to use of water than the right of the upstream Left Hand Ditch Company to cazry water to land away from the river, Mr. Coffin resorted to the self-help method of using dynamite on the Left Hand Ditch headgate. After heated discussions among the parties that reportedly involved tlueats of shotgun use, cooler heads prevailed and the case was taken to the courts. In 1882, the Colorado Supreme Court issued a ruling in the case stating that Prior Appropriation was the only law recognized for water allocation in Colorado and no ripazian rights existed. In I879, while the Coffin case was making its way through the wurts, fazmers on the St. Vrain River requested the governor of the State of Colorado to appoint water commissioners with the authority to decide the relative priorities of ittigation water rights. This non-judicial approach was rejected by the State because it would provide little or no opportuniry for due process for other water users who objected to decisions regazding priority of rights made by the governor's commissioner. Therefore, the State Legislature passed laws requiring that claims for a water right be submitted to the courts for recognition in order to be administered by the State Engineer's O~ce in order of priority as established by the courts. Water righu that may have been put to use at an eazlier date than others, but had not received court recognition could not be treated as senior by the State Engineer's Water Commissioners. A round of basin-wide court hearings ensued that were known as general adjudications. Anyone with a water rights claim was to present evidence to the court oFthe date of their first applicatio~ of water to beneficial use in order to gain a place in line with an adminish~able priority date. Water righu claims that missed the first general adjudications and were not recognized by the court until a later adjudication are considered junior to all rights in the prior adjudication even though the water may actually have been put to use at an earlier date. The first general adjudication in the Boulder Creek basin resulted in a court decree issued by the Bouldet Counry Disttict Court on June 2, 1882. It only involved claims for direct flow irrigation rights and limited rights for domestic uses by irrigation ditch users. The need for decreed water rights for reserVOir storage or rights for uses other than agricultural with incidental domestic use had not yet been recognized. Ninety-eight irrigation ditches in the Boulder Creek basin were adjudicated on that date and prioritized by their appropriation dates. Later genernl adjudications incorporated reservoir rights and rights for municipal and industrial users. This system has evolved into the system we have today where alI filings for new appropriations of water or changes to existing water rights are filed in Water Court to allow review of the proposed beneficial use and to assure no detrimental effects (known as "injury") is caused to other water rights. General adjudications aze no longer used and applicants for water rights may file with the Water Court at any time. 2.3.2 Development of City Water Supplies The city of Boulder began acquiring and developing water supplies for its citizens in its eazliest days as a community. The city began operating a municipal water utility in 1875, in part because Boulder's citizens were already concerned with water quantiry, quality and reliabiliry of water supplies. The first storage reservoir, Sunshine Reservoir, was constructed in 1875 in Sunshine Canyon and was filled through a ditch running from Boulder Creek. However, by 1879, the ciry had atready begun to outgrow this water supply. By the early 1880s, residents were complaining about cloudy water in the municipal water system that had been polluted by mining in the mountains above and west of Boulder and from discharees into the stream from settlements in the Source Water Master Plan Chapter 2 Page 2-10 canyon. City officials began to discuss moving the city's water intake from a point on Boulder Creek, which was located at the mouth of Boulder Canyon, further upstream. By 1890, the city had purchased a piece of land on Boulder Creek near Orodell (located just below the confluence of Boulder Creek and North Boulder Creek at Boulder Falls) and constructed a new upstream intake called the Blanchazd [ntake. A pipeline was constructed from the new intake into the city along the alignment followed by the Boulder Canyon Pipeline today. Citizens hoped that water quality would improve. However, as more and more tungsten mills began operating upstream of the city's new intake, water quality problems once again became apparent. In 1902, the City Council discussed the water quality problems caused by having the water system intake located at the mouth of Boulder Canyon and began discussing the possibility of again moving Boulder's water intake upstream. The City Council developed a plan to acquire ownership of a high-mountain watershed and water rights to supply water, free from pollution caused by the mines and sett(ements, and to pipe the pure water to Bouldec The ciry authorized purchases of land in 1902, but it wasn't until 1904 that the first purchases were finalized. In 1904, the city purchased lands on North Boulder Creek below Arapaho Glacier in what was to become the ciry-owned Silver Lake Watershed. The purchased land contained the Triple Lakes and Oval Lake. A dam was later installed at the outlet to Oval Lake that created a larger reservoir named Goose Lake. In 1906, the city bought Silver and Island Lakes and their storage rights from the Silver Lake Ditch and Reservoir Company. With secure water rights and reservoirs in hand, the city began construction in 1906 of the Boulder City Pipeline running from the Blanchazd Intake at Orodell up to a tiny mining camp called Lakewood just outside of Nederland. The site was downstream of the Boulder County Ranch (now called Cazibou Ranch) where the Primos Tungsten Mill was located. Lakewood Reservoir was built as a forebay for the Boulder CiTy Pipeline. Como Creek was re-chacuieled to prevent its waters, heavily polluted due to mining, from mixing with the purer water of North Boulder Creek as it flowed into Lakewood Reservoir. By 1919, however, it was concluded that an intake was needed at an even higher elevation to avoid contamination of the water supply with mine runoff from the Primos MiIL The Boulder Ciry Pipeline was extended to a point within the boundazies of the Silver Lake Watershed, resulting in two segments called the Lakewood Pipeline and the Silver Lake Pipeline. The upper intake to the Silver Lake Pipeline became known as Boulder City Pipeline Headgate #3, the diversion from North Boulder Creek into Lakewood Reservoir was Boulder City Pipeline Headgate # 1, and the intake from Lakewood Reservoir into Lakewood Pipeline was Headgate #2. Most of the land in the Silver Lake Watershed was purchased by the city from the federal govemment for $1.25 per acre based on three grants made by the US Congress. The grant of the right to pwchase the land was specifically based on the city's need for a water supply. On Mazch 2, 1907, the U.S. Congress made its first grant of land in the Silver Lake Watershed to the city of Boulder. The act (35 Stat., 2155) states that ". ..for purposes of water storage and supply of its waterworks...said city shall forever have the right, in its discretion, to control and use any and all parts of the premises herein conveyed, and in the construction of reservoirs, laying such pipes and mains, and in making such improvements as may be necessary to utilize the water contained in any natural or constructed reservoirs upon said premises." The Congressional Record for the 1907 bill states, °The object and purpose of this bill aze to convey to the city of Boulder, Colo., the lands described in the bill in order to protect the water supply of the said city from pollution, and to accomplish this purpose the land is to be conveyed to the ciry of Boulder......." That same day, Medicine Bow National Forest was expanded by Presidential proclamation to include lands in Colorado. Some of these lands were adjacent to the 1907 Silver Lake Watershed. Source Water Master Plan Chapter 2 Page 2-11 Subsequent acts in 1919 and 1927 withdrew lands previously reserved to the Medicine Bow National Forest (of which the current Arapaho National Forest was once a part) and granted the right to purchase those lands to the city for inclusion in the Silver Lake Watershed for purposes of municipal water supply. These acts state that the United States gave and granted "the lands, together with all associated rights, privileges, immunities, and appurtenances, of any nature, to the city of Boulder and its successors forever." The Silver Lake Watershed contains thirteen reservoirs and natural lakes that are fed by snowmelt and melting of the Arapaho Glacier. This high-quality source of water supply was sufficient to meet all of Boulder's water needs until the 1950's. In the 1950's, a severe drought combined with exploding population growth strained the limits of Boulder's water supply. The city made plans to develop additional water supplies. These efforts resulted in the two additional water sources in use by the city today--Barker Reservoir and Boulder Reservoir. Boulder Reservoir, located northeast of Boulder, was completed in 1955 as a part ofthe agreement that allowed the city to join NCWCD. Barker Reservoir, located on Middle Boulder Creek near Nederland, was owned by Public Service Company of Colorado (PSCo). The city entered into the first of a series of agreements with PSCo in 1954 allowing Boulder to have limited use of the Barker facilities. In 1959, a new agreement was signed with PSCo that gave the city the right to store 4000 acre- ~ feet of water in Barker Reservoir. Under successive agreements, the storage space allotted to the city gradually increased until 1978 when it reached 8000 acre-feet out ofthe 11,686 acre-feet of space in Barker Reservoir. PSCo continued to use the remaining storage space for water to generate electricity at the Boulder Canyon Hydro Plant. In 1963, following years of minimal treatment for the Silver Lake Watershed water, the city constructed the Betasso Water Treatment Facility (WTF) to address ever-tightening drinking water standards and increased knowledge of water-borne pathogens. Land for the treatment facility was donated to the city by Ernie Betasso. He also donated adjacent land to Boulder County for the Betasso Preserve. The treatment plant processes were designed to fit within the confined area at the Betasso site based on the assumption that the quality of water from the Silver Lake Watershed and Barker Reservoir would continue to be protected and the need for plant enlargements would be minimaL The Boulder City Pipeline was replumbed to connect to the Betasso WTF, resulting in segments named the Lakewood Pipeline (which carries raw water to Betasso) and the Boulder Canyon Pipeline (which carries treated water into the city). A new pipeline was constructed running from Boulder Canyon Hydro up the hill to Betasso WTF. For the first time, Boulder used Barker Reservoir water directly rather than by exchange to the Lakewood Pipeline. In the city's water rights decrees, the series of pipeline segments running from Barker Reservoir to Betasso WTF was called Boulder City Pipeline #3. In 1982, a storage restriction was placed on Barker Reservoir due to concerns about the ability of Barker Dam to withstand an over-topping event from flooding. A new agreement was signed with PSCo in 1984 whereby the city paid for repairs to stabilize the dam and gained an "equitable servitude", a perpetua] interest allowing on-going use, in 8000 acre-feet of storage space and in two-thirds of the capacity in the Barker pipeline facilities. In the earfy 1980's plans were developed for hydroelectric plants that would generate electricity using the high pressures developed within the city's upper water delivery system as the water was Source Water Master Plan Chapter 2 Page 2-12 carried into the city from high elevations. Renewable energy generation by the city began when the Maxwell Hydro Plant began operating in 1985. That year, the city generated just over 400,000 kilowatt-hours of electricity. That amount of electricity is sufficient to supply the annual needs of about 50 Boulder County households. During 1986 and 1987, the Kohler, Orodell, Sunshine and Betasso hydroelectric facilities were completed, and the cogeneration facility was constructed. In 1987, the city generated over 2 million kilowatt-hours of electricity or enough to meet the annual needs of almost 300 Boulder County households. The Silver Lake Plant was completed in 1998, and the Lakewood Hydroelectric Project went into commercial operation in June 2004. Throughout the late 1980's and 1990's, the city was interested in acquiring the entire Barker System, but PSCo refused to sell. However, in the (ate 1990's, PSCo merged into a larger utility company that eventually became Xcel Energy. The new company was interested in disposing of assets that were underperforming for power production purposes. The Boulder Canyon Hydroelectric Project, including Barker Reservoir, was purchased by the city in 2001. The primary benefit of owning the Barker System for the city was gaining the ability to operate and maintain the facilities to the standard of reliability necessary for a water utility rather than as a fully-depreciated hydro project. A secondary benef7t is the continued generation of hydropower and the revenues earned by the city from selling the power to PSCo. The Barker System has generated electricity when water was available to do so ever since its original construction. During the 1990's and early 2000's, the city focused on re-building much of the aged raw water delivery system infrastructure. The dams at Lakewood Reservoir and Goose Lake were rebuilt, along with the two diversion structures from North Boulder Creek. The Como Creek diversion was also rebuilt. Lakewood Pipeline and Silver Lake Pipeline were re-constructed. Following purchase ofthe Barker system, the city embarked on a multi-year repair program for the Barker Gravity Pipeline. Repairs have been made to the Boulder Canyon Hydro penstock and the hydro plant turbines and generators. On the Boulder Reservoir side, the intake from the reservoir to the treatment plant was raised to improve water quality ofthe inflowing water. Boulder Water System Timeline Town of Boulder Ditch was constructed to carry water from Boulder Creek into the town's 1875 new water system. Sunshine Reservoir was built by Boulder just west of the town near Red Rocks with an intake from Boulder Creek near the mouth of the canyon. [3oulder's first water supply protection ordinance was passed stating: "No person shall put 1877 any carcass or t7lthy animal or vegetable matter into the reservoir nor shall any person bathe or swim therein or skate upon the ice which may form thereon in cold weather." ~ 87g Sunshine Reservoir capacity was inadequate to serve the growing population and the town ~ometimes ran out of water. 1~~~ Water running in Boulder's water system was turned offwhen dead horses were found in Source Water Master Plan Chapter 2 Page 2-13 Boulder Creek above the town's intake. 18~~ A new Sunshine reservoir was built at an elevation 100 feet higher. The Blanchard intake was constructed upstream on Boulder Creek at Orodell. Planning began for avoiding creek pollution by building a system of reservoirs and 19Q2 pipelines at a higher point in the watershed above mining activity. Water use restrictions were instituted because of drought. ['he first land for what will become the Silver Lake Watershed was purchased near the I904 Continental Divide, including Triple Lakes and Oval Lake. Lakewood Reservoir was built near Nederland. Lakewood Pipeline was completed at a 1906 cost of $155,000 to carry water from Lakewood Reservoir to Boulder. Silver Lake and Island Lake Reservoirs were purchased by Boulder from the Silver Lake Ditch Company ,.~,:;~ ,;_,, which was owned by J.P. Maxwell, developer of Mapleton Hill. The federal government issued the first of three grants that allowed Boulder to purchase 1907 I ~57 acres of high altitude land on North Boulder Creek which became Boulder's Silver ~ Lake Watershed. The city began construction and enlargement of municipal water storage reservoirs within the Silver Lake Watershed area. 1908 I3arker Meadow Dam and the Boulder Canyon Hydroelectric Plant were constructed by an to clectric power company that is later purchased by Public Service Company of Colorado 1914) 1911 .A mining camp at Albion was purchased by the city. 1913 T'he construction of Albion Reservoir was completed Following outbreaks of typhoid fever, City Council discussed hiring guards for the Silver 19~~ Lake Watershed. Council took an inspection tour following reports of pollution in the Silver Lake Watershed from campers and tourists. Based on the Council visit, the area was tenced and closed by 1920, and a watershed caretaker was hired. Boulder's first "water treatment plant" was built near Lakewood Reservoir consisting of a 1417 shed where chlorine and aluminum sulfate were d~unped into Lakewood Pipeline at irregular seasonal intervals. 1919 Silver Lake Pipeline was built from the Silver Lake Watershed to Lakewood Reservoir to avoid contamination from tungsten mining above the Lakewood Pipeline intake. Source Water Master Plan Chapter 2 Page 2-14 '! A second grant was issued by the federal government allowing Boulder to purchase 400 ! acres of land to add to the Silver Lake Watershed. Congress approved Boulder's purchase of 3,689 acres of federal land including Arapaho ~ 927 Glacier and 4 peaks along the continental divide for $4,618. The deed to the city of Boulder is signed by President Herbert Hoover in 1929. This is added to the Silver Lake Watershed. 1928 The outlet for Silver Lake was lowered to gain access to more water. 1935 Green Lakes were purchased by the city. Civilian Conservation Corps crews worked in the Silver Lake Watershed. Northern Colorado Water Conservancy District was formed to contract with the Bureau of 1937 Reclamation to bring water from the western slope as a supplemental supply for northeastern Colorado. 1y39 Work was started on the reconstruction of Lakewood Pipeline. The project was suspended diie to a shortage of steel during WW Ii and was not completed until I954. 1940 Silver Lake dam was rebuilt. Chlorine was added to water year-round at Lakewood Reservoir instead of seasonally. 1449 Studies showed that increased water needs of Boulder's large post-World War Il population would exceed Boulder's existing water supplies. ~ ~~3 Boulder became a member of the Northern Colorado Water Conservancy District and acquired contract water delivery rights for the Colorado Big Thompson Project (CBT)_ The most severe drought year in the recorded record until 2002 occurred. The drought continued until 1957. Boulder entered into an emergency agreement with PSCo to 1954 exchange water from Baseline Reservoir into Barker Reservoir for later release in exchange tor direct diversions at Lakewood Reservoir. Silver Lake Pipeline was rebuilt using 1906 , pipe salvaged from the Lakewood Pipeline reconstruction. 13oulder Reservoir was built and tilled from Carter Lake with CBT water diverted from the 1955 western slope. Boulder entered into an a~reement with PSCo allowing on-going city use of storage space in Barker Reservoir. Source Water Master Plan Chapter 2 Page 2-15 1959 rhe Barker Aeservoir agreement with PSCo was revised to allow Boulder use of 4000 acre- feet of storage space to be increased to 8000 acre-feet over time. 1963 =- Betasso Water Treatment Facility was constructed to filter the drinking water. A pipeline was constructed to allow the city to deliver Barker Reservoir water directly into Betasso. 1966 Skyscraper Reservoir was acquired by the city from Everett Long. Fluoridation of drinking water was approved by Boulder voters. Six northeastern Colorado 1969 cities, including Boulder, initiated the Windy Gap Project to deliver municipal water through CBT facilities Boulder Reservoir Water Treatment Facility was built with a capacity of S MGD. CBT 19'71 ' water was treated and used directly by Boulder for the first time instead of exchanged for Boulder Creek water. 1972 Boulder's right to use Barker Reservoir storage space increased to 8000 acre-feet. 1976 - Betasso Water Treatment Facility was doubled in capacity to 45 MGD. 1'9$2 A pump was added to Boulder Reservoir WTF allowing water to be taken into the treatment plant from both Boulder Reservoir and Boulder Feeder Canal. ~~::: ~~3 A contractor working at Goose Lake caught the timber cribbing on fire and the upper ~~ ~~ ~~~~~~~ ~ portion of the dam burned. ~; The first hydroelectric plant on Boulder's water system was built. Boulder entered into an 1984 agreement with PSCo allowing the city to permanently use 8000 acre-feet of storage space in Barker Reservoir L~g~ Efforts to reach an agreement with the U.S. Forest Service for the reconstruction of Lakewood Pipeline began. ~ ~~~ The city completed the Raw Water Master Plan and adopted reliability criteria for the raw water supply system. 1990 Source Water Master Plan Chapter 2 Page 2-16 The city entered into an agreement with the Colorado Water Conservation Board (CWCB) to donate city water for use for instream flows in North and main Boulder Creeks. 1991 E3olilder sold 43 units out of its 80 units of Windy Gap water to the city of Broomfield. 1993 ~~ decree was issued by the Water Court approving the city/CWCB instream flow program and program operations began. 1994 The spillway structure at Lakewood Reservoir failed dramatically, causing the reservoir to empty overnight_ The spillway was rebuilt and the dams were rebuilt in 1996. 1995 ~xtremely high spring runoff flows caused the city's two diversion structures from North Boulder Creek to fail. Both were rebuilt to allow measurement of instream flow releases. 2000 (~he upstream face of Goose Lake dam was rebuilt. The reconstruction of Silver Lake Pipeline was completed. Barker Reservoir and Boulder Canyon Hydro Project facilities were purchased from Public 20d1 Service Company for $12.4 million. Work to repair the Barker Gravity Line began. An easement agreement for the Lakewood Pipeline was signed ending the effort to reach ~ ~ agreement with the USFS that began in 1986. 2002 The most severe drought in three hundred years caused mandatory water use restrictions to Ue implemented in Boulder. Water use drops by 20percent. 2a~~ ~Che Lakewood Pipeline reconstruction was completed and the new pipeline went into scrvice along with the new Lakewood Hydro. The city now operates eight hydro plants. 2.3.3 Irrigation Ditches By the fall of 18~9, the first irrigation ditches diverting from Boulder and South Boulder creeks had been dug. By the late 1870's, the original versions of most of the irrigation ditches in Boulder Valley were completed. Smaller ditches were dug by farmers using teams of oxen or horses. Larger ditches were sometimes dug by railroad contractors due to the large labor force required. Owners of the ditches often formed ditch companies to share the burden of construction and maintenance among the company shareholders. Early ditches served as the city's first domestic water system as well as irrigation facilities. Laterals carried water from ditches to individual houses and to public spigots in the center of town from which people would collect Source Water Master Plan Chapter 2 Page 2-17 their domestic water in buckets. Information on the history of the Anderson Ditch, Farmers Ditch, and Silver Lake Ditch aze attached in Appendix _. Much of the land within the present Boulder city limits was once farmland inigated by irrigation ditches. Most of these ditches aze still in existence and carry inigation water through the urban azeas for use on private yazds, pazks, campus areas, or farmland at the edge of the city or as far as Weld Counry. There aze over twenTy irrigation ditches spanning over thir[y miles within Areas I and II defined in the Boulder Valley Comprehensive Plan (Table ~. There are more than ten additional irrigation ditches in Area III. The ditches are owned and maintained by private ditch companies, most of which operate under the provisions for mutual ditch corporations in the Colorado State Statutes. Shazeholders in the companies pay assessments for operation and maintenance of the ditches and aze entitled to receive a pro-rata portion of the water carried in the ditch based on their ownership of ditch company shazes. The ciry is a shazeholder in many of these companies, but its shazeholder rights aze no different than those of the private shazeholders. The ditch company remains a private corporation even if a portion of its shazes are owned by the city. In many locations where city transpor[ation or drainage activities have affected the ability of the private ditch company to maintain the facilities, the city has entered into an agreement with the ditch company to maintain sections of a ditch. The ciry has created a database to track transportation and utility maintenance activities, includ~hg on ditches. In general, the active ditches within the ciTy aze in good to fair condition. Many sections of the ditches have become part of the natural landscape, while other sections have been piped or lined with concrete. In some locations, the remnants of old laterals that aze no longer used to cazry irrigation water can still be seen. Although many residents refer to the irrigation ditches as creeks and believe they aze natural waterways, inigation ditches have distinct differences from natural streams. Ditches aze constructed so that they run perpendiculaz to the slope of the land rather than with the slope as water naturally tends to do. The ditches were constructed in this manner to transpor[ water as faz as possible away from the stream and to allow inigation of the greatest amount of land below the ditches. This configuration results in an unnattval channel with very minimal slope and a large tendency to seep water and create or contribute to locally high water tables. Some ditches have been lined or aze periodically sealed to minimize seepage, particulazly in urban azeas. However, ditch companies are not generally liable for damages from what is considered normal seepage, especially to buildings constructed below the ditch long after the ditch was first established. The unnatural configuration of ditches also means that a great deal of sediment settles out of the water as it flows along the minimally-sloping ditch and that there is constant water pressure against the downhill bank of the ditch. Therefore, irrigation ditches must be rebuilt using heavy equipment every decade or so to remove sediment buildup and restore the downhill bank. If development has encroached on the ditch channel, ditch maintenance efforts using the required heavy equipment can become difficult. Urban encroachment on irrigation ditches has often created conflicts between ditch companies and their neighbors since urban dwellers may not understand the legal rights of ditch owners. . Ditches most often are located on prescriptive easements that azise by use of the land for the given purpose over time. Under Colorado law, "open and notorious" use for a specific purpose Source Water Master Plan Chapter 2 Page 2-18 for a period of eighteen yeazs creates a prescriptive easement that is binding on the underlying property owner. These prescriptive easements aze rarely recorded o~ public records, so new property owners often do not uriderstand the access and maintenance rights held over their property by the ditch company and may not understand that their property is considered the "subservient estate" and the ditch company's easement is the "dominant estate". In addition, there aze often agreements that have been entered into by prior property owners who desired to move or enclose the ditch that require the property owner and his successors to maintain the ditch structure at their expense. Prescriptive easements aze not limited to a certain width, but instead give the right to access for whatever activiry is "reasonable and necessary" to operate and maintain the facility. This is often defined by the easement owner's historic use practices. For ditch companies, this usually includes access to the ditch for ditchriders and heavy equipment, the right to remove anything that interferes with maintenance or operation of the ditch including trees, and the right to place material and debris cleaned out of the ditch adjacent to the ditch without obligation to haul it away. The easement continues to exist even if it is only exercised at infrequent intervals. If a resident builds a structure such as a patio or bridge, or plants Vees or bushes adjacent to the ditch, the ditch company has no obligation to protect the structure or landscaping if it is damaged or must be removed during ditch maintenance activities, even if it has existed £or many yeazs. PropeRies downstream of ditches are susceptible to flooding or seepage during normal ditch operations. Solutions to seepage problems for property owners below a ditch bank include sump pumps, French drains, and ditch liners or sealants. It is typically the responsibiliry of the property owner to install seepage protection for the improvements they have made after the ditch was in existence. Likewise, it is the proper[y ow~er's responsibility to remove any dead or dying trees neaz the ditch bank, although the ditch company has the right to remove any vegetation that interferes with ditch operations. Property owners should not cut down the height of ditch banks, destabilize ditch banks by cutting into them or planting trees on them, or throw trash or debris into the ditch because the liability for any ditch overtopping, seepage or flooding caused by these actions is not the liability of the ditch company. In order to minimize conflicts, the ciry has established agreements with a few ditch companies stating that, if the company places debris from the ditch at designated deposit sites, the city will remove the debris. The Utilities Division and Planning and Development Services have been working closely in recent yeazs to develop a protocol to protect ditches from urban encroachment and protect developments from effects of potentially high water tables. When residents seek a building permit for a permanent structure to be placed near an existing ditch banks, the city may require that the residents receive approval from the ditch company to assure that the company's easement rights are not affected. The city has signed an agreement with the Anderson Ditch Company to carry ciry stormwater through iu facilities. The city pays the ditch company an annual assessment for stormwater caniage. The Anderson Ditch intercepts and carries much of the stormwater generated from University Hill in the azea south of Boulder Creek, east of Broadway and noRh of Beaz Creek. Most of the development in University Hill occurred long before any standards existed for design of stormwater facilities. At that time, storm runoff was simply directed towazd the neazest channel that could carry it away, which was often an irrigation ditch. The Anderson Ditch Company has agreed that all excess carrying capacity in the ditch above that needed to carry shareholder or contract water is reserved for the city to carry stormwater. Source Water Master Plan Chapter 2 Page 2-19 Other ditches running through the city also receive stormwater dischazges throughout their length. However, the city has not entered into any other ditch-wide stormwater caniage agreements because these other ditches aze not as heavily impacted by storm drainage as is the Anderson Ditch. The city has entered into agreements with other ditch companies regazding specific azeas of the ditch that may be impacted by changes in historic storm drainage. For example, the ciTy entered into an agreement with the Fazmers Ditch Company regazding the area azound the North Boulder Recreation Center so that stormwater dischazges from the site could be increased over historic levels. The ciry and the Fazmers Ditch Company have aci agreement that allows the city to carty "foreign" water from other sources through Faaners Ditch to Boulder Reservoir for municipal water supply. The city pays an annual assessment related to the ditchrider's' salary to allow the city to carry foreign water. Table 2-xx: Partial List of IrrigaHon Ditches within the Boulder Valley Ditch WaterSource Ditch WaterSource Anderson Ditch Boulder Creek Leggett Ditch S. Boulder Creek Boulder and Whiterock Ditch goulder Creek McCarty Ditch Boulder Creek Boulder and Lefthand Ditch goulder Creek McGinn Ditch S. Boulder Creek Boulder Feeder Canal CBT~ndy Gap N. Boulder Farmers Ditch Boulder Creek Butte Mill Ditch Boulder Creek Schearer Ditch S. Boulder Creek Dry Creek No. 2 Ditch S. Boulder Creek S. Boulder Bear Creek Ditch S. Boulder Creek Farmers Ditch Boulder Creek S. Boulder Canon Ditch S. Boulder Creek East Boulder Ditch S. Boulder Creek Silver Lake Ditch Boulder Creek Enterprise Ditch S. Boulder Creek Smith and Gozs Ditch Boulder Creek Howard Ditch S. Boulder Creek Star Ditch LeR Hand Creek Howell Ditch Boulder Creek Wellman Ditch Boulder Creek Jones and Donnelly Ditch S. Boulder Creek Figure map of local ditches 2.4 Legal Framework The ciry of Boulder operates its water supply system within the legal boundazies of many statutory laws, state constimtional provisions, federal laws, contracts, the City Charter and City 5 Ditchrider is the traditional tertn used for the person who operates and maintains an irtigation ditch for a ditch company. It derives from the time when ditch personnel would ride horses along the ditch bank to monitor the ditch. Source Water Master Plan Chapter 2 Page 2-20 Council adopted plans and policies. This legal framework both guides and conshains the activities that the city conducts through the Water Utility. 2.4.1 Colorado Water Law Understanding the city's water rights requires some familiariry with Colorado's water law doctrine, often summazized as "first in time, first in righY'. The prior appropriation doctrine is the basis of a proper[y rights-based water allocation and administration system which encourages efficient use of a finite resource. Under this doctrine, anyone can establish a right to divert water from a stream as long as that water is put to a beneficial use. This system guazantees security by defining and protecting the right to use water and providing a predictable method of water allocation during dry periods. It assures reliability by giving asswance that the right of use will continue to be recognized and enforced over time as a vested property right. The system is flexible because the right of use can be transferzed to another water user if other appropriators would not be injured by the change. A water right in Colorado is characterized by several factors. These factors include the yield of the water right based on the senioriry of its priority date (the date that the right was first established), decreed uses (municipal, agriwltural, etc.), location of its point of diversion, accessibility to delivery systems and facilities, availability of storage, water quality, institutional restrictions on use, and mazket competition for purchase of water. The city's water rights range in priority date from 1859 to 2001 (very senior to veryjunior.) A water right can only be used in a manner that does not injure the use of more senior water rights. In order for the owner of a water right to legally divert water, there must be sufficient sVeamflow to allow all other more senior water rights to concurzently be fully satisfied. Senior water rights can usually diver[ during periods of both low and high streamflow while junior water rights ofren can only divert during high flow periods. A water right is said to be "in priority" when there is sufficient flow to allow it to legally divert water. Otherwise, the diversion is "out of prioriTy". If a senior water right is not being satisfied at a time when junior rights are diveRing, the senior water right owner can place a"call° against the junior right and cause it to stop taking water or to be "called out " Following application to beneficial use, unconsumed water in the form of retum flows must be made available to fill subsequent appropriations Water rights can be decreed for direct use, for storage and later use, or for exchange. An exchange right allows the holder to satisfy senior water rights by adding water to a stream from a downstream source in exchange for diversion of a like amount of water upstream. The facilities required to use a water right often take a long time to build. Colorado water law recognizes this, and such facilities need not be in place when a water right and its priority date are established. A right is labeled "conditional" until proof is shown in water court that actual water diversions have taken place under the water right, after which it is labeled "absolute". Water rights aze property rights, severable from the land, and may be bought, sold or transfened to another type of use through court proceedings so long as no other water rights are adversely affected by such actions. The State Engineer administers all water rights within each river basin according to the priority system. For this purpose, Colorado is divided into seven divisions, corresponding to the major river basins in the state. These divisions aze further subdivided into districts which enwmpass local sub-basins. Each district is administered by a water commissioner employed by the State Source Water Master Plan Chapter 2 Page 2-21 Engineec The Boulder Creek sub-basin makes up Water District 6, which lies in Division 1, the South Platte River Basin. Boulder owns a diverse portfolio of water rights and water delivery contracts which allow the city to use water both from the local Boulder Creek basin and from tributazies of the Colorado River. The city's Boulder Creek and North Boulder Creek water rights are fed by watersheds on the eastern slope just below the Continental Divide. Boulder also owns units of the Colorado-Big Thompson Project (CBT) and the Windy Gap Projects. Both of these projects divert water from the westem slope and deliver it through the CBT facilities, which aze operated by the Northem Colorado Water Conservancy DisVict (NCWCD). The city also holds decreed exchange rights which, in effect, allow the trade of CBT water in Boulder Reservoir and water in Baseline Reservoir for Boulder Creek basin water high in the mountains. Additionally, in droughts or emergencies, the city can draw on water rights that have been dedicated for use in most years for instream flow purposes. 2.4.2 Water Utility Enterprise Fund By virtue of Article XX of the State Constitution (Home Rule of Cities and Towns) and the City Charter, the Utilities Division provides water, sewer and stormwater services. The city operates its water, sewer, and stormwater systems as individual "enterprises" for purposes of Article X, Section 20 of the State Constitution. The Utilities Division of the Public Works Department directs the day to day operations of the three utilities. Although each utility is financially independent, all three aze managed in an integrated fashion. The Boulder Revised Code (BRC) Section 11-1-2 defines the city's water utility as an enterprise "Water utility enterprise" means the water utility business owned by the city, which business receives under ten percent of its annual revenues in granu from all Colorado state and local govemments combined and which is authorized to issue its own revenue bonds pursuant to this code or any other applicable law. The Water Utility Enterprise is further defined by BRC ] 1-1-55: In addition to any of the powers it may have by virtue of any of the applicable provisions of state law, the Ciry Charter, and this code, the water utility enterprise shall have the power under this chapter: (a) To acquire by gift, purchase, lease, or exercise of the right of eminent domain, to construct, to reconstruct, to improve, to better and to extend water facilities, wholty within or wholly without the city or paRially within and partially without the city, and to acquire in the name of the city by gift, purchase, or the exercise of the right of eminent domain water righu, lands, easements, and rights in land in connection therewith; (b)To operate and maintain water facilities for its or the city's own use and for the use of public and private consumers and users within and without the territorial boundazies of the city; (c)To accept federal funds under any federal law in force to aid in financing the wst of engineering, azchitectural, or economic investigations or studies, surveys, designs, plans, working drawings, specifications, procedures, or other action preliminary to the construction of water facilities; Source Water Master Plan Chapter 2 Page 2-22 (d)To accept federal funds under any federal law in force for the construction of necessary water facilities; (e)To enter into joint operating agreements, contracts, or arzangements with consumers concerning water facilities, whether acquired or constructed by the water utiliry enterprise or the consumer, and to accept grants and contributions from consumers for the construction of water facilities; (~To prescribe, revise, and collect in advance or otherwise, from any consumer or any owner or occupant of any real property connected therewith or receiving service therefrom, rates, fees, tolls, and chazges or any combination thereof for the services fumished by, or the direct or indirect connection with, or the use of or any commodity from such water facilities; and in anticipation of the collection of revenues of such facilities, to issue revenue bonds to fina~ce in whole or io part the cost of acquisition, construction, reconsVuction, improvement, betterment, or extension of such facilities; and to issue temporary bonds until permanent bonds and any coupons appertaining thereto have been printed and exchanged for the temporary bonds; g)To pledge to the punctual payment of said bonds and interest thereon all or any part of the revenues of the water facilities or of wastewater facilities under Chapter I 1-2, "Wastewater Utility," B.R.C. 1981, including the revenues of improvements, betterments or extensions thereto thereafter constructed or acquired, as well as the revenues from existing water or wastewater facilities; (h)To enter into and perform conVacts and agreements with other govemmental entities and utility enterprises for or conceming the planning, construction, lease, or other acquisition and the financing of water Facilities and the maintenance and operation thereof; (i)To make all contracts, execute all instruments, and do all things necessary or convenient in the exercise of the powers granted in this section or elsewhere in state law, the City Charter, or this code, or in the performance of iu covenants or duties, or in order to secure the payment of its bonds if no encumbrance, mortgage, or other pledge of property, excluding any pledged revenues, of the water utiliry enterprise or city is recreated thereby, and if no property, other than money, of the water utility enterprise or city is liable to be forfeited or taken in payment of said bonds, and if no debt on the credit of the utility enterprise or ciry is thereby inwrred in any manner for any purpose; and (j)To issue refunding bonds pursuant to this code or other applicable law to refund, pay, or discharge all or any part of its outstanding revenue bonds issued under this article or under any other law, including any interest thereon in aneazs or about to become due or yield reduction payments required to be made to the federal government to maintain the tax-exemption of interest on the refunding or refunded bonds, or for the purpose of reducing interest costs, affecting a change in any particular year or years in the principal and interest payable thereon or in the related utility rates to be charged, affecting other economies, or modifying or eliminating restrictive contractual limitations appertaini~g to the issuance of additional bonds or to any municipal water and wastewater facilities. Source Water Master Plan Chapter 2 Page 2-23 2.4.3 Safe Drinking Water Act The Safe Drinking Water Act (SDWA) was originally passed by Congress in 1974 to protect public health by regulating the naUOn's public drinking water supply. The law was amended in 1986 and 1996 and requires many actions to protect drinlcing water and its sources: rivers, lakes, reservoirs, springs, and ground water wells. (SDWA does not regulate private wells which serve fewer than 25 individuals.) SDWA authorizes the United States Environmental Protection Agency (US EPA) to set national health-based standazds for drinking water to protect agaiast both naturally-occurring and man-made contaminants that may be found in druilcing water. US EPA, states, and water systems then work together to make sure that these standards are met. Originally, the SDWA focused primazily on treatment as the means of providing safe drinking water at the tap. The 1996 amendments greatly enhanced the existing law by recognizing source water protection, operator training, funding for water system improvements, and public information as important components of safe drinking water. This approach ensures the quality of drinking water by protecting it from source to tap. To ensure that drinking water is safe, SD WA sets up multiple barriers against pollution. These barriers include: source water protection, treatment, distribution system integrity, and public information. Public water systems are responsible for ensuring that contaminants in tap water do not exceed the standazds. Water systems treat the water and must test their water frequently for , specified contaminants and report the resulu to states. If a water system is not meeting these standazds, it is the water supplier's responsibility to notify its customers. Many water suppliers including the city now aze also required to prepaze annual reports for their customers. The public is responsible for helping local water suppliers to set priorities, make decisions on funding and system improvements and establish programs to protect dricilcing water sources. Water systems across the nation rely on cirize~ advisory committees, rate boazds, volunteers, and civic leaders to actively protect this resource in every community in America. 2.4.4 Source Water Assessment and Protection Program Source water protection is the first, and a very important, barrier against contaminated drinking water and focuses on actively keeping contaminants out of exiting and future source water supplies. This is accomplished by reducing or eliminating human activity in and around water supplies, constructing protection baniers between existing land use activity and the water supply or isolating Ute source water from contamination within an enclosed structure. The Safe Drinking Water Act has mandated source water protection as a primary barrier against contamination of the nation's drinking water. This mandate is being implemented through the State of Colorado Source Water Assessment and Protection Program (S WAPP). S WAPP has five essential elements: (1) Watershed delineation, including trans-basin diversions; (2) Inventory of all actual and potential sources of contamination, including the name and address of polluters where known; (3) Determination of susceptibility of a Public Water Supply to those contaminants; (4) Inforcning the public of the existence of those contaminants in their drinking water supply through the acumal Consumer Confidence Report; and (5) Implementing protection of drinking water from those contaminants. Source Water Master Plan Chapter 2 Page 2-24 Actual and potential sources of contamination to source waters aze to be identified under the SWAPP including polluted runoffor potential releases from agricultural and industrial activities, manufacturing services (i.e., gas stations, maintenance shops), utilities, roads, accidental and deliberate hazazdous material dumping, residential development, septic systems and recreation activities. Current regulations require reporting all contaminant sources, by name and address where known, in each annual Consumer Confidence Report. The city of Boulder has actively participated in the state S WAPP and has developed an internal mo~itoring program to chazacterize source water quality and identify sources of pollution. Detailed Geographic Information System maps of the city's source water watersheds were delineation as part of Phase I of SWAPP (see Figure XX). Phase 2 effoRs identified the location of potential sources of contamination (PSOC's) within the watershed delineated azeas in relation to surface water and treatment plant intakes. In Phase 3 of S WAPP the state used computer softwaze to generate PSOC risk and vulnerability assessments based on Phase 1 and 2 information. This process did not incorporate some key utility information and used generalized statewide data for Boulder and other communities. This process did not prove to be beneficial for Boulder since the location of some pollutant sources were found off by lazge distances, or some sowces were not even identified. Boulder has identified a need to reassess the point and non-point PSOC's within their watershed delineation areas to determine water supply vulnerabilities. This assessment could be done in-house with some guidance and direction. With accurate PSOC vulnerability assessments, additional protection strategies and plans would then be developed to protect Boulder's drinking water supplies. 2.4.5 Federal Energy Regulatory Commission The Federal Energy Regulatoty Commission (FERC) holds the responsibility in accordance with the Federal Power Act of 1935, as amended, for issuing licenses for the construction of new hydroelectric projects, issuing licenses for the continuation of existing hydroelecVic projects (relicensing), exemptions from licensing requirements, and oversight of all ongoing hydroelectric project operations, including dam safety inspections and environmental monitoring. The FERC issues both licenses and exemptions from licensing for hydroelectric facilities based upon a series of criteria including generation capaciry, design and configuration and ownership of affected lands. The city currently holds seven conduit exemptions from the FERC for its Silver Lake, Lakewood, Betasso, Orodell, Maxwell, Kohler and Sunshine Hydroelectric Projects. Conduit exemptions apply to hydroelectric projecu which utilize the hydroelectric potential of a conduit which most often exists for purposes other than hydroelectric power generation. The city's exempt hydroelectric facilities aze all located on pipelines or conduits which exist primarily for raw or treated municipal water transmission. Exemptions from licensing are issued in perpetuity and contain conditions concerning project operation and maintenance. Hydropower licenses are issued by the FERC for hydroelectric facilities of,lazger (greater than 5 megawatts) generation capacity which may include a dam for development of hydropower potential and which generally include a lazger area of effect than small hydropower projects. Licenses aze generally issued for a term of 30 to 50 yeazs. The Boulder Canyon Hydroelectric Project, which includes Bazker Dam and Reservoir, is a licensed facility. The current license was issued to Public Service Company of Colorado on Apri128, 1981, was transferred to the city upon its purchase of the project in 2001 and will expire on August 31, 2009. The city is following Source Water Master Plan Chapter 2 Page 2-25 FERC requirements for authorization to continue operating the Boulder Canyon Hydro after the current license expires. Dam safety is a critical part of the FERC's hydropower program. Prior to construction, the FERC reviews and approves the designs, plans and specifications for dams, powerhouses and other structures. Once construction is complete, the FERC requires continuing project inspection on a regulaz basis. All licensed dams are required to have a~ Emergency Action Plan which must be updated and practiced annually. 2.4.6 City Code 11.1.19 There aze many ordinances contained in the City Code, B.R.C. 1981, which affect the Water Utility. Most of these ordinances aze contained in the following sections: Section 11-1-13 When Connections with Water Mains aze Required Section 11-1-14 Permit to Make Water Main Connections Section 11-1-19 Water and Ditch Rights Secrion 11-1-20 Taps or Connections to Water Mains Section 11-1-42 Agreement to Extend Water Mains Section 11-1-43 Reimbursement of Costs for Water Main Extension This list does not include the sections setting forth the actual fees found in Chapter 4-20. Most of '' " the ordinances which relate to source water aze contained in Section ] 1-1-19. Presently, the code requires immediate hook-up to the water utility upon annexation for commercial or public facilities if shvctures exist or are proposed and if they aze adjacent to a water main. Presumably, if such a main is built, then immediate connection could be required. Private proper[ies with existing or proposed structures must also connect if they abut a water main. However, Moore's Subdivision properties annexed as of July 11, 1986 are exempt from these requirements, as aze any other properties that enter into a written agreement with the city. See Section 11-1-13, B.R.C. 1981. Fees shall be paid when the City Manager notifies property owners that such fees aze due. The code requires payment of such fees at time of permit issuance (see Sections 11-1-14 and 11-1-20, B.R.C. 1981), and it is clear that no one shall fail to pay the costs for a tap. Annexation agreements may change the timing of payments and in the past such agreements have allowed for the deferral of payment of fees. Developers or subdividers may extend water mains and be reimbursed for such costs. See Sections 11-1-42 and ll-1-43, B.RC. 1981. Sectio~ 11-1-19 of the Ciry Code addresses transfer of water and ditch rights upon annexation, subdivision and redevelopment. The city has adopted ordinances that require owners of water and ditch iighu to offer to sell their rights to the city at the time of applicatio~ for water service or annexation. Conditioning municipal water service upon the dedication of water rights is a common requirement for both annexation and water service in Colorado so that developing properties are responsible for off-setting impacts caused to public services. The first sentence of 11-1-19(a) requires that applicants for city water service shall offer for sale to the city all water and ditch rights if any one of the following tluee conditions apply: • The person has voluntazily annexed and is applying for city water service; Source Water Master Plan Chapter 2 Page 2-26 • The person has unilaterally annexed and is applying for city water service; or • The person is a Silver Lake Ditch and Reservoir Company shazeholder. However, there are 2 exceptions to the requirement to sell water and ditch rights under the first condition listed above: • The initial zoning of the property is ER-E, RR-E, or agricultural or the property is greater than or equal to 15,000 square feet and used for agricultural or residential use only. In such circumstances, the applicant shall offer the city first right of refusal on all water and ditch rights. This exception does not apply to Silver Lake storage water because it cannot be transferred to other properties, so the first right of refusal does not apply to holders of the right to use storage water in the Silver Lake Ditch and Reservoir Company. This exception goes on to require that when the RR-E, ER-E, or agriculturally zoned land is subdivided or redeveloped, the owner shall offer for sale to the ciry all water and ditch rights. • The person has unilaterally annexed and is offering the city first right of refusal on water and ditch rights. The two exceptions set forth in this pazagraph do not apply to Silver Lake Ditch (SLD) shazeholders because SLD shazeholders aze specifically required to offer their ditch rights to the city under the third condition above. Under the exceptions, the applicant must only offer a right of first refusal on all water and ditch rights used on or appur[enant to the property. If the zoning changes or if the land is subdivided or redeveloped, then the owner must offer the water for sale to the city at its fair mazket value. Finally, Section ll-1-19, B.R.C. 1981, also requires persons acquiring water rights after connection to the city water utility to offer such water for sale to the city. The condition under the first exception of 11-1-19(a) provides that any annexed property initially zoned as ER-E, RR-E or agricultural and greater than or equal to 15,000 square feet must sell its water or ditch rights to the city upon subdivision or redevelopment. Properties that did not transfer their ditch rights upon annexation shall transfer their rights when they subdivide or redevelop. Although it is required that Silver Lake Ditch and Reservoir Company shares be sold to the city, such owners may negotiate with the city to be allowed to sell their shazes at some later time. SLD Company shares aze singled out in the City Code because the city purchased Silver Lake and Island Lake Reservoirs from the SLD Company in 1906 with the understanding that the water associated with the purchase would eventually all become available to the city. The fair mazket value of SLD shazes is set at $25.00 per share in recognition that the city previously purchased use of the water in 1906 and only minimal market value remains with the SLD shares. Other sections of the Ciry Code cover management of the Silver Lake Watershed and protection of source water facilities. The Silver Lake Watershed has been closed to public access since the 1920's to protect this water source, which provides approximately 35 percent of the ciry's water supply. The Ciry Code supports Silver Lake Watershed closure and allows prosecution of trespassers or anyone interfering with operation of any Water Utility facilities or properties. Specifically, Title 1 l-Chapter 1(Water Utility) discusses trespass and interference with the operations of the water utiliry properties (Section 11-1-11) and prohibits activities that would contaminate or pollute the water supply (Section 11-1-12). Section 11-1-6 (Watershed Patrol Officers) requires the appointment of watershed patrol officers to "enforce city ordinances intended for the protection of the city's watershed and Lakewood properties." The watershed Source Water Master Plan Chapter 2 Page 2-27 patrol officers "have confened upon them police powers sufficient to enforce such ordinances:' In addition, Title 5-Chapters 4, 5, and 6 include ordinances regazding offenses against property, offenses against government operations, and prohibition against camping on public property. The current maximum fine that the Municipal Court can impose for trespassing violations in the Silver Lake Watershed or interference with Water Utility infrastructure or property at other locations is $1000 per occurrence. Reasons for the Silver Lake Watershed closure policy include: • Reduction of wildfire risk • Prevention of vandalism to water supply facilities • Water quality protection (both for environmental and public health reasons) • Homeland security requirements • Wildlife habitat protection ( Watershed is a known elk calving area) • Protection of lakes from contamination by non-native aquatic plants and animals and whirling disease • Protection of a fragile alpine ecosystem that is highly vulnerable to damage from uncontrolled human impacts • Protection of greenback wtthroat trout which aze a listed threatened species • Insufficient resources and staffing for the Water Utility to manage recreational activities • Possible reversion to U.S. government ownership if Silver Lake Watershed lands aze not used solely for purposes of municipal water supply as defined in original Watershed - grants 2.4.7 Contracts The city has entered into many contracts with other entities that influence how the water system operates. Boulder has contracts to deliver water for insheam flow purposes and to the SLD Company for irrigation use. Water from the CBT and the Windy Gap Projects is delivered to the city under wntracts with the Northem Colorado Water Consecvancy District (NCWCD). A conVact with NCWCD also govems how Boulder Reservoir is operated. In addition, the city sells power from its hydropower plants to Xcel Energy based on several contracts. The city also enters into an~ual contracts to lease water that is not needed for municipal use to local agricultural users. 2.4.7.1 Colorado Water Conservation Board The ciry of Boulder, in wnjunction with the Colorado Water Conservation Boazd (CWCB), has developed a program for the maintenance of streamflow within Boulder Creek and its tributaries. The instream flow program preserves fish habitat and enhances the aesthetics of the stream corridor. The instream flow program is based on dedication of the use of certain senior water rights owned by the city to the CWCB and commitments by the city to releases of water from the city's storage reservoirs. Most of these rights were derived from shares in agricultural ditch companies, which divert from Boulder Creek. Boulder had previously changed most of these shares to municipal uses through Water Court proceedings and had previously depended on this water to meet municipal water supply needs. In July 1990, an agreement was completed between Boulder and the CWCB. This agreement was amended twice, in 1990 and in 1992. This agreement and the amendments provide for the deeding to the CWCB of the right to use a podion of the city's water and water rights for instream Source Water Master Plan Chapter 2 Page 2-28 flow purposes. The city retains title to the water rights and pays annual assessments to the original ditch companies associated with the shares. The city owns the rights to use the water for municipal purposes and for leasing to agricultural users downstream of 75`" Street The CWCB owns the right to use the water for instream flow. The water is used for insVeam flows on North Boulder Creek beginning be(ow the ciry's Silver Lake Pipeline diversion, neaz the Continental Divide, continuing to main Boulder Creek below the confluence with North Boulder Creek, and down to the 75th Street bridge. The agreement also provides for Boulder to release water that is stored by the city in the Silver Lake Watershed or in Bazker Meadow Reservoir for fulfillment of the C WCB's junior 15 cfs instream flow right on Boulder Creek and the C WCB's new instream flow filings on North Boulder Creek and Boulder Creek. During severe droughts (as occurred in 2002) or emergencies, Boulder is allowed to call the water rights back and curtail storage releases for use within the water supply system. This will protect reservoir levels in the Silver Lake Watershed to preserve the native species of fish in the reservoirs. The city is also allowed to use the rights if they aze not needed to satisfy the minimum streamflow requirements at the time. 2.4J.2 Northern Colorado Water Conservancy District Since joining the NCWCD in 1953, the city has signed several operating agreements with NCWCD. Those agreements are summarized below. Annexation Agreement - August 24, 1953 The original size of Boulder Reservoir was to be 11,700 acre-feet, with one-third of the capacity reserved for NCWCD and two-thirds reserved for Bouldec The 1953 annexation agreement specifies operating conditions that were modified in the Mazch 14, 1975 agreement (see below). The annexation agreement emphasizes that the primary use of Boulder Reservoir is water supply. Recreation in the reservoir is allowed but is subordinate at all times to water supply. Supplemental Agreement - February 6, 1954 The final design for Boulder Reservoir increased the reservoir capacity from the original design of 11,700 acre-feet to 13,100 acre-feet with an operating capacity of 12,000 acre-feet. The capacity of the reservoir was enlazged to ensure flood control protection for downstream properties on Dty Creek and to increase utility of the structure. The operating capacity available to NC WCD from May 1- Oct 31 is 4800 acre-feet. The portion of the reservoir allocated for flood control from May 1- Oct 31 is 7000 acre-feet. The portion of the reservoir allocated for Boulder's long-term storage is 1000 acre-feet. An outlet canal and appurtenant structures were constructed to further increase reservoir secucity and utiliry. The outlet canal is 3000 feet in length extending from the termination of the main outlet to the beginning of a siphon neaz Dry Creek and has a capacity of 200 cfs. Boulder and NCWCD shared in the cost of the outlet canal featuxes. Second supplemental agreement - May 14, 1965 The 1965 agreeme~t defined land azea boundazies and which entity (the city or NCWCD) has control of those lands and associated facilities. The definitions are reiterated in the March 14, ] 975 agreement (see below). Source Water Master Plan Chapter 2 Page 2-29 Fitter Plant Operating Agreement - May 9, 1969 Boulder will finacice and construct the infrastructure necessary to convey water from Boulder Feeder Canal and from the reservoir to the water treatment facilities. Boulder will install measuring devices in the conveyance lines to produce a continuous record of flow to the water heatment facility. NCWCD will deliver Boulder's contracted water allotment either to the water treatment facility intake structures or to Boulder Creek. The delivery of water is limited to 90 cfs when necessary to prevent impairment of water delivery to other NCWCD allottees. Obligations of NCWCD and City of Boulder- March 14, 1975 The intent and purpose of this agreement is to provide the terms and conditions under which the respective rights and obligations ofNCWCD and the city to construction, operation, maintena~ce, modification, and management of the reservoir and appuRenant facilities will be fulf Iled. The city retains title to Boulder Reservoic The city shall design and construct a new spillway at its own expense. The District at its own cost shall control, operate, maintain, and keep in repair the reservoir in a macmer for the benefit of all its allottees. The District will pay to the city for the use of the reservoir $371,561, an amount equal to one-third the original capital cost of the reservoir. The District has exclusive and sole control of the use, occupancy, operation, and maintenance of the following land areas which comprise portions of or aze adjacent to Boulder Reservoir. • Tract A: 60 foot buffer along the Boulder Feeder Canal inlet azea. • Tract B: Pazcel of land bordered on the east by the North-South Counry Road, on the west by the North Dam of Boulder Reservoir, on the south by the access road immediately south of Boulder Creek Supply Canal, on the north by the access road immediately north of Boulder Reservoir. • Tract C: Pazcel of land within Boulder Reservoir that lies below the high water mark (or below elevation 5183.0 ft.). The District has exclusive and sole control of the use, operation, and maintenance of the following structures and facilities that aze appurtenances of Boulder Reservoir: • Chute structure at the terminus of Boulder Feeder Canal. • NoRh Dam, spillway, and outlet works. • South Dam and auxiliary outlet works. • Boulder Creek Supply Canal from the outlet works in the North Dam to inlet of the siphon. • All maintenance and access roads located on, over or adjacent to the structures described in numbers 1-4 of this list and on, over, or across lands described in Tracts A and B. • Fences, gates, cattle guazds, drainage structures, or other facilities necessary and convenient to the District in the dischazge of it responsibilities and which aze or may be located on, over, or adjacent to the facilities described in numbers 1-5 of this list. Source Water Master Pian Chapter 2 Page 230 The city has exclusive and sole control of the use, occupancy, operation, and maintenance of all lands owned by the city which comprise portions of or are adjacent to Boulder Reservoir except Tracts A, B and C. The city has exclusive and sole control of the installation, use, operation, and maintenance of the following facilities: • All buildings and structures that aze located on the lands owned by the city. • All roads, fences, gates, cattle guazds, drainage structures, pazking azeas, or other facilities necessary and convenient for recreational or other uses made by the city of lands owned by the city. • The auxiliary outlet works in the South Dam. • The tumout installed by the city in the inlet portion of Boulder Creek Supply Canal and the pipeline from turnout to the filter plant. Vehicular access by the general public on all District maintenance and access roads is not permitted. However, public pedestrian traffic over the North Dam is allowed. The ciry may utilize the land in Tract C below elevation 5183.0 ft for municipal, recreational, or other water supply purposes. All recreational use at the reservoir is subordinate to the primary use of the reservoic fot watec supply pucposes. The city has the right to construct, maintain and use a water treatment facility in Tract B, over which it retains sole and exclusive control. In addition, the ciry retains the right to e~lazge the capacity of Boulder Reservoir at its own cost and such additional capacity will be operated by the District as directed by the ciTy. Boulder Reservoir is operated by NCWCD for municipal and irrigation water storage. The reservoir was constructed to a total capacity of 13,100 acre-feet. Refer to Figure zx for an allocation of storage space between the ciTy and the District. Three hundred acre-feet below the invert of the auxiliary outlet (elevatioa 5153.5 fr.) is unavailable for use by either party. One thousand acre-feet of capacity between the imert of the auxiliary outlet and the main outlet (elevation 5159.0 fr.) is available to the city for long-term storage. A capacity of 11,800 acre-feet lies between the invert bf the maio outlet and the spillway crest (elevation 5183.0 ft.) and is available for use by both the city and the District. The District will deliver the city's conrtacted water allotment either to the water treatrnent facility intake structures or to Boulder Creek. The delivery of water is limited to 90 cfs when necessary to prevent impairment of water delivery to other District albttees. Amendedagreement-Augustl0, 1979 The poRion of the reservoir capacity allocated for flood control is decreased from 7000 acre-feet to 3900 acre-feet. Agreement between NCWCD and City of Boulder in Regards to Left Hand Ditch Company - November 17, 1992 Lefr Hand Ditch Company owns water rights on Left Hand Creek. In 1963, the ditch company signed an agreement with NCWCD permitting it to build a diversion structure from Left Hand Creek to Boulder Feeder Canal in order to divert Left Hand's water for cazriage into Boulder Source Water Master Plan Chapter 2 Page 2-31 Reservoir. The District delivers to Left Hand Ditch Company a percentage of the water diverted from LeR Hand Creek to the Boulder Feeder CanaL The total water deliverable during a water yeaz is determined as follows: Water diverted from Left Hand Creek to Boulder Feeder Canal acre-feet Percentage of diverted water deliverable to Left Hand Ditch Com an 500 or less 65 501 to 1000 60 1001 to 3000 50 Over 3000 45 The water diverted by Left Hand into the Boulder Feeder Canal is stored in Boulder Reservoir. Any water made available to Left Hand Ditch Company that remains undelivered as of November 1 of each year is turned over to NCWCD to become part of the CBT water supply. In 1992, the city signed an agreement with NCWCD regazding storage of Left Hand water in Boulder Reservoir. Boulder consented to Left Hand's diversions of water into the Boulder Feeder Canal and storage of that water in any available space in Boulder Reservoir. In return, each yeaz, Boulder receives 20 percent of the difference between the amount of water diverted to Boulder Feeder Canal by Left Hand and the amount of water delivered to Left Hand by the District. 2.4. 7.3 Silver Lake Ditch and Reservoir Company The city of Boulder has a contractual relationship with the Silver Lake Ditch (SLD) Company that makes the situation with this company different than with other ditch companies that do not have conhactual obligations. In 1906, the city purchased Silver Lake and Island Lake Reservoirs, the surrounding land, and the associated water storage rights, present and future, from the SLD Company, subject to cer[ain retained rights of the company for delivery of storage water by the city. Under the 1906 Agreement, the city agreed to a contractual delivery of water to the Silver Lake Ditch until such time as the ditch users obtained other water supplies or discontinued use of the stored water. The agreement provides that once any pazcel of land is no longer inigated by the Silver Lake Ditch, the city's obligation to deliver storage water to the SLD Company is reduced by a set amount. The original intent was that the contractual obligation to deliver storage water would diminish over time as land was annexed into Boulder, and eventually the city would have full use of the water. The initial agreement was modified in 1955 and 1965 to clarify this process and to provide water to replace seepage from the ditch (thus establishing sufficient flow to maintain riparian habitat along the ditch), but the original intent was not changed. Under the agreement, rights in the SLD Company cannot be sold sepazately from the land it is used on unless it is sold to the city. In 1965, the ciry agreed to maintain a minimum delivery of 200 acre-feet of storage water deliveries to the ditch so long as there was any user on the ditch. The SLD Company also owns a direct flow water right. This direct flow right will continue to be available to the ditch users even if no storage water is available. Thus, irrigation can continue under the ditch even as the storage water delivery obligation continues to be reduced under the terms of the 1906 Agreement. Source Water Master Plan Chapter 2 Page 232 The rate for purchase by the city of SLD Company shazes is set at $25 in Section I 1-1-19 of the City Code (B.R.C. 1981). Although it has been changed slightly, the city ordinance has been in effect essentially in its current form since 1978 with earlier ordinances requiring water rights donations dating back to the early 1960s. The rate for purchase of SLD Company shazes was set at a minimal level of $25 because the city paid the SLD Company in 1906 for Silver Lake, Island Lake and "all water rights, storage rights, water decrees, reservoir decrees, and filings, and filings for further storage of water and all other rights of every kind and nature whatsoever...owned by [the Ditch Company].". Because under the city/ SLD Company agreements the SLD Company cannot enter into any ~ew obligations to have water delivered by the company to ditch users, shareholder rights to water delivery cannot be sold separately from the land it is used on unless it is sold to the city. Therefore, no other outside mazket for SLD Company rights is allowed and company shares have no mazket value. The right of Silver Lake Ditch users to have water delivered is different than rights in other mutual ditch companies because the SLD Company started out as a contract carrier ditch company. The contractual right to use water is different than ownership of a water right. The original owner of the SLD Company kept ownership of all company assets with the company and entered into contracts with individual water users to deliver them water. Contract water users have a right to use water without having ownership of the water right that provides the water. Individual Silver Lake Ditch users have a right to use the SLD Company's water on a specific property through their relationship with the company. The SLD Company owns a direct flow water right and a holds a contractual right with the city that requires the city to deliver storage water to the company. Shazeholders in the SLD Company have a right to have the company deliver water to them based on their own individual contractual relationship with the company, but have no individual contract for water delivery with the city. The ciry's agreements with the SLD Company define the city's contractual obligation to deliver water to the headgate of the Silver Lake Ditch on an annual basis. The agreements aze summazized below. Agreement-January15, 1906 In January 1906, the ciry of Boulder purchased from the Siber Lake Ditch and Reservoir Company, through its owner, James P. Maacwell, the Silver Lake and Island Lake reservoirs, the land surrounding the reservoirs in the Silver Lake drainage basin, and all their present and future water rights. The SLD Company reserved the right to use an amount of water equal to the volume stored by the city in the reservoir space defined as lying between two elevations in Silver Lake and two elevations in [sland Lake. In 1906 when the contract was signed, no decreed storage rights, giving a court-decreed right to divert and store a quantiry of water when in priority, existed on Boulder Creek. The first reservoir storage rights in the Boulder Creek basin, including for Silver Lake and Island Lake, were decreed in a general adjudication in March 1907. Therefore, all references to the right of storing, the right to store, and storage rights reserved by the SLD Company in the 1906 contract mean the right ro have water physically placed by the city in a defined volume of reservoir storage capaciTy for the benefit of the SLD Company, not ownership of a water right. Storage water delivered to the SLD Company from the city's reservoirs was to be used for irrigation on 1006 1/30 acres of land on Mapleton Hill and north of what was then Boulder's city Source Water Master Plan Chapter 2 Page 2-33 limit. The city and the ditch company recognized the probabiliry that the 1006 1/30 acres would be annexed to the city. At that time, the SLD Company was a carrier ditch company, not a mutual ditch company which means the company did not have shareholders, but rather had a contractual relationship with water users. The assets of the ditch company remained in company ownership and the contract water users did not have any rights of ownership like shareholders in a mutual ditch company do. Through the agreement, the SLD Company stated it would not enter into any additional delivery contracts. The SLD Company contract water users were not entitled to sell their right to have water deliveced to any other water user on othet property. Therefore, there is no market for SLD Company ditch use tights. The agreement provided that, as the SLD Company's obligation to deliver water under existing contracts diminished due to abandonment of contract rights, nonpayment of assessments, or non-use, the storage water available to the SLD Company from the city's reservoirs would decrease by that amount and would become fully available to the city. The agreement recognized that no further transfer or conveyance of title would be required for the city to use any of the storage water ~o longer used by the SLD Company. No additional transfer or conveyance, such as the signing of any new deeds relinquishing ownership of water storage rights by the SLD Company, was required because the 1906 Agreement gave ownership of all interests associated with Silver Lake and Island Lake Reservoirs to the city with the SLD Company retaining only a specific right to use of a defined portion of the city's storage water assets. Supplemental Agreemenf - July 20, 1955 The 1955 Supplemental Agreement modified the original agreement by defining a formula that determines the volume of storage water to be delivered to the SLD Company by the ciry. This agreement ended any reference to the amount of water to which the SLD Company was entitled as being equal to the volume between certain planes in Silver Lake and Island Lake Reservoir and ended any remaining connection between water physically located in the two reservoirs and the required deliveries by the ciTy to the SLD Company. Instead, the ciry was obligated to deliver up to 800 acre-feet of water from any water source available to the city and that amount would decline according to a formula as land irrigated by the Silver Lake Ditch declined. The city had acquired storage rights and additional storage reservoirs for its municipal water system since 1906, and the SLD Company gained more security for its contractual storage deliveries if they were defined as a specific annual amount to come from anywhere in the ciTy's reservoir system rather than as equal to an amount that the city was able to store each yeaz in specific space in Silver Lake and Island Lake Reservoirs. Paragraph 1 of the 1955 Supplemental Agreement siates, "The original capacity in Silver Lake and Island Lake referred to in the original agreement was 951 acre feet of water." This statement does not refer to the entire original capacity of the reservoirs. Instead, it refers only to the portion of the Silver Lake and Island Lake storage space that was to be used by the city under the terms of the original agreement to make contractual water deliveries to the SLD Company. At the time of the 1906 agreement, the total capacity of the two reservoirs when full (at 16 feet for Silver Lake and ] 0 feet for Island Lake) was 1180 acre-feet. The 1906 agreement ailowed the SLD Company to have use of a volume of water that could be held in Silver Lake between the original outlet and 14 feet higher plus the volume between the Island Lake outlet and 9 feet higher. This volume was later measured to be 951 acre-feet. Therefore, in 1906, the SLD Company had initially been entitled to use 81 percent of the storage water annually diveRed by the city with that Source Water Master Plan Chapter 2 Page 2-34 amount to decline over time. The city initially had use of 19 percent of the storage water annually available from its two reservoirs. In 1887, Silver Lake Reservoir was constructed by placing a dam at a natural lake so that water could be stored and released from the space located between the outlet pipe and an elevation 16 feet higher. In 189Q Island Lake was constructed so that water could be stored and released from the space located between its outlet pipe and an elevation 10 feet highec In the1906 city/SLD Company agreement, the SLD Company did not retain the right to an amount of storage water delivery equal to everything that could be held in the two reservoirs. The company retained the right to use an amount of water equal to that amount stored by the city in Silver Lake Reservoir in the space between the bottom of the original outlet and an elevation 14 feet higher (not 16 feet higher) and to use of a~ amount of water equal to that stored in Island Lake between the bottom of its outlet and the elevation 9 feet higher (not 10 feet higher). In 1907 after the city purchased the two reservoirs, the Court, in Case No. 4842, issued decrees for the first water storage rights in the Boulder Creek basin. The Court found that the estimated capacity in Island Lake between the outlet and ] 0 feet above was 371.82 acre-feet. In 1928, the city made more reservoir storage space available in Silver Lake by putting in a new ouUet that was 15 feet lower than the original outlet. In 1953 in Civil Action 12111, the Court found that the capaciry in Silver Lake between the original ouUet and 16 feet higher was 807.26 acre-feet, and, beneath that space, the capacity between the city's new lower outlet and the original outlet was 322.7 acre-feet, giving a total original capacity for the two reservoirs of 1180 acre-feet (80726 +371.82). The 1955 Supplemental Agreement recognized that the SLD Company had originally been entitled to only an amount of storage water delivery that was equal to part of the volume that could be stored in Silver Lake and Island Lake Reservoirs by stating that the amount of water referred to in the original agreement that the SLD Company was entiUed to have the use of was 951 acre-feet. This was equal to the volume of water which the city could hold in Silver Lake between the original ouUet and 14 feet higher plus the volume between the Island Lake outlet and 9 feet higher acre-feet). Following the 1955 decoupling of the SLD Company agreement from a connection to physical storage space in Silver Lake and Island Lake Reservoirs, the ciry is now contractually obligated to provide the SLD Company with a ma7cimum of 2 acre-feet of water from any ciry source for every irrigated acre under the Silver Lake Ditch. If the city is not allowed by the state water commissioner to divert enough water under the city's 1887 Silver Lake and 1890 Island Lake water rights to fully equal the acreage formula amount to be delivered to the SLD Company from the city's water sources, then the contractual delivery amount is reduced to equal the city's actual yield from the two water rights. The water for Silver Lake Ditch is almost always delivered out of Barker and Boulder Reservoirs. The 1955 Agreement provides that: "The City shall have the right at all times to substitute other water for release of stored water for the use of the Ditch Company from Island Lake and Silver Lake Reservoirs..." The SLD Company is entitled to use and the city will deliver to the company each year an amount of water from the city's water supplies that is the lesser of the following: 1. 800 acre-feet if the area irrigated with water supplied by the SLD Company exceeds or equals 400 acres. 2. If the irrigated area is less than 400 acres, the 800 acre-feet will be reduced by an amount equal to 1.5 times the deficiency in acreage below 400 acres (i.e. for every acre Source Water Master Plan Chapter 2 Page 2-35 abandoned, the amount delivered is reduced by 1.5 acre-feet). Therefore, for the last acre of land irrigated with SLD Company water, 201 acre-feet of water will be delivered. 3. Of the amount of water that the city has stored under its 1887 Silver Lake and 1890 Island Lake water rights "in any yeaz, the Ditch Company shall be entitled to use, and the City upon notice from constituted state authority shall release for its use in such yeaz" an amount of water not to exceed the city's yield on these water rights. The ditch company may accumulate credit for water from year to yeaz but the maximum amount of storage water to be delivered by the ciry may not exceed the annual conhactual volume. The city will sell to the SLD Company an amount of surplus water the city may have that is equal to the difference between the maacimum amount allowed to the company by the acreage formula and what the ciry was able to divert under its 1887 Silver Lake and 1890 Island Lake storage rights. The price of this water is to be established by the city and is not to exceed 400 acre-feet. The city may sell the use of an additiona1200 acre-feet per year to the company. The SLD Company will not carry water in the Silver Lake Ditch for any other person or entity if transportation of such water adversely effects the city's abiliTy to transfer and exchange water received by the city from any source, excluding contracts entered into by the SLD Company prior to 1954. Since the contractual water delivery obligation is no longer tied to the amount of storage space between two planes in the city's reservoirs, the SLD Company cannot prevent the city from making alteratioas to Silver Lake or Island Lake ouUets. Agreement-June 12, 1965 In 1964, the city determined that the Silvet Lake Ditch and Reservoir Company Boazd of Directors had been approving the traasfer of SLD Company water from properties that were no longer being irrigated by the ditch to new property owners under the ditch that would be willing to use the water. These actions violated the terms of the previous agreements between the SLD Company and the ciry because the SLD Company was prohibited from entering into any new water delivery contracts. After trying to tesolve the issue with the ditch compaciy, the ciry asked the couRs to stop the SLD Company from transferting water to new land. The Silver Lake Ditch Water Users Association met, threw out the old board, appointed a new boazd, and signed the 1965 Agreement with the city. The 1965 agreement clazifies the conditions by which the amount of storage water to be delivered to the ditch company under its contract with the city is reduced. The 1965 Agreement identified specific parcels of land that were presently irrigated with water from the Silver Lake Ditch. Only those pazcels may be irrigated with the contractual water delivered under the previous agreements. This water may ~ot be transferred to other pazcels of land. After a compromise was reached in 1965, the ciry agreed to recognize that at least 400 acres were entitled to be irrigated, so the ma7cimum amount of storage water delivered by the city at that time under the agreements was 800 acre-feet annually. In 2007, there aze active contracts for water delivery to 248 acres under the Silver Lake Ditch. The new agreement provides that right of individual properties to receive deliveries of storage water under the contractual obligation between the city and the SLD Company terminates when any one of the following four conditions occur: 1. A written statement of intent to abandon, properly executed by the owner of the proper[y 2. Failure by the water user to pay an assessment when the payment is 5 yeazs overdue 3. No use of water upon the individual proper[y for a consecutive period of l years during which no assessments have been paid for the most recent 2 years out of the 7 years Source Water Master Plan Chapter 2 Page 2-36 4. A gifr or other assignment to the city by the property owner. The water donation requirements within the City Code fail under the fouRh condition above. Each yeaz, the SLD Company is required to furnish the city with a list of land on which water was used during the previous year and a list of lands upon which an assessment is in arreazs. Included with such information will be changes in ownership and any subdivision or grouping of sepazate parcels to the extent reflected in the SLD Company records. The SLD Company has taken issue with the city's position that the city bought the land and all water and storage rights associated with Silver Lake and Island Lake Reservoirs in 1906. A review of the specific language in the following documents suppoRS the city's position that the documents grant all ownership rights to the city. Based on the documents, at present, the city has a conVactual obligation to deliver to the Silver Lake Ditch an amount of water calculated based on a formula from any source available to the ciry. 1. 1906 Deed. In the 1906 deed, SLD Company deeded to the city "certain lands, water rights, reservoir sites, etc: ' in exchange for the sum of $34,000 ($698,000 in 2006 dollars). The deed conveys from SLD Company to the city "all water rights, storage rights, water decrees, reservoir decrees, and filings, and filings for further storage of water and all other righu of every kind and nature whatsoever...owned by [SLD Company]" Within the deed, SLD Company reserved the "right and privilege of storing" water in a defined portion of the city's reservoir storage space for later delivery by the city. 2. 1906 Contract This agreement, dated January 31, 1906, defines the parameters of SLD Company's storage of water in the city's newly-purchased reservoirs The 1906 contract provided that as the SLD Company's "obligation" to deliver water to its contract water users "shall be diminished", the right of the SLD Company "to store water" in the defined space in the city's reservoirs would diminish to the same extent. It also states that "the storage ~ights, priorities and decrees, and any other rights, in connection therewith, not herein specified, theretofore USED [emphasis added] by" the SLD Company "shall, ipso facto, without any transfer or conveyance become available td' the city. Use of the term "used" by the SLD Company instead of "owned" by the SLD Company in wnjunction with the recognition that no additional conveyance or transfer to the city was required for the ciry to control the water is indicative of the ownership structure contemplated by the parties. SLD Company's contractual right to have water delivered from the city's water system under certain conditions was not changed or altered in any way in 1947 when the SLD Company assets, including the 1906 Contract, were transferred from the then owner of SLD Company to the new owners of the company after the Silver Lake Ditch users bought the SLD Company. The city's obligation to SLD Company continues to be a contractual obligation to deliver a set amount of water. 3. 1955 Supplemental Agreement. This agreement modifies the city's obligation to deliver water to SLD by clazifying that the ciTy could meet its contractual obligation to deliver this water from any source available to the city. The agreement established that the ciry's obligation to supply water was reduced from the obligation of 951 acre-feet contained in the 1906 Agreement to a requirement to deliver up to 800 acre-feet of water Source Water Master Plan Chapter 2 Page 2-37 from any water source available to the city. That amount would decline as land inigated by the Silver Lake Ditch declined. 4. 1965 Agreement. This agreement identifies the specific pazcels under the Silver Lake Ditch that aze eligible for receipt of storage water and clazifies the mea~s by which SLD Company's contractual right to receive a set amount of water is reduced. 5. Court ruling in Civil Action 121 ll. The ciTy's position that the teservoir and all its water rights aze owned by the city is also upheld by this couR ruling dated September 28, 1953. The court's findings regarding Silver Lake Reservoir are that the "owner is the city of Boulder" and that "the use of said reservoir by the said ciTy is subject to a declining storage interest therein of the Silver Lake Ditch & Reservoir Company." The modifications that were made to the 1906 Contract with the 1955 and 1965 Agreements aze in line with the understanding expressed in the 1953 court decree. In addition, the city's historical practice of supplying the Silver Lake Ditch with water owned by the city that is either from CBT water exchanged up the creek or released from Bazker Reservoir, rather than directly from Silver Lake, has historically been acquiesced to by the SLD Company and is in line with this court decree. All this confirtns that the ciry's obligation to SLD Company is based on a conhacmal duty by the city to deliver water rather than any direct ownership by the SLD Company of water, water rights or any other ownership interest in Silver Lake or Island Lake. 2.4.7.4 Boulder and White Rock Ditch Agreement The city and the Boulder and White Rocks Ditch Company have an agreement for an "intemal exchange". The Boulder and White Rocks Ditch (B& WR) Company diverts less water than it is entitled to take at its Boulder Creek diversion structure and Boulder increases its diversions at its upper Boulder Creek intakes. The ciry then pays the ditch company back with an equal amount of the city's CBT water supplies delivered into the B& WR Ditch from Boulder Reservoic The city's right to do the intemal exchange is based on an agreement with the B& WR Ditch Company that resulted from the settlement of a dispute about whether the city's or the ditch company's exchange right on Boulder Creek was senior. After the city filed to adjudicate its first exchange right on Boulder Creek in Case No. W-7852-74, the court awazded the ciry a rig}N to exchange 250 cfs with an approp~iation date of 1954. The court also recognized that the B& WR Ditch Company had a more senior exchange right, dated 1926, but it was limited to 100 cfs and 4620 acre-feet annually. Due to the limitation on the B& WR exchange and the B& WR Ditch Company desire to take advantage of the city's storage space in Boulder Reservoir, and, for the city, the potential advantage of reducing the B& WR exchange needs even further, the parties entered into an agreement that allowed for the internal exchange and allowed the CBT water owed to B&WR Ditch Company to be stored in Boulder Reservoir during the inigation season. The stipulated agreement was accepted by the court in 1981 in Case No. 80-SA-102. Copies ofthe exchange decree and the stipulation aze included in Appendix . 2.4.7.5 Xcel Energy Power Purchase Agreements The city is not an electric utility and therefore, it sells all hydroelectriciry to Xcel Energy on a wholesale basis. The ciry has a series of power purchase agreements with Xcel that specify the terms and conditions governing the sale of power from each faciliry to Xcel. Some agreements pertain to individual facilities, and others pertain to multiple facilities. Each agreement contains rates of payment for generation capacity and actual generation (the latter being subject to annual Source Water Master Plan Chapter 2 Page 2-38 adjustment). Some of the city's agreements are more favorable in terms of city revenues than others, owing principally to the economics of the time at which they were negotiated and pazallel agreements that the city was negotiating with Public Service Company of Colorado, Xcel's predecessor at the time. The agreements have varying expiration dates and varying terms for renewal at the city's discretion, and therefore are subject to renegotiation at different times. Specific requirements and details of the individual agreements affect the operation of the individual hydroelectric plants as the city balances goals of maximizing hydropower revenues while maintaining electricity generation as a by-product of municipal water supply operation. 2.4.7.6 Platte River Endangered Species Recovery Agreement In 2006, the states of Colorado, Nebraska and Wyoming and the U.S. Department of the Interior completed an agreement to implement a basin-wide recovery program for several species of endangered birds and one endangered fish that rely on habitat in the Platte River Basin in Nebraska. The recovery program was developed to address the need for a coordinated approach to resolving problems faced by water users seeking any type of federal permitting. The USFWS had issued the opinion that any depletion of water flowing in the Piatte River Basin and its tributaries jeopardized the endangered species. Prior to establishment of the recovery program, individual water users had been asked to replace all depletions to the South Platte River with a like amount of water. Water users had found it difficult or impossible to meet the USFWS requirements on an individual basis. In 1994, USFWS issued a biological opinion for the Boulder Canyon hydroelectric facilities, the Lakewood Pipeline and for the facilities owned by the other cities. The USFWS found that water depletions from projects in Colorado caused deterioration of habitat for several endangered species on the Platte River in Nebraska. These included three birds (the whooping crane, the interior least tem, and the piping plover) and a fish (the pallid sturgeon). The USFWS opinion concluded that the water projecu caused "jeopazdy" to the species and that the "reasonable and prudent alternative" to address the jeopazdy was to replace all water depletions to the South Platte River on a one-for-one basis at the Colorado-Nebraska state line. The biological opinion led to negotiations that resulted in an agreement in 1997 to develop a species recovery program. The agreement was signed by the U.S. Deparpnent of Interior (which includes USFWS) and the governors of Colorado, Nebraska and Wyoming. The Platte River Recovery Program was developed, went through an Environmental Impact Study, and was put into operation in January 2007. The recovery program serves as the reasonable and prudent alternative identified in any biological opinion for a water project requiring federal authorization in the three states. The city of Boulder was contacted by the USFWS and the USFS in early 2007 about the previous biological opinion that had been issued to PSCo in 1994 for the Boulder Canyon Hydroelectric Project (the Barker system). The city had purchased the Barker system from PSCo in 2001. The USF WS stated that the prior biological opinion would only remain active if the city participated in the recovery program and joined SPWRAP. As the current owner of the Bazker facilities, the city joined SPWRAP at this time to maintain the possibility that the previously completed biological opioio~ a~d all of its associated studies can serve to meet the Section 7 compliance requirements that the city will likely face as a result of USFS authorization for the Bazker Gravity Line and the Federal Energy Regulatory Commission (FERC) re-licensing process for the Boulder Canyon Hydroelectric Project. Source Water Master Plan Chapter 2 Page 2-39 The recovery program will purchase land for habitat use by the species and will supply water that can be managed to provide peak flow periods in the Platte River that may improve habitat conditions. Scientists will monitor the effects of the recovery program so that modifications ca~ be made as needed through an approach called adaptive management. During the first 13 years of the recovery program, the goal is to reduce shortages to the USFWS tazget flows in the Platte River by 130,000 to 150,000 acre-feet per yeaz and to provide ] 0,000 acres of land in central Nebraska for habitat. Recovery program costs consist of cash and cash-equivalent contributions such as water supplies. Total costs witl be shazed with a 50/50 split between the U.S. Department of the Interior and the states. Colorado's shaze of the wsts is 20 percent of the total recovery program budget. Colorado is contributing less water and more money compazed to the other states. The state of Colorado is presently completing the development of an underground water storage project in eastem Colorado, called the Tamazack Project. This project will use groundwater rechazge to change the timing of some lower South Platte River flows from periods when flows exceed what can benefit the species to times when it will enhance species habitat. During the first 13 yeazs of the recovery program, the state of Colorado and South Platte River water users will be responsible for completing the Tamazack Project at a cost of about $15 million and contributing an additional $24 million in cash or cash-equivalents for funding recovery program activities such as acquiring additional land and water, performing monitoring and research, and doing operation and maintenance activities. The South Platte Water Related Activities Program (SPWRAP) is a Colorado non-profit corporation that has been formed by Colorado water users to assist the state in fulfilling its recovery program responsibilities. These include accounting and reporting requirements, obtaining interests in facilities and land, obtaining water rights and water rechazge credits, and providing cash for recovery progtam operations and research. Both the state of Colorado and SPWRAP will have representation on the recovery program Governance Committee and its advisory groups. Membership in SPWRAP is the only means by which individual Colorado water users can participate in the recovery program. Participation provides the benefit of certainty of Endangered Species Act (ESA) compliance for a participanYs water project and avoids individual mitigation requirements as a result of an ESA Section 7 consultation. Membership payments in SPWRAP for municipalities aze calculated using a formula based on the number of water taps served as converted into single-family residential tap equivalents. The city of Boulder's annual payment for 2007 is $71,000. Payments in future years are likely to be similaz if the city chooses to continue as a recovery program participant. Water users who do not become members of SPWRAP at this time will be required to pay SPWRAP assessmenu for all prior yeazs when they join later due to any future ESA Section 7 consultations they may face. 2.4.7.7 Agricultural and Other Leases The city leases raw water on an annual basis to support irrigation or, on a limited basis, augmentation or other uses. The amount of water available for lease is generally determined each year by the end of June and is based on the sufficiency of each yeaz's water supply to meet the city's municipal water needs. The majority of the water leased by the ciry is from the ciry's annual CBT allotment. The ciry also leases water derived from shazes it owns in the Lefr Hand Ditch and Reservoir Company, Base Line Land and Reservoir Company, the Anderson Ditch Source Water Master Plan Chapter 2 Page 2-40 Company, and the Silver Lake Ditch and Reservoir. For lessees desiring fully-consumable water, the ciry may lease effluent derived from the city's use of its Windy Gap Project units or the leasable poRion of instream flow water. The city razely enters into long-term leases, but would most Iikely consider doing so for leases of Windy Gap effluent. 2.5 Summary of Available Information and Related Studies Much information about the city's source water and raw water delivery system has been gathered over time and many studies have been completed. More detailed informatio~ on the content of many of these studies in provided in Appendix A. 2.5.1 1988 Raw Water Master Plan The 1988 Raw Water Master Plan recommended improved management of the city's water holdings and some capital projects. A few of the key recommendations and subsequent actions aze as follows: Exercise water rights and agreements to meet increasing municipal demands. The city has: • Marimized exchange yields, including exchanges with the Boulder and White Rock Ditch and Boulder Left Hand Ditch systems for purposes of drought protection and maximizing water available to Betasso Water Treatment Facility to minimize cost of water treatment and delivery. • Maintains a storage reserve in the upper Boulder Creek reservoirs • Extended the operation of the Boulder Reservoir Water Treatment Facility to a yeaz- round basis. • Acquired the Bazker water system. • Purchased shazes in ditch companies and completed water court cases to allow municipal use. • Continued to retire Silver Lake Ditch Company acres to implement intent o£ 1906 Agreement. 2. Achieve instream flow goals for Boulder Creek and its tributaries. The city has: • Implemented an i~stream flow program in conjunction with the Colorado Water Conservation Board for North Boulder Creek and main Boulder Creek based on agreements entered into in 1990 and 1992. • Applied for and received a joint city/CWCB Water Court decree allowing instream flow use of the water rights donated for this purpose by the city. • Successfully operated the insueam flow program since 1993 when the Water Court approved the decree. • Maintained minimum flow levels in Middle Boulder Creek below Bazker Reservoir since city purchase in 2001. • Obtained an agreement with the Demer Water Boazd allowing use of storage space in Gtoss Reservoir for storage of watex to be released for instream flows in South Bouider Creek. 3. Maintain, repair and replace raw water transmission pipelines and storage reservoirs. The city has: Source Water Master Plan Chapter 2 Page 2-41 • Reconstructed Silver Lake Pipeline. • Reconstructed Lakewood Pipeline. • Repaired sections and siphons on Bazker Graviry Line. • Initiated development of the Carter Lake Pipeline to Boulder Reservoir. • Maintained dams in the Silver Lake Watershed. • Rebuilt Lakewood Reservoir dams. • Increased storage at Goose Lake through repairs to the dam. • Completed preliminary design of repairs to the dam at Green Lake No. 2. 4. Establish a water conservation office. A water conservation program was implemented in 1992. The city successfully postponed the construction of additional water treatment facilities unti12004 through the water conservation program. 5. Develop a drought recognition and response plan. Ciry Council adopted reliability aiteria for the raw water system in 1989 that specify acceptable levels of frequency and amount of reduction in water availability due to drought. A Drought Plan was presented to City Council in 2003. 6. Pursue the sale of Windy Gap supplies and with proceeds from the sale of Windy Gap supplies, develop insurance against hydrologic drought. The city sold 43 of its 80 Windy Gap units to the city of Broomfield in 1991. Proceeds of the sale were used to buy the Bazker System and other water rights. 7. Develop hydroelechic potential in the water system. The city completed construction of the Silver Lake and Lakewood Hydro Plants and purchased the Boulder Canyon Hydro Plant. Hydroelectric genetation within the system is ma~cimized to the extent possible without interfering with the primary purpose of the water system for municipal water supply or with stream habitat conditions. 2.5.2 Treated Water Master Plan In 2000 the city revised the Treated Water Master Plan. The updated plan assessed the city's treated water system and presented a plan for future system development needs. Revisions to water quality regulations and standards, changes to Boulder's land use and zoning and completion of many improvements were considered. As a result, City Council approved continuation of a moderate water conservation program aimed at reducing the peak water demand and adopted reliability criteria for delivery of treated water:. Also, the Water Utiliry stepped up the replacement of water distribution pipes and developed a computerized hydraulic model of the water delivery system. Based on the plan, rehabilitation of the water treatment plants, including improvements to their chemical mixing, flocculation and sedimentation processes have been undertaken to optimize treatment and maintain existing treatment capacity. The plan recommendation to replace the potentially hazardous chlorine gas disinfection system at the Boulder Reservoir Water Treatment Facility was implemented. With these improvements, the existing water treatment plants are expected to meet Boulder's future quality and capacity requirements. The plan made recommendations for the water distribution system as well. Potential development in Areas I and II can be served through extension of the existing distribution system with requirements for proper water main sizing and looping. As the water distribution system Source Water Master Plan Chapter 2 Page 2-42 continues to grow, existing water mains will need to be rehabilitated or replaced. Smaller diameter water mains may need to be replaced to improve fire-flow efficiency. 2.5.3 Watershed Dams Evaluation An evaluation ofthe Silver Lake Watershed Dams in 1988 provided condition assessments for Silver Lake, Goose Lake and Albion Lake Dams. It also provided recommendations for rehabilitation of each dam to accommodate the Probable Maacimum Flood (PMF) and to conect or reduce other operation and maintenance problems. Spillway enlazgement was recommended for Silver Lake Dam, and this work was completed in 1989. At Goose Lake, modifications in 1989 included construction of an erosion resistant soil- cement downstream face to permit the existing dam to be safely oveRopped during the ma~imum design flood. A new valve house was also constructed to facilitate operation of the reservoir outlet. Additional work on Goose Lake to reduce seepage through the upstream face was completed in 2000. Recommendations for Albion Lake Dam included placement of rockfill and cast-in-place concrete on the downstream face to address erosion of the concrete dam due to freeze-thaw cycles. Albion Dam can be overtopped to safely pass the design flood. 2.5.4 Lakewood Pipeline EIS and Pipe Evaluations Lakewood Pipeline crosses Roosevelt National Forests lands managed by the U.S. Forest Service (USFS). The city initially proposed partial replacement of the aging pipeline in 1986. Land use authorization for the portions of the pipeline on USFS lands was finally obtained in December 2001 tluough issuance of a Water Conveyance Facility Easement. Preparation of an Emironmental Impact Statement (EIS) by the USFS for land use authorization of the pipeline became mired in a vaziety of issues, including the city's vested 1866 Act Right-of-Way for the pipeline, the USFS authority to impose bypass flow conditions on land use authorizations, and spiraling EIS costs. Reconstruction of Lakewood Pipeline was completed in 2004. Due to the presence of spiral manufacturing weld defects in pipe installed prior to 2003 and mortar anomalies throughout this pipe, regulaz monitoring of the interior of the Lakewood Pipeline has been undertaken. Inspections show that portions of the concrete mortar lining of the pipeline may have de-bonded from the steel pipe surface allowing corrosion of the pipe. Mortaz removal in selected locations revealed pitting and general oxidation of the steel. However, in locations where mortar has been removed, the steel cleaned of corrosion and mortaz repaired according to specification, subsequent inspection has found no corrosion. Corrosion has also been noticed beneath cracks in the pipeline mortar. While small, hairline cracks in wncrete mortar usualty "heal" over time, it is unclear at present whether these cracks are healing as expected. Detailed investigation of spiral weld deFects has suggested that crevice crack corrosion may affect non-wnforming welds over time and may ]ead to leaks in the pipeline much sooner than would be expected for pipe meeting industry specifications. The ciry received approximately $IS million in settlement of litigation related to mortar and weld defects in Phase III of the Lakewood Pipeline. The city intends to prepare a plan for continued monitoring and ultimately replacement of the Phase III pipe using the settlement funds. On May 12, 2004, the USFS issued Notice of Noncompliance for the Lakewood Pipeline easement. The letter states that "....the pipeline, as constructed, does not comply with the Source Water Master Plan Chapter 2 Page 2-43 requirements of the Easement and related documents because it does not meet the original contract specifications and construction plans as accepted by the Forest Service...... In order to resolve the unauthorized use of National Forest System Land......the Easement must be amended ...." Discussions concerning a modified easement for the Lakewood Pipeline were continuing as of 2007. 2.5.5 Barker Facility Assessments An evaluation of the Barker Graviry Line was conducted by GEI Consultants, Inc. in 2000, and pipeline maintenance and repair needs were identified. Some maintenance and repair was completed in each of the years from 2001 to 2007. In 2004, a plan specifying the anticipated monitoring and inspection of the Barker Gravity Pipeline and plans for completing maintenance and repair of the pipeline was completed. Anticipated types of scheduled maintenance are shown in Table xx. Table xx: Barker Gravity Line Maintenance and Repair Schedule Replacement of markers, vent risers and other minor appurtenances Valve repair Pipe patching and retaining wall repair Replacement of damaged pipe sections Slip lining 10-20 years 5-10 years 10-30 years ATV with trailer or pickup truck where access road allows See above Pickup truck or ATV Exposure of vault Minor temporary corridor disturbance, exposure of vaults Pickup trucks, Conidor disturbance, exposure of air heavy equipment, valve vaults and pipe at intervals helicopter along the pipeline Possible in 10-20 Pick-up trucks, Corridor disturbance, exposure of years, then every heavy equipment, pipe and appurtenances at intervals 20-40 years helicopter along the pipeline. Emergency repairs Unknown 2.5.6 Drought Plan Variety of Corridor disturbance, exposure of equipment pipeline or associated facilities depending on nature of problem The city of Boulder Drought Plan, completed on February 20, 2003, provides guidance for recognizing droughts that will affect water supply availability for the city and for responding suitably to these droughts. Volume I is the Drought Response Plan, which includes summary information on the city's water supplies, a categorization of drought levels according to severity, and detailed information on the particular actions that might be taken to respond to each drought alert level. Volume II is the Drought Technical Information and Analysis that provides the None None Yes - 90 day notification when on County or forest land Yes - 90 day notification when on County or forest land Yes - when on County or forest land as soon as practicable Source Water Master Plan Chapter 2 Page 2-44 ........ .... ...u...,,. , ..,.,~ .,,.Y.,.,,..., .~. vent repair Nnne supporting documentation for the Drought Response Plan. Specifically, Volume II contains the detailed analysis, data, and history to help assess the city's water supply system. The analysis was conducted using demographic assumptions and resulting water demand from Scenario 1 of the Jobs and Population Project memorandum dated September I 8, 2002. Scenario 1 projected a population of 140,500 people, an employment level of 164,600 jobs, and a treated water demand of 26,800 acre feet) at build-out. This levei of build-out demand assumes that the goal of a I Opercent reduction in water demand as compared to current levels will be achieved by the city's on-going water conservation program. The analysis also incorporated virgin stream records reconstructed from tree ring data for the period 1703 to 1987 and virgin stream records reconstructed from stream gages and diversion records for the period 1910 to 2002. 2.5.7 Middle Boulder Creek Water Source Management Work Plan The city developed the Middle Boulder Creek Water Source Management Work Plan after purchasing the Boulder Canyon Hydroelectric Project in Z001. The purpose of the Plan was to establish management goals and direction for the Middle Boulder Creek watershed and Barker Reservoir (GEI 2002). Existing information on the Barker system and watershed was compiled and evaluated but no new studies were conducted. The city developed several recommendations for the Barker system and Middle Boulder Creek watershed in the areas of system operations, water quality protection, recreational use of the facilities, land management, security, and facilities enhancement. 2.5.8 Water Quality Strategic Plan The city is currentfy preparing a Water Quality Strategic Plan to provide a framework for maintaining water quality and conservation standards and to help balance city priorities with regional efforts. The plan is organized into five major areas of work, each with an overarching goal, corresponding to proposed objectives and priority services: Goa! #1: Protect Public Heul!!r • Provide Safe Drinking Water • Keep Creeks, Rescrvoirs and Lakes Safe Goa! #l: Proteet Enviro~u~ie-itul Heult/r • Protect Aquatic Ecosystems • Ensure Adequate Water for Fish and Wildlife Gonl #3: Assure Reh uluturp Complirr~rce • Comply With Drinking Water Standards Goal #4: Promote Resource Couservulion • Promote Wise Watcr Use • Keep Water Clean and Minimize Pollutants Gou! #S: Promote Comm~inicnlion rurd Conperation • Increase Public Knowledge and Involvement Source Water Master Plan Chapter 2 Page 2-45 • Promote Local and Regional Cooperation 2.5.9 Boulder Reservoir Watershed Management Group Resource and Information Guide The Boulder Reservoir Watershed Management Group is composed of representatives from vazious ciry departments and agencies that have an interest in the management of the Boulder Reservoir watershed. Stakeholders include city Public Works, Pazks and Recreation, and Open Space and Mountain Parks departmenu; Boulder County Transportation, Parks and Open Space, and Public Health departments; Northem Colorado Water Conservancy District; and Colorado Division of Wildlife. The purpose of the group is to foster communication, resolution acid cooperation land management, special events, water quality and other issues within the watershed. The group began developing a Resource acid Information Guide for the watershed in 2004. The Resource and Information Guide is a working document, updated periodically as needed, containing background information deemed fundamental by stakeholders for operation and management of activities within the watershed. The purpose of the document is to provide stakeholdets a reference guide to be used when making management decisions for the watershed. The intent is to inform stakeholders how activities might impact other stakeholders or provide contact information to facilitate cooperation. 2.5.10 Water Conservation Futures Study The city established and funded a water conservation program in 1992. The water conservation program was revised and updated in 2000, when the Treated Water Master Plan and the Water Conservation Futures Study (WCF Study) were approved. The WCF Study analyzed a vaziety of conservation program options for the fuhve. The adopted plan was intended to result in a 10 percent reduction in water use at build-out (approximately 2025) when compazed to the water conservation program in-place in 2000. 2.5.11 Source Water Impact Assessment The Water Source Impact Assessment (Brown & Caldwell 1992) study was the first step in the city's source water protection program. The study includes a physical description of the raw water supply system, an overview of treated water quality and constituents of potential concern, a review of potential contaminant sources and impacts, and recommendations for actions. Constituents of potential concern in a municipal water supply are those that either pose a health threat or alter the aesthetic acceptability of the water. The constiments are of interest due to their effects on treaunent expense and on treated water qualiry. In the study, thirty-three potential sources of contaminants that could affect the city's source water were evaluated. Of the top five contaminant sources, four aze in the Boulder Reservoir water source. The North Boulder Creek watershed is susceptible to high suspended solids during spring runoff. The Boulder Feeder Canal is vulnerable to o~ganics, trihalomethane precursors, pesticides, herbicides, nitrate, phosphorous, dissolved solids, and pathogens from agricultural and feedlot runoff; to organics and hazardous materials from public access and illegal dumping; and to copper and algae from canal cleaning operations. Boulder Reservoir is susceptible to suspended solids from wind action. Source Water Master Plan Chapter 2 Page 2-46 Numerous actions were recommended for the city to include in their source water protection program. Five specific components of an action plan were recommended: routine reviews of the raw water system and potential contaminant sources, a water quality monitoring program, further investigation of suspected contaminant sources, a plan and procedures to respond to emergencies, and a program of system improvements and operations procedures. 2.5.12 Integrated Evaluation of Boulder Reservoir Water Treatment Facility Source Water Protection and Treatment Improvements While the city is wrrently meeting all regulatory requirements for drinking water standazds, the water quality in areas served by the BRWTF is vulnerable to degradation as a result of seasonal vaziation of the water quality in the Boulder Reservoir and acute contamination episodes in the Boulder Feeder Canal and the reservoir. The Integrated Evaluation of Boulder Reservoir Water Treatment Facility (BRWTF) Source Water Protection and Treatment Improvements study, completed in 2007, was recommended in two previous reports, the Source Water Quality Planning Study - Phase I(2003) and the Pre-design Reporf for Near Term Improvements for the Boulder Reservoir Water Treatment Facility (2003). The study develops and evaluates altematives for source water protection and long term improvement to treatment processes. Each altemative was evaluated based on performance, as well as total present worth cost. The addition of UV disinfection would provide adequate pathogen inactivation, but this alternative would not provide an effective barrier for organic micro-pollutants. The concern of organic micro-pollutants would be addressed with the addition of GAC. Alternatives that propose eliminating the use of the BFC would provide some potential settling of Cryptosporidium. However, water quality data from the reservoir indicates similaz, if not higher, levels of bacteria in the reservoir as the Boulder Feeder Canal. The Carter Lake Pipeline altemative meets all of the city's water quality goals and provides at least one barrier for each contaminant category evaluated. Based on consideration of both long tertn performance and cost, wnstruction of the Carter Lake Pipeline is recommended as the prefened altemative. Although the capital cost of constructing a pipeline is relatively high, the total present worth cost is compazable to other altematives. 2.5.13 Boulder Valley Comprehensive Plan The Boulder Valley Comprehensive Plan is a joint plan between the city of Boulder and Boulder County, providing shared land use decision-making in the Boulder Valley. The plan sets a course for the future growth and development of the city and the lands just outside the city's boundazies. The plan is adopted by four bodies: The city of Boulder Planning Board, the City Council, the County Planning Commission, and the Board of Counry Commissioners. The BVCP: Provides a statement of the community's desired long-term future development pattern and sets the city's land use and development policy, guiding day-to-day development review decisions. It has been one of the most impoftant tools for managing Boulder's growth. Source Water Master Chapter 2 Page 2-47 • Uses a 15-yeaz timeframe that allows present-day decisions to be made in a context of desired long-term goals. Provides for major updates every five yeazs to reflect changes in circumstances and community desires. Defines the limits for urban development in the Boulder Valley. Area I, II, and III designations establish the framework for annexation and service provision. Area I is the azea within the ciTy. Area II is the azea planned for annexation and service provision within the 15-yeaz planning period. Areas I and II form the city's Service Area. Area III-Rural Preservation Area includes lands designated to remain rural in chazacter. Area III-Planning Reserve is an area where the city and county intend to maintain the option of expanded urban development beyond the planning period. Defines the desired land use pattern regazding location, type, and intensiry of development. 2.5.14 Instream Flow Studies 2.5.15 History of Boulder's Water Utility 2.5.16 Historic Water System Evaluations 2.6 GIS Resources The ciTy of Boulder Information Resources DepaRment and the OSMP GIS group maintain GIS resources for the city. Over time, the Information Resources and OSMP have developed sepazate GIS databases. While some ofthe information is shazed, other information such as ditch alignments has been updated sepazately by each group and two £les exist. A reconciliation ofthe differences in information and merging of the databases would increase efficiency within the city. Source Water Master Plan Chapter 2 Page 2-48 ATTACHMENT C: SWMP Draft Section 3- Raw Water Supply System Assets Preliminary Draft August 12, 2007 3. RAW WATER SUPPLY SYSTEM ASSETS 3.1 Land Beginning in the 1880's, Boulder began purchasing land to support the development of its municipal water utility. Boulder acquired a site located just west ofthe town to build Sunshine Reservoir and land for an intake from Boulder Creek near the mouth of the canyon. By 1904, plans had developed for a water system fed by high-altitude watersheds free from pollution. Boulder, now a small city, made the first purchases of land along the upper reaches of North Boulder Creek near the Continental Divide in what would become the city-owned Silver Lake Watershed. In the 1950's, the city sought to expand its ability to provide water supplies in drought years by joining NCWCD and purchasing land to construct Boulder Reservoir. The Park Reservoir dam site was purchased in the 1960's. Later, the city purchased the Wittemyer Ponds in order to increase Boulder's ability to reuse the limited amount of fully- consumable water available to the city. In 2001, Barker Reservoir was acquired to increase the city's water yield from its existing water rights and to provide the city more flexibility in managing its Middle Boulder Creek water supply. The city purchased certain lands in Caribou Ranch to protect water quality along North Boulder Creek and to better manage and maintain some of the North Boulder Creek water facilities. The city's Water Utility now manages over 7000 acres of land at locations ranging from the Continental Divide west of Boulder to the eastern Boulder County line. 3.1.1 Silver Lake Waters6ed The Silver Lake Watershed is located on the eastern slope of the Continental Divide north of Nederland at the headwaters of North Boulder Creek. ln 1904, the city purchased reservoirs and water storage rights in the area that would later become the Silver Lake Watershed by acquiring the Triple Lakes and Oval Lake (which would later be raised with a dam to become Goose Lake) from Clint Maxwell, son of J.P. Maxwell.. In 1906, the city purchased land and water rights at Silver Lake and Island Lake from the Silver Lake Ditch and Reservoir Company for a sum of $34,000. A copy of the deed is included in Appendix _. The city acquired Silver Lake and lsland Lake Reservoirs, the land surrounding the reservoirs, and "all water rights, storage rights, water decrees, reservoir decrees and filings, and future filings for water storage." Figuee shows those lands acquired in the 1906 transaction. The city has signed contracts with the Silver Lake Ditch and Reservoir Company to annually deliver a certain amount of storage water to the company's headgate on Boulder Creek. Copies of the agreements between the city and the Silver Lake Ditch and Reservoir Company are summarized in Chapter 2 and are included in Appendix Following the city's initial acquisitions of land within the Silver Lake Watershed, the U.S. Congress granted the city the right to purchase additional lands within the Silver Lake Watershed pursuant to three Congressional Acts in 1907, 1919, and 1927. Copies of the Acts, Congressional records, and Congressional grants are attached in Appenclix _. The 1907 Act was passed on the same day that the surrounding land was reserved by Presidential Proclamation for the Medicine Bow National Forest. The subsequent 1919 and 1927 Acts withdrew lands from the Roosevelt National Forest, which was a part of what had been the Medicine Bow National Forest, and granted them to the city for the city's use for water supply purposes under the same provisions of the original 1907 grant. The 1907 Act granted 1,557 acres to the city, the 1919 Act granted 400 acres, and the 1927 Act granted 3,689 acres, all for the price of $1.25 per acre. Figure identifies lands with the Silver Lake Watershed that were acquired through the three Congressional Acts. Congress granted the Silver Lake Watershed to the city for purposes of water storage, supply of its waterworks, and protection of its water supply from pollution. For such purposes, the city was granted "forever...the right, in its discretion, to control and use any and all parts of the premises [t]herein Source Water Master Plan Chapter 3 Page 3-1 Preliminan Draft Au,ust 12. 2007 conveyed, and in the construction of reservoirs, laying such pipes and mains, and in making such improvements as may be necessary to utilize the water contained in any natural or constructed reservoirs upon said premises..." (Pub. L. No. 185, 34 Stat. 1223 (March 2, 1907)). The associated patents dated June 15, 1908, June 18. 1920, and July 23, 1929 expressly recognized the purposes of water supply and storage and included within the grant to the city "all the rights, privileges, immunities and appurtenances of whatsoever nature thereunto belonging, unto the said City of Boulder, and to its successors, forever." The U.S. Congress retained no federal discretionary authority over the city's operation of the watershed grants for these water supply purposes. The grants were qualified only in terms of a reversion to the United States if the grants were not used for the specified purposes and by reservations for certain preexisting claims and timber and mineral rights. Congress rejected the Department of Agriculture's position at the time that these federal grants of vested property rights were unnecessary because the city could obtain subsequent authorizations from the agency for water projects. In 1910, the city acquired land at the Albion mining camp for construction of Albion Reservoir. Over time, the city acquired additional smaller parcels of land within the Silver Lake Watershed from other entities. The total amount of land now held in the Silver Lake Watershed in about 6500 acres. 3.1.3 Park Reservoir Dam Site The Park Reservoir da~n site is located on Caribou Creek (i.e., the south branch of the south fork of North Boulder Creek) approximately 3.5 miles upstream of Lakewood Reservoir and just west of Caribou Ranch. Construction of a dam was first attempted by the private owners of the site in 1905. They did not Source Water Master Plan Chapter 3 Page 3-2 Preliminary Draft August 12, 2007 complete the dam after it was breached during a flood before construction could be completed. Dam reconstruction was proposed by the property owners in 1960, but no construction on a dam ensued. Instead, the property owners and the city began discussions of the potential for the city to use the site for a municipal water supply reservoir that would provide additional drought protection for the city. In 1970, the ciry purchased the Pazk Reservoir site through a"friendly condemnation"' of 120 acres of property for a price of $250,900. Figure _ shows the Pazk Reservoir dam site. While the ciry owns 120 acres of the dam site, the US Forest Service owns approximately 60 acres of land that would be inundated if a dam were built to impound a 3000 acre-foot reservoir at the old dam site. Therefore, the city would likely need to obtain a Special Use Permit from the Forest Service prior to construction of a dam with this configuration. However, a lower dam, a series of dams, or a dam fur[her to the east of the old dam site could be constructed that might not raise water levels sufficiently to cover USFS land. Documents related to the purchase of the Pazk Reservoir dam site and water rights aze included in Appendix _. 3.1.4 Lakewood Reservoir Site and Lakewood House The twenty acres of land where Lakewood Reservo'u is now situated was acquired by the city in 1906 from T.N. Bamsdall of Pittsburg, Pennsylvania for purposes of construct an intake resetvoit for the ' Boulder City Pipeline (now Lakewood Pipeline.) Easements for the pipeline and for diversions from North Boulder Creek and from Como Creek were also acquired. Mr. Barnsdale was given the right to construct a pipeline from North Boulder Creek that would drive a hydroelectric plant before dischazging into Lakewood Reservoic City officials were already considering the potential need to extend the Boulder Ciry Pipeline fur[her up into the Silver Lake Watershed since the city also acquired the right to connect a future pipeline from Silver Lake Reservoir into Mc Bamsdale's pipeline "should fuhue emergencies require, whether from pollution of the stream or otherwise." Mr. Barnsdale never constructed his pipeline and power plant. In 1919, the city constructed the Silver Lake Pipeline without benefit of being able to tie into Mr. Barnsdale's pipeline. The Lakewood Reservoir property is also the site of the Silver Lake Hydroelectric Project (see Section 3.2.1.8) and the Water Resources Facilities Manager's residence with gazages and outbuildings. The residence was originally constructed in the 1950sand was renovated in 1996. Silver Lake Hydro was completed in 1998. 3.1.5 Caribou Ranch Through a complex agreement in 1996 (Caribou 1) and an amendment to the agreement in 2001 (Caribou 2), the city and Boulder County jointly purchased 2,180 acres of Cazibou Ranch and associated water rights from James Guercio. A subsequent amendment to the agreement was made in 2004 to clazify provisions of the earlier agreements. The Utilities Division used revenue from the sale to the ciry of Broomfield of43 of 80 Boulder's Windy Gap uniu to fund the Caribou Ranch purchase. Through the agreements, the city acquired fee title to a 120 foot wide corridor along the Silver Lake Pipeline where it crosses the purchased Caribou Ranch acreage and Boulder CounTy received a ~ A friendly condemnation is an agreement that states that the property is being acquired by a govemment entity under threat of condemna[ion so that [he property owner can reinves[ in other property wi[hout tas consequences from the sale. Source Water Master Plan Chapter 3 Page 3-3 Preliminary Draft A~gust 12, 2007 conservation easement over this parcel. Boulder Counry obtained title to the remainder o£the purchased acreage with the city holding a conservation easement over that acreage. The County also acquired some of the water rights used for irrigating the ranch. Guercio retained ownership of about 1068 acres of Cazibou Ranch and water rights for irrigation of his retained acreage and for some ponds. In addition to the fee properties, the city and Boulder County acquired 449 acres of conservation easement over the Caribou Ranch property retained by Guercio referred to as the "buffer lands" (Figure ~. Moreover, the city acquired a perpetual easement across the poRions of Caribou Ranch retained by Guercio for construction, reconstruction, replacement, monitoring, operation, maintenance, repair and access to the Silver Lake Pipeline, the Lakewood Pipeline, North Boulder Creek diversion facilities, and related water utility facilities by the city. Negotiations for the Caribou 2 agreement included discussion of development of a pazcel of land owned by Guercio that was adjacent to Cazibou Ranch. The property, known as Caribou City, had received plat approval from Boulder Counry i~ the ]970's for development of 115 residential lots. Boulder County no longer believed that level of development was appropriate and the city was concemed about the impact of 115 septic systems located above the North Boulder Creek intake to Lakewood Reservoir. The negotiations resulted in Guercio limiting development to 23 dwelling uniu plus a fishing lodge and a non- commercial horse barn. One of the city's purposes for participating in the purchase of Caribou Ranch land and conservation easements was to gain ownership and easement rights for all of the Silver Lake Pipeline corridor and an understanding with Guercio of how the pipeline would be reconstructed. In addition, the city desired to protect the quantity and quality of the city's water supply deliveries into Lakewood Reservoir. The agreements also accomplished several other property trades such as a land trade made to cleaz up property boundazies adjacent to Lakewood Reservoir. The city of Boulder Open Space and Mountain Pazks Department (OSMP) also participated in the complicated agreement by contributing some funds that were used to purohase a 50 percent interest in the old Beech Aircraft site with Boulder County owning the other 50 percent.. In addition, the agreement provided Boulder County with a conservation easement over the Wittemyer Ponds property that would still allow the ciry to develop the site as a water storage facility. Boulder County agreed to act as the land manager for the Wittemyer Ponds property. Boulder County also acts as the land manager for the purchased Caribou Ranch lands and is required to manage the land in a manner that protects water quality ia the watershed that feeds the ciTy's municipal water system. The city signed an interruptible supply contract stating it would make 170 are-feet of water per year available to Guercio from its water supply for purposes of irzigation of certain meadow azeas only. Another 5.0 acre-feet was made available to Guercio for augmentation of certain current and future water uses associated with Guercio's property. The city may choose not to deliver the irrigation water during periods of extraordinary drought or emergency conditions as it did in 2002. Moreover, through 2021 the city agreed to lease the amount of Jasper Reservoir water offered by Guercio each year at the city's CBT lease rate. A sample lease agreement is attached in Appendix _. The city acquired Guercids interests in water rights he had initiated to develop hydropower on North Boulder Creek, Caribou Creek and on the city's Silver Lake Pipeline in Case Nos. 81 C W419 and 82C W444. The city did not want these competing hydropower righu to interfere with its hydro generation activities and so gave notice to the Water Court of an intent to abandon these hydropower water rights in 1999. The court issued orders abandoning the water rights in 2001 and 2007. Source Water Master Plan Chapter 3 Page 3-4 Preliminary Draft August12,2007 The city provided almost all of the i~itial funding for the Caribou Ranch purchase in 1996. Between 2002 and 2004, the city sold most of its Caribou Ranch fee properties and all associated water rights, except for the hydropower rights, to Boulder County. The city retained the Lakewood Reservoir parcels and the Silver Lake Pipeline parcel (land that lies 60 feet on either side of the centerline of the pipeline). The city granted to Boulder County a conservation easement over the Silver Lake Pipeline pazcel. Boulder Counry granted to the city a conservation easement over all lands transFened to Boulder County. The city and Boulder County each own a 50 percent interest in the mineral rights that were transferred with the land. Although Boulder County manages the acquired Cazibou Ranch 1 propetty, the city Water Utility has input to the property's management plan to ensure watershed and water quality protection. Utilities staff has taken an active roll in monitoring Boulder County's compliance with the management plan to ensure the specified source water protection measures aze applied. The Caribou Ranch Management Plan can be viewed at http~//www co.boulder.co.us/opensoace/manaqement plans/mgmt~lans.htm. A summary of the Caribou Ranch property cbsings between the city, county and Guercio, with information on the Cazibou Ranch proper[y transactions, conservation easements, and watet rights transfers is attached in Appendix _. In addition, it includes agreements and supporting documents that contain details on the transactions solely behveen the city and Guercio, such as use of city water by Guercio, city lease of Jasper Reservoir water from Guercio, city-Guercio exchange of property adjacent to Lakewood Reservoir, and pipeline easements A copy of the separate Bouider County/Guercio agreement is also included along with the cityBoulder County agreement.. 3.1.6 Barker System Bazker Meadow Reservoir (Bazker Reservoir) is located on Middle Boulder Creek just east of the Town of Nederland in Boulder County. In 1907, Central Colorado Power Company purchased property for a dam and reservoir site from Hannah Bazker. The acquisition was made through a condemnation, as Hannah Barker refused to sell her ranch holdings. In the summer of 1908, the Central Colorado Power Company began construction of Bazker Dam and the Boulder Canyon Hydroelectric Plant for the purpose of providing electricity to thriving mining camps and the booming city of Denvec The Boulder Canyon Hydroelectric Project (Bazker System), which includes Bazker Reservoir, Bazker Dam, the Bazker Gravity Pipeline, Kossler Reservoit, the pipeline from Kossler Reservoir to Boulder Canyon Hydroelechic Plant, and the Boulder Canyon Hydroelectric Plant, was completed in 1910. In 1987, the city initiated a public review process to evaluate the water supplies that Boulder owned and discuss options for use of the water. The studies resulted in the 1988 Raw Water Master Plan. One of the findings of the studies was that Boulder owned sufficient water supplies to meet projected municipal demands at build-out. However, Council recommended that staff attempt to reconfigure the ciry's water portfolio through sale of W indy Gap water and replacement of the water with water supplies and assets in the Boulder Creek basin that would be capable of multiple uses and would enhance the yield of existing systems. The city pursued this goal through the sale of 43 of its original 80 units in the Windy Gap Project to the city of Broomfield in 199L The city used proceeds from the sale to jointty pwchase Cazibou Ranch with Boulder County and to purchase the Bazker System from Public Service Company of Colorado (PSCo), a successor of Central Power Company. The city acquired the Barker System, associated water ri hts, easements, and rights-of-way on March 7, 2001 for a price of $12.4 million. The purchase included~ acres of lacid encompassing Barker Reservoir, Kossler Reservoir, the Boulder Canyon Penstock, and the Boulder Canyon Hydro Plant site as shown in Figure _. The Bazker Gravity Line is on easements, either deeded or prescriptive, and on land designated as a Power Withdrawal across US Forest lands. Remaining funds from the Windy Gap sale were dedicated to the repair and upgrade of the Bazker System. The purchase agreements and associated documeats between the ciry and PSCo for the Barker System are included in Appendix _. Documents Source Water Master Plan Chapter 3 Page 3-5 Preliminary Draft August 12, 2007 related to water rights, mineral rights, deeds, easement, and rights-of-way for the Barker System aze also included in Appendix _. Along with the Bazker System, the city acquired decades of records from PSCo. Most of those tecords have been catalogued and aze stored at the Betasso Hydro Plant. Other records aze contained in files stored in the Pazk Central2nd Floor library. Examples of these recocds include inspection reports, operation reports, and construction reports. A file labeled `Bazker Folders" lists those records stored at Park Central and is contained in Appendix _. 3.1.7 Water Source Operations Manager's House The city purchased a 128-acre lot and single family residence in St. Anton Highlands in 2002 as a residence for the Water Source Operations Managec This position was added as a result of the purchase of the Boulder Canyon Hydroelectric facility in 2001. In keeping with the practices of other owners of large reservoirs in the state of Colorado, the city determined it prudent to provide on-site personnel with immediate availability to the Bazker/Boulder Canyon facilities day and night. The residence was originally constructed in 1996 and a gazage/office was added in 2000. 3.1.8 Betasso Water Treatment Facility Site and Betasso Penstock Corridor 3.1.9 Orodell Hydro Plant Site (Blanchard Intake) 3.1.10 Sunshine Reservoir Site 3.1.11 Boulder Reservoir Lands Boulder Reservoir is the terminal reservoir for the southern end of the Colorado-Big Thompson (CBT) Project. The CBT Project is a trans-mountain diversion owned by the Bureau of Reclamation and operated by the Northern Colorado Water Conservancy District (NCWCD). The project was authorized in 1937 and wnstructed in the eazly 1950s. Initially, the city of Boulder opted to not join NCWCD. However, post-World War II growth convinced city officials of the need for additional water. Boulder's citizens voted to join the NCWCD in June 1953 and the contracts between the city and NCWCD were signed in August 1953. As part ofthe agceement to enter the NCWCD, Boulder agreed to pay back ta7ces and to build a new reservoir on the southern end of the CBT system. The decision was bolstered when a severe drought hit from 1954 to 1956. Several sites for the new reservoir were investigated before settling on a site at Big Dry Creek northeast of Boulder. The proposed reservoir was originally known as the Twin Lakes Reservoir before the city settled on the prosaic name of Boulder Reservoir. Water Utiliry revenue bonds were issued that provided $1.2 million for purchase ofthe necessazy land and for construction ofthe dams. The agreements with the NC WCD provided that a portion of the storage space in Boulder Reservoir would belong to the NCWCD for use as part of the CBT system. The NCWCD paid the city $450,000 for this storage space in installments over a forty yeaz period. Between 1954 and 1956, the ciry purchased the majority of the land comprising the Boulder Reservoir azea. Land for the Boulder Reservoir water treatment facility was acquired with water utility revenues in 1970. A map of land ownership in the Boulder Reservoir area is shown in Figure Source Water Master Plan Chapter 3 Page 3-6 Preliminarv Draft August 12, 2007 The city owns several properties adjacent to Boulder Reservoir purchased with General Fund monies for parks and recreation purposes. The Pauline Axelson property (71 acres located northwest ofthe reservoir) was acquired between 1971 and 1974 through funding provided by the Parks and Recreation Department and the Bureau of Outdoor Recreation. In 1983, the Kane property (5 acres located north of the reservoir) was acquired with funds from the Parks and Recreation Department and the Utilities Division (figure xx). Appendix XX contains deed and parcel information for the Boulder Reservoir area. The NCWCD operates and maintains the Boulder Reservoir dams and water conveyance facilities. The city, through its Water Utility, has the overriding management role in coordinating activities with the NCWCD, city Utilities staff, and city Parks and Recreation staff. In addition, the Water Utility is responsible for ordering its share of water from the NCWCD to be used directly at the water treatment facility or to be stored in the reservoir. It is also responsible for protecting water quality for municipal purposes. The Parks and Recreation Department has become the management entity for the recreation facilities, wildlife, weed control, and certain fencing. A series of agreements between the city and the NCWCD outline ownership and management responsibilities (Appendix X) 3.1.12 Wittemyer Ponds In 1986, the Public Works Department purchased 159 acres known as the Wittemyer Ponds property including mineral rights and water rights for $380,000. The Wittemyer Ponds properiy lies south of Highway 52 (also known as Mineral Rd.), north of Boulder Creek, west of the Boulder/Weld County Line road and east of 115~' St (Figure ~. Prior to acquisition by the city, 68 acres of the property had been mined for gravel. The gravel pits have since filled with groundwater, creating a series of five ponds on the property. The gravel mining occurred prior to 1969, so the ponds are considered to be "grandfathered" under Colorado State Statutes from requirements to augment surface evaporation of the exposed groundwater. The city purchased the Wittemyer Ponds property with the intention of lining the gravel pits and using them to store reusable water for later exchange into the city system or lease to downstream water users. The pits will need extensive work before they can be lined and used for water storage. To date, the city has not included funds in the Capital Improvement Program budget to line the gravel pits. Through an arrangement formalized in the 1996 Caribou Ranch property transaction, Boulder County manages the Wittemyer Ponds property for the city. The city granted Boulder County a conservation easement over the property. The conservation easement establishes that the Wittemyer Ponds properly shall be used in perpetuity for city Water Utility purposes. No other development may occur on the property except that the conservation easement will expire and the city may sell the property for development if the County denies a city ] 041 application for improvements to the ponds needed for city Water Utility use. The conservation easement agreement provides that Boulder County will manage the property for the city in a manner which does not interfere with the use of the property for Water Utiliry purposes. The history of the W ittemyer Ponds property since being acquired by the city and details about the property management arrangement are included in Appendix _. 3.2 Municipal Water Supply Infrastructure The city's obtains its municipal water supply from three sources. At present, approximately 35 percent of the city's annual water supply originates in the North Boulder Creek basin above Lakewood Reservoir Source Water Master Plan Chapter 3 Page 3-7 Preliminan~ Draft .~u~ust 12. 2007 and the city-owned Silver Lake Watershed. Another 3~ percent, on average, is diverted from Middle Boulder Creek, some of which is stared in Barker Reservoir. "I~he balance is supplied by Boulder Reservoir sources including the Colorado - Big Thompson (CB'I') and Windy Gap projects. The infrastructure associated with each of the three water sources are discussed in sequence from hibhest to lowest elevation, below. 3.2.1 North Boulder Creek Water Facilities In 1904, the city made its first agreements to purchase reservoirs and water storage rights in the area that would later become the Silver Lake Watershed by acquiring the Triple Lakes and Oval Lake (which would later be raised with a dam to become Goose Lake) from Clint Maxwell, son of J.P. Maxwell. Most of the land in the Silver Lake Watershed was deeded to the city of Boulder by the US Congress specifically for water supply purposes. The city was able to purchase this land from the federal government based on three Congressional Grants in 1907, 1919 and 1927. The Silver Lake Watershed contains 13 reservoirs and natural lakes that are fed by snowmelt. A minor amount of water is contributed by melting of the Arapaho Glacier. This high-quality water source was sufficient to meet all of Boulder's water needs until the 1950s. Facilities associated with the North Boulder Creek water source are listed in sequence from the Silver Lake Watershed lakes and reservoirs to Betasso Water'I'reatment Facility, below. Water supply facilities located in the North Boulder Creek watershed are shown on Figure Figure : Upper Boulder Creek Basin Watcr Sources ~suima~ 3.2.1.1 Gree~t Lakes Green Lakes #1, 2, 3, and 4 were purchased by the city in 193~. A private developer had constructed dams at Green Lakes # I, 2 and 3 from 1902 to 1906 to raise the natural lake levels. Grcen Lake i~5 was Source Water Master Plan Chapter 3 Page 3-8 Preliminary Draft August 12, 2007 purchased by the city in 1937. The Green Lakes along with Albion Lake occupy the northem valley of the Silver Lake Watershed. This drainage is called both the North Fork of North Boulder Creek and Albion Creek. Green Lake #1 is the city's smallest watershed reservoir with a ma~cimum operating capacity of 92 acre- feet. Its decreed volume is 175 acre-feet. Curtent operating capaciry is 88 acre-feet. Surface azea is approximately 11 acres. Green Lake #I is classified as a low-hazazd dam. Green Lake #1 Dam is a rock fill embankment with 25-foot-high steel facing. The dam is 217 feet long, with a 9-foot crest width. The upstream face consists of hand-placed rip-rap. There is no spillway. The outlet works consist of a 12-inch pipe with control valve and operator which discharges to a natural drainage, then to Albion Lake. The outlet works aze located ] 00 feet to the right of the left abutrnent. The inlet is a low-level conduit with control valves. There is no trash rack at the inlet. Green Lake #2 has a design capacity of 333 acre-feet. Its decreed volume is 333 acre-feet. Due to concems about the condition of the Green Lake #2 dam, the reservoir level was lowered on October 5, 1986. The reservoir is not cunently in active service pending repairs to the dam, and therefore, the current capacity is 0 acre-feet. At its decreed volume of 333 acre-feet, the reservoir surface azea is about 17 acres. Green Lake #2 Dam is a rock fill and earth fill dam with steel facing. It has a 40-foot ogee spillway. The dam was rebuilt by the Works Progress Administration (WPA) in 1941-1944. This effort resulted in a 220-foot dam. Green Lake #3 is created by a 290-foot-long, 30-foot high rock fill embankment with an upstream steel face. Its design capacity is 360 acre-feet, with a decreed volume of 285 acre-feet. Its tepoRed curcent operating capacity is 285 acre-feet. The dam was constructed in ] 906. In 1939, the WPA began the construction of a 35-40-foot high stee]- faced dam. In 1956 and 1960, repairs to the upstream dam face, including the installation of expansion joints and splash plates on the dam facing, were completed. The crest width of the dam is 5 feet. Steel splash plates, installed in 1956-1960, extend from the top of the steel facing about 2 feet above the embankment crest. The spillway is a rectangular, sharp-crested weir with a 12-foot crest length at the right abutment. The spillway depth is 13 feet. The spillway dischazges to a steep channel downstream of the dam. The weir is a metal plate embedded in the concrete floor and abutments of the spillway. The outlet works aze located in a vault excavated into bedrock approximately 50 feet downstream of the dam crest. The outlet consists of an 18-inch steel pipe which empties into a 4-foot diameter rock turmel. The control valve for the outlet is located in the vault. Dischazges aze made approximately 100 feet downstream of the dam. Green Lakes #4 and #5 aze natural impoundments with decreed volumes of 116.1 and 73.8 acre-feet, respectively. Their surface areas are 13 and 7 acres, respectively. Source Water Master Plan Chapter 3 Page 3-9 Preliminary Draft August 12, 2007 3.2.1.2 Albion Lake Albion Lake is formed by a 506-foot long concrete dam which is approximately 39 feet high at its ma~cimum sectioa The dam is curved and has a crest width of 14 feet. The dam was originally designed to have a masimum section height of approximately 60 feet. The contractor constructing the dam went bankrupt at the 39-foot height, and the dam was never completed. The dam is classified as a moderate hazard structure, primazily because of the lazge sudden inflow to Silver Lake that would result from Albion Dam failure. Albion Lake has a capacity of l,l ll acre-feet and drains an area of about 2 squaze miles. The Albion Lake azea was part of the 1907 watershed gra~t to the city. The original construction was completed by the city in 1911-1913. Concrete was mixed on site and delivered to the top of the dam in rail cazs as shown in Figure acac . A crest repair was made in 1938. In 1978, epoxy was applied to cracks in the upstream face of the dam, which eliminated much of the leakage occurring at that time. Flood releases are made through the rectangulaz, broad-crested weir spillway located 96 feet south of the left dam abutment. The spillway is 28 feet wide and the weir section of the spillway is 3.6 feet deep and 34 feet long. Spillway capaciry is 500 cfs. The spillway discharges to a steep cobble- and boulder-lined channel (SLA 1985~. Normal releases are made through two 24-inch diameter pipes comprising the outlet works. During 1987, the existing outlet works were demolished and replaced with a modern structure containing four 24-inch diameter gate valves. Two valves were mounted on each line for convol and guazd valve purposes respectively. The new structure replacement project was completed at a wst of $262,000. The new outlet works solved operational and safety problems associated with the old structure and valves. A 1988 study determined that the spillway is inadequate to pass the Probable Ma~cimum Flood (PMF) outflow of 3370 cfs but that the dam could safely be allowed to overtop. The PMF wouid overtop the dam by 1.5 feet for 7 hours. The existing dam is acceptably stable at its present height and for raises up to 10 feet (Hazza Engineering 1988). 3.2.1.3 Goose Lake Goose Lake is located in the southern valley of the Silver Lake Watershed. Goose Lake has a surface area of approximately 34 acres and a useable storage of 900 acre-feet. Its drainage area is approximately 4 square miles. Goose Lake Dam was originally constructed by a private individual from 1906 to 1908 as a 30-foot-high rockfill structure with a timber cribbing upstream face situated to raise the natural lake level of Oval Lake. It is now a 385-foot long, rock fill dam with a timber crib core, a concrete upstream facing, and a roller compacted concrete downstream face. The crest width is 20 feet. At its ma~cimum section, the dam is approximately 35 feet high. Goose Lake Dam is classified as a moderate hazazd dam. The dam's timber crib core served as the original dam before the dam was enlarged through the addition of the upstream concrete facing and placement of rock fill on the downstream face. The dam was reportedly damaged by a 1910 forest fire. In 1925, the city poured a concrete facing on the lower 13 feet of the upstream dam face. The WPA made repairs to Goose Lake Dam in 1935. In 1952, a 5-inch layer of reinforced gunite was applied to the upper part of the upstream face of the dam. Source Water Master Plan Chapter 3 Page 3-10 Preliminary• Draft August 12. 2007 In 1983, a portion of the dam was to be repaired by shotcreting. In preparation for the work, the contractor removed and burned several piles of rotten timber sheathing. Wind spread the fire to the exposed timber cribbing of the dam, and the dam was damaged for its entire length along the upper portion. In 1984, the damage was repaired with welded wire fabric tied to the 1952 gunite and to the welded wire fabric reinforcement of a new splash wall. Deadman anchors were placed in the rock fill to help tie the welded wire fabric to the dam and stabilize the 6-inch shotcrete ]ayer that was placed on a 10- by 385-foot section of the dam. In 1989, repairs were made to the outlet works, a new outlet house was constructed, and repairs were made to the spillway. Also in 1989, in an attempt to address large amounts of seepage through the dam, the downstream face was covered with roller-compacted concrete. Seepage continued, however, and the upstream gunite face began crumbling and failing. In 1998, a geo-membrane was attached to the upstream face and anchored in place by a new earthen upstream dam face. Seepage was reduced considerably Spillway channels are located at each abutment. The left abutment and right abutment spillway crest elevations are approximately 2.9 and 5.1 feet, respectively, below the top of the splash wal) located on the crest of the dam. The left (auxiliary) spillway is controlled by a concrete overflow wall while the right (main) spillway is 25-foot wide channel cut through natural rock. The peak PMF discharge at Goose Lake Dam is estimated to be 6750 cfs, while the spillway capacity is 750 cfs. Goose Lake Dam can be overtopped to safely pass the design flood (Harza Engineering-, 1988). 3.2.1.4 Island Lake Island Lake is located in the southern valley of the Silver Lake Watershed immediately above Silver Lake. lsland Lake Dam is a 747-foot-long concrete buttress (upstream face) and rockfill (downstream face) structure that was constructed in three sections separated by rock outcrops. The original dam was a rockfill timber crib structure built by J. P. Maxwell for the Silver Lake Ditch Company in 1890. The city bought the reservoir in 1906. The WPA reconstructed the dam with concrete in 1935. The city rehabilitated the dam in 1949. Island Lake is decreed for 372 acre-feet and has a current operating capacity of 333 acre-feet. It is classified as a low-hazard dam. It has a surface area of 33 acres and is about 14 feet deep. The main section of the dam is 619 feet long and contains the main spillway and outlet works. The middle section of the dam is the auxiliary spillway and is 107 feet long, with a crest elevation 1 foot lower than the main dam. The south section is 21 feet long. The concrete buttress is 1.5-2 feet thick, and the rock fill has a crest width of about 10 feet. Spalled concrete was repaired in 1979 and 1980, and the crest width was increased from 1.5-2 feet on the downstream face of the dam. A skim coat of mortar was also applied over the dam crest. The main spillway is located l 70 feet to the left of the right abutment of the main dam and consists of a 28-foot wide, boulder-covered chute in the concrete buttress with wing walls on either side. The auxiliary spillway is the middle portion of the dam. There are two separate outlets in the main dam located on either side of the main spillway. The north outlet is a 24-inch steel pipe, and the south outlet is a 12-inch steel pipe. Both are located in valve vaults that are part of the concrete buttress. The inlets are located on the upstream face of the dam and consist of concrete boxes covered by trash racks. Source Water Master Plan Chapter 3 Page 3-11 Preliminarv Draft Au~ust l2, 2007 3.2. l.5 Silver Lake Silver Lake is located in the southern valley of the Silver Lake Watershed and is the lowest lake in the watershed. Silver Lake receives water from both the north and south watershed valleys and discharges to North Boulder Creek. The decreed capacity is 4150 acre-feet and the current operating capacity of Silver Lake is .i996 acre-feet. Silver Lake's surface area is approximately 106 acres. Silver Lake is formed by a 1450-foot long earth fill embankment which is approximately 70 feet high at its maximum section. The dam was originally constructed by J. P. Maxwell for the Silver Lake Ditch Company in 1887 as a timber crib, rock fill dam. The city acquired the reservoir in 1906 and did some repair work at that time. The outlet through the dam was lowered with construction of a siphon structure in 1928. The new pipe, shown in the photo below, extending through the dam allowed the ciry to gain access to more water in the reservoir. In ]941, the original rockfill timber crib structure was replaced by an earthen embankment. The dam was enlarged in 19~6 and 1966. The design crest width is ?0 feet. The impervious core of the dam is composed of a dense, blue clay, glacial tilL The pervious shell is silty, sandy glacial moraine. Silver Lake Dam is classified as a high-hazard dam. Source Water Master Plan Chapter 3 Page 3-12 Preliminary Draft August 12, 2007 The spillway is a vertical-faced ogee weir with a side discharge channel cut into the right abutment of the dam. It is about 8.5 feet below the dam crest. The crest of the weir is 80 feet long, and the concrete weir wall is anchored in bedrock. The discharge channel is reinforced concrete for 130 feet, then bedrock- and riprap-lined for 290 feet. The 1988 PMF study identified the maximum discharge at Silver Lake Dam to be 10,800 cfs, while spillway capacity is 6350 cfs. Releases are made through the outlet works which pass through the dam. The outlet works consist of a trash rack-protected intake; a 470-foot-long, 48-inch inside diameter reinforced concrete conduit leading to the control valves located in a shaft beneath the crest of the dam; and a discharge pipeline which conveys releases to an outlet structure located at an earth-cut, rip rapped channel downstream of the dam. A 36-inch steel pipe has been placed inside the concrete conduit. The conduit bifurcates in the valve house, and each branch has two 24-inch control valves in tandem. There is also a 12-inch bypass pipe with two valves in tandem. The outlet works were installed in 1956 and raised and extended in 1966. In 1977, a number of piezometers and settlement monuments were installed after a slough developed to the left of the left wall of the spiliway along the downstream toe of the dam. A perforated pipe toe drain was installed in 1978. Inspection in 2002 revealed that the va)ve chamber was flooded with about five feet of water to just below the bottom ofthe grating above the valves. A second small diameter (approximately l-inch) piping system was discovered that is probably being used as a venture draining system to keep the water level in the valve chamber from rising to the phreatic water surface in the dam. It was also determined that the steel transition pipes upstream of the 24-inch guard valve and downstream of the 24-inch control valves were significantly corroded, and might need replacements. Valve replacement was recommended by the consulting engineer. 3.2.1.6 Silver Lake Diversion Structure The North Boulder Creek diversion into Silver Lake Pipeline was reconstructed in 1995 to incorporate instream flow measurement and discharge facilities into the structure for compliance with the North Boulder Creek instream flow program. As a part of the construction, the old regulating structure and Parshall flume were removed and disposed of. The need for diversion structure reconstruction was accelerated by extensive flood damage to the previously existing structure that occurred during the high runoff in the spring of 1995. The new structure was built to withstand the 100-year flood. The new structure is reinforced concrete with a reinforced concrete Parshall flume. A PVC stilling well and plastic coated steel conduit contain the flow monitoring equipment. The new diversion structure is configured differently than the previous one but has essentially the same footprint. There was no enlargement of capacity. The new instream flow measuring components provide accurate scientific measurement of low flows up to 10 cfs and discharge into the stream . The pressure transducer freezes at times during the winter. Source Water Master Plan Chapter 3 Page 3-13 Preliminarv Draft August 12, 2007 3.2.1. 7 Silver Lake Pipeli~re Silver Lake Pipeline was originally constructed of clay pipe in 1919. Some of the upper portions of the pipeline were replaced in the 194~s with pipe dating to 1906 salvaged from the Lakewood Pipeline replacement. In 1997-1998, the city removed the existing line and replaced Silver Lake Pipeline with a fully-gravity-pressurized, welded steel, concrete mortar-lined and tape-wrapped pipeline. The pipeline is 27 inches in diameter, has a nominal capacity of 20 MGD, and extends approximately 3.6 miles from the Silver Lake Diversion on North Boulder Creek located about 2 miles below Silver Lake to the Silver Lake Hydroelectric facility and Lakewood Reservoir. The pipeline carries both water released from Silver Lake and direct flow diversions from North Botilder Creek. The pipeline is buried to a depth of 4 feet to prevent freezing. The pipeline crosses city-owned land and lands under private and Boulder County ownership, over which the city holds a conservation easement. During completion ofthe Silver Lake Hydroelectric facility, the Silver Lake Pipeline experienced a hydraulic transient (water hammer) event of sufficient magnitude to damage air valves along the line. The pipeline itself was undamaged. Information concerning the Silver Lake Hydroelectric Project is contained in Table at the end of this section. Silver Lake Hydro is Federal Energy Regulatory Commission (FERC) Project P-l 1531 and received a conduit exemption from (icensing on December 24, 1998. The Silver Lake Hydro building was designed to blend with the local rural ranch architectural styles. 3.2.1.9 Nnrt/r Boulder Creek Diversiorr to Lukewood Re~servoir The North Boulder Creek diversion into Lakewood Reservoir was reconstructed in 1995 to incorporate instream flow measurement and discharge facilities into the structure for compliance with the North Boulder Creek instream flow program. As a part of the construction, the old regulating structure and Parshall flume were removed and disposed of. The need for diversion structure reconstruction was accelerated by flood damage to the previously existing structure that occurred during the high nmoff in the spring of 1995. Source Water Master Plan Chapter 3 Page 3-14 3.2.1.8 Silver Lake Hydro Preliminarv Draft August 12, 2007 The new structure was built to withstand the 100-year flood. The new structure is reinforced concrete with a reinforced concrete Parshall flume. A PVC stilling well and plastic coated steel conduit house the flow monitoring equipment. The new diversion structure is configured ditferently than the previous one but has essentially the same footprint. There was no eniargement of capacity. During construction, it was discovered that the pipeline leading to Lakewood Reservoir had been damaged. The pipeline was replaced with equivalent sized reinforced concrete pipe. The new instream flow measuring components provide accurate scientific measurement of low flows up to 10 cfs and discharge into the stream. 3.2.1.10 Como Creek Diversion The original Como Creek diversion structure, located on the southwest side of Lakewood Reservoir approximately 3 miles north of Nederland on Colorado Highway 72, was built in 1906. Como Creek was re-routed around Lakewood Reservoir at that time to prevent discharge of water contaminated with mine tailings into the reservoir. The diversion structure allowed selective diversion of Como Creek water at times that it was clear. In addition to allowing diversion of Como Creek water when desired, the structure canied water from the North Boulder Creek diversion structure into Lakewood Reservoir through a pipe culvert. By 1995, the diversion gates in the structure were no longer functioning and the entire structure was in danger of collapse. The structure consisted of two manually operated slide gates, a concrete weir across the creek, corrugated steel pipes and various other appurtenances. There was also a support structure that consisted of a concrete stilling basin, a metal Parshall flume, and an aerial crossing conduit on the west side of Como Creek immediately adjacent to the diversion structure. Como Creek Diversion maintenance was included in the Lakewood Pipeline construction contract and was completed in 2002-2003. As part of this contract, the original structures along with all of their appurtenances were removed and disposed of off site. The new Como Creek diversion structure is functionally similar to the original structure and has three distinct functions: 1. To provide a method to divert and measure the flow from Como Geek before it is discharged into Lakewood Reservoir; 2. To isolate Como Creek from Lakewood Reservoir at times of poor water quality in the creek, and; 2. To measure flow diverted from North Boulder Creek before it discharges into the reservoir. Riprap was placed on the banks upstream and downstream of the diversion structure to prevent ~mdercutting due to erosion and to protect the Lakewood Reservoir embankment. 3.2.I.II Lakewood Reservoir Lakewood Reservoir is an off-channel regulating reservoir associated with Boulder's Silver Lake Watershed and North Boulder Creek raw water supplies. It functions to regulate flows between two city raw water pipelines which operate in series and as a capture point for the city's North Boulder Creek diversions at Lakewood. The Silver Lake Pipeline carries direct flow from a higher point on North [ioulder Creek and storage water from the reservoirs located in Boulder's Silver Lake Watershed from the Source Water Master Plan Chapter 3 Page 3-15 Preliminarv Draft August 12, 2007 pipeline intake on North Boulder Creek to Lakewood Reservoir. At Lakewood Reservoir, water enters the Lakewood Pipeline for transport to the Betasso Water Treatment Facility. Lakewood Reservoir was constructed by Boulder in ( 906 as [he inlet regulating reservoir for the city's first pipeline in the North Boulder Creek Basin, Boulder City Pipeline, now known as Lakewood Pipeline, which was also built in 1906. Lakewood Reservoir also served as a settling basin built across Como Creek on the Boulder County Ranch (now Caribou Ranch). Due to contamination, principally from tungsten processing at the Primos Mill, Como Creek was diverted around Lakewood Reservoir soon after the completion of the Lakewood Pipeline in I906. The original dam was constructed of native soil and rock pushed into place. The dam was raised about 4 feet subsequent to the original construction. At completion of the reconstruction, Lakewood Dam had a maximum vertical height of 19.3 feet and a dam crest length of approximately 400 feet. Reservoir capacity is 42 acre-feet at reservoir surface elevation of 8181.0 feet (spillway crest elevation). The dam is classitied as a low hazard structure. 3.2.112 Lakewood Pipeline Lakewood Pipeline carries water approximately 1 l miles from Lakewood Reservoir to the Lakewood Hydroelectric facility and Betasso Water Treatment Facility. Lakewood Pipeline was originally constructed in 1906, and substantia(ly replaced in the 1940s and 19~Os. Lakewood Pipeline crosses U.S. Forest Service and private lands and Boulder County road ri~ht-of-way. The city initially proposed pipeline replacement in 1986, but the project became mired in a U.S. Forest Service environmental impact statement and decision process. After the U.S. Forest Service process was Source Water Master Plan Chapter 3 Page 3-16 Preliminary Draft August l2, 2007 completed, the city completed an Areas and Activities of State Interest (1041) review with Boulder County, which resulted in relocation of a significant portion of the proposed pipeline alignment to coincide with the Sugar Loaf Road corridor. The city reconstructed Lakewood Pipeline in three phases. Phase I reconstruction was exempted from the Boulder County 1041 permitting requirements and does not affect federal land. Construction began in the fall of 1994 and was completed in the summer of 1995. This phase of construction was located between the intersection of Kelly Road West and Sugar Loaf Road and the Betasso Water Treatment Facility. Phase I encompassed about 1.1 miles. The second phase of reconstruction began in July 2000. Phase II reconstruction included the westernmost 8,500 feet of pipeline from Lakewood Reservoir to approximately the point where the pipeline leaves the Cold Spring Road corridor and begins ascending Peewink Mountain. The Phase II alignment was common to all alternatives under consideration by Boulder County in the 1041 process and did not cross federal land, so it was allowed to proceed in advance. Pipeline installation was completed in November 2000 with final revegetation activities completed in the spring of 2001. The city executed the contract for Phase [II pipeline reconstruction in November 2001. Phase lIl construction was completed in July 2004. Phase iII extends approximately 8 miles from the south side of Peewink Mountain, up and over Peewink Mountain to Sugar Loaf Road. From its intersection with Sugar Loaf Road to the junction with Phase I at Kelly Road West, the pipeline is located beneath the surface of or immediately adjacent to Sugar Loaf Road. Lakewood Pipeline is a welded steel, concrete mortar-lined and tape-wrapped pipeline varying in diameter from 27 to 36 inches. Pipe wall thickness varies from 025 inches to 0.5+ inches. The pipe is buried beneath a minimum of 4 feet of cover to prevent freezing. The Lakewood Pipeline design flow is 20 MGD, with a nominal minimum flow of 8 MGD and "emergency" flow of 30 MGD. It has a maximum flow velocity at 20 MGD of 8 feet per second (emergency flow velocity at 30 MGD is 12 feet per second.) Pressures in the lower portion of the pipeline reach 850 psi. In addition to the pipe, there are drain vaults containing sleeve type valves to allow drainage of water from low points along the pipeline. The pipeline has redundant (2 valves per vault) air/vacuum and air release valves situated along the line. Passive corrosion protection is provided by sacrificial anodes with test stations at regular intervals along the alignment. Three fire hydrant assemblies (discharge to a holding tank with provisions for automatic tank refill) were installed along the upper (lower pressure) section of the pipeline~. A second surge relief valve was added to the Lakewood Pipeline in 2006 to provide additional protection over and above the original design against failure of this critical city infrastructure. Phase III pipe installed during 2002 is known to have numerous spiral manufacturing weld defects of a variety of types. Pipe installed during 2003 and 2004 was manufactured under careful inspection and is believed to free of manufacturing weld flaws. However, interior mortar defects appear to occur throughout the Phase III pipe. In accordance with the recommendations of a team of experts retained by the city, internal inspections of the Lakewood Pipeline were first completed in September 2004 and again in April and October 2005. A fourth internal inspection occurred in the spring of 2006. The next 2 Installation of the fire hydrants, which was required by Boulder County as a condition of 1041 permit issuance, required voter approval of a charter amendment to allo~v the city to provide ~vater above Boulder s"blue line." Source Water Master Plan Chapter 3 Page 3-17 Preliminarv Draft AuQust IZ. 2007 inspection will occur during the fall of 2007. The city will continue to monitor mortar condition and spiral weld corrosion. On May 12, 2004, the USFS issued Notice of Noncompliance for the Lakewood Pipeline easement. The letter states that "....the pipeline, as constructed, does not comply with the requirements of the Easement and related documents because it does not meet the original contract specifications and construction plans as accepted by the Forest Service......" In order to resolve the unauthorized use of National Forest System Land......the Easement must be amended to include the attached Liability clause with no additional revisions." On November 22, 1904 Forest Supervisor Jamcs Bedwell, in a letter to City Manager Frank Bruno, stated that the liability language in the new Lakewood Pipeline easement is inconsistent with other easements issued for similar projects and that the Forest 5ervice concerns regarding the city's acceptance of pipe that does not meet manufacturing specification has not caused the agency to impose any additional standards within the easement language. USFS issues with the existing easement for Lakewood Pipeline have yet to be resolved. 3.21.13 Lukewood Hydro Information on the Lakewood Hydroelectric Project is contained in Table xx at the end of this section. Lakewood Hydro is FERC Project P-09922 and was issued a conduit exemption from licensing on February 9, 1987. The Lakewood Hydro equipment is co-located with Betasso Hydro at the Betasso Water Treatment Facility. 3.2.2 Middle Boulder Creek/Barker Reservoir Water Facilities Middle Boulder Creek water facilities include the Boulder Canyon Hydroelectric Project and Skyscraper Reservoir. The Boulder Canyon Hydroelectric Project (often referred to as the Barker system) was completed in 1910 by a predecessor to Public Service Company of Colorado (PSCo). Beginning in the 1950s, the city had a series of agreements with PSCo regarding use of Barker Reservoir storage and its associated water transmission facilities. The city has used an exchange right since 1954 which allows the ciry to divert water out of priority at upstream diversion points in the Boulder Creek basin and replace it at downstream locations below the Boulder Reservoir and Baseline Reservoir outlets. In many years, most of the water the city stores in Barker Reservoir is replaced with Colorado Big-Thompson water released from Boulder Reservoir. The city purchased the Boulder Canyon Hydroelectric Project from PSCo in 2001. The city completed the Middle Boulder Creek Water Source Management Work Plan in 2002. This study compiled and evaluated existing infvrmation for the Middle Boulder Creek watershed, included extensive public involvement in the city's planning efforts, and recommended tnanagement decisions and work effort for the immediate future. Facilities associated with the Middle Boulder Creek water source and the Boulder Canyon Hydroelectric Project are shown on Figure _ and listed in series from west to east, below: 3.2.2.1 Skyscraper Reservoir Boulder owns Skyscraper Reservoir, located on Wc~odland Creck within the Indian Peaks Wilderness area. Skyscraper's currcnt storage capacity is 146 acre-feet. The dam is a 122-foot-long, 24-foot-high rock masonry gravity arch. The crest width at the top of the dam is 3 feet. It was constructcd between 1940 and 1950 by Everett Long to irrigate Long's Gardens by raising the level of an existing lake. Long's Gardens intended to use the water for irrigation of dahlias for commercial sale. However, it was Source Water Master Plan Chapter 3 Page 3-18 Preliminarv Draft August 12, 2007 determined that dahlias were too water intensive and the Long's Gardens operation was refocused on growing irises. The city purchased Skyscraper Reservoir in 1967. Skyscraper Reservoir has an 11.5 acre surface area and drains an area of about 0.4 square mile. It is classified as a low-hazard dam. The dam includes a 38-foot-wide spillway section located near the center of the dam which is 3.2 feet lower than the top of the dam. It has an 18-foot-long discharge channel and a capacity of 651 cfs. There are two outlets. One consists of an 8-inch inside diameter, 10-foot long conduit with a wooden plug located 14 feet below the dam crest. The capacity of this outlet is 6 cfs. A second, low level conduit with a control valve is located 18 feet below the embankment crest. It is 13 feet long and 12 inches in inside diameter, with a capacity of 15.9 cfs. While the reservoir is nominally functional, the city does not actively operate it because of its remote location and small size. Instead, Boulder has informally relied on Skyscraper as a`reservoir of last resort' for extreme droughts. The 2003 City of Boulder Drought Plan recommended that the city formally incorporate the operation of Skyscraper Reservoir into its water supply system on a normal basis. 3.2.2.2 Burker Reservoir Barker Reservoir has a surface area of approximately 200 acres and can hold approximately 11,700 feet of water. While the shoreline of Barker Reservoir is open to public access and recreation, no camping, boating or swimming are currently allowed. Barker Dam was built in 1909- 1910 and is located 11.5 miles west of the Betasso Water Treatment Facility. The dam is 175 feet high with a crest of 720 feet and is made of cyclopean concrete. It has two 36-inch diameter floodgates that discharge down the spillway and into Middle Boulder Creek. The outlet works include 10 outlet gates on the upstream face of the dam that discharge into a vertical, stair-step shaft in the dam that can release flows to Middle Boulder Creek and the Barker Source Water Master Plan Chapter 3 Page 3-19 Preliminarv Draft Au~ust l2, 2007 In 1946-1947, PSCo modified the outlet works on Barker Dam and made improvements to the upstream face of the dam. In 1971, the spillway was enlarged with a new 12~-foot ogee crest with a curved channel and a warped floor. The new spillway was designed to pass flood flows from a 6-hour storm generating 2.45 inches of precipitation and peak flood outflows of 4.544 cfs. Cosmetic improvements were made to the downstream face of the dam in 1971. The dam was secured in the early 1980s with post-tensioned anchors to increase the factor of safety. The city paid for the repair at a cost of $3,3 I ~,000 and received a perpetual right to use 8000 acre-feet of Barker Reservoir storage space from PSCo in return. The downstream face of the dam is cosmetically flawed but the structure of the dam is sound. Leakage and ice build-up on the downstream face of Barker Dam were noted during the 2003-2004 winter season. The city has attempted to clear the vertical drains of debris and extended the drain outlet below the dam by approximately 250 feet. The city has concluded that the condition of the vertical drains has no negative impact on dam stability, and the drains continue to function, although at a reduced rate. The ninth safety inspection of Barker Dam was completed in 2006. This included a Probable Failure Modes Analysis (PFMA). The PFMA concluded that there are no credible Flood related Potential Failure Modes for any of the Boulder Canyon Hydroelectric faci(ities. the seismic stability of Barker Dam should be verified for peak ground accelerations, and all the Boulder Canyon Hydroelectric facilities are well constructed and well operated. In response to public comment, the city completed a non-motorized boating feasibility study for Barker Reservoir in 2003. The study identified concerns regarding safety, water quality, and faciliry security. Allowing non-motorized boating on Barker Reservoir would greatly accelerate the need to upgrade Betasso Water Treatment Facility to advanced water treatment processes compared to maintaining the current no boating policy. In addition, revenue generation capability from a boating program was found to be poor. While the Boulder City Council declined in 2003 to subsidize a boating program, the Town of Nederland was invited to submit a proposal to manage a boating program. To date, Nederland has not submitted any proposals. 3.2.2.2 Barker Gravity Li~re The intake for the Barker Gravity Line is the Farmers' Gate located at the base of Barker Dam. The gravity line is a buried (close to grade), 36-inch diameter, concrete pipeline that extends approximately 1 I.7 miles to Kossler Reservoir. Its current capacity is approximately 43 cfs. The pipeline includes 5 tunnels and 7 inverted siphons. Water flows by gravity in open channel mode in most sections of the pipeline. Pressurized flow develops in the siphons where water pressures range up to 86 psi. In 2006, the Farmers' Gate wooden timbers were replaced providing a short term fix for structure deterioration. A full gate replacement with a stainless steel gate is planned for 2007. 'I'he Barker Gravity Line was in a seriously deteriorated condition when the city purchased the Boulder Canyon Hydroelectric Project in 2001. Leaks accounted for approximately 10 percent total water loss. The city has since developed and implemented an annual maintenance program to address the most critical problems. Repairs are generally limited to times of the year when the Barker Gravity Line is not needed to deliver water to meet municipal demand. Primitive access and rugged terrain require use of a helicopter to deliver pipe and other supplies in some areas. The major repairs completed from ?001-2006 are: • Drain valves and valve vaults for Siphons l, ?, 3, ~, 6, and 7 were replaced with new 8-inch ball valves and new valve cans. Source Water Master Plan Chapter 3 Page 3-20 Preliminary Draft August 12, 2007 • 121 manhole frames and lids were replaced with new steel frames and lids. • HDPE pipe was removed from both sides of Siphon 5 and from the east side of Siphon 6. • Concrete pipe was removed from the lowest 40- to 50-foot sections of both sides of Siphon 5 and was replaced with mortar-lined steel pipe. • Three heavily damaged sections of pipeline were removed and replaced with mortar-lined steel pipe. • Damaged, hand-stacked rock retaining walls supporting the pipe bench were replaced with reinforced concrete counterfort style retaining walls in three locations along the pipeline. • Numerous ]eaking joints in the existing concrete pipe have been repaired with grout and/or internal pipe seals. • The entire pipeline has been cleaned of debris and root mass has been removed. In February 2006, an overflow event was discovered in the Barker Gravity Pipeline that caused large amounts of muddy water and silt to spill into Boulder Creek. Due to an ice blockage that formed in Siphon 4 during a maintenance shutdown, water backed up and spilled out of a manhole during pipeline refilling operations. Significant erosion damage occurred between the gravity line and the creek below. Cleanup and restoration took place in 2006 and 2007. The section of pipe just upstream of Siphon 4 will be replaced in 2007. Other than a shutdown to accommodate ice removal in Siphon 4, no other disruption in flow capability occurred as a result of the overflow damage. The ninth safety inspection of Barker Dam was completed in 2006. This included a Probable Failure Modes Analysis (PFMA). Of all the components of the Boulder Canyon Hydro Project, Barker Gravity Pipeline has the highest potential for failure. 3.2.2.3 Kossler Reservoir Kossler Reservoir is the forebay for the Boulder Canyon Hydroelectric Plant and is located 2 miles south of the plant. The Barker Gravity Pipeline ends at the southwest side of Kossler where there is a weir and a measuring device. The penstock gatehouse is located on the north side of the reservoir where there is another measuring device. Kossler is a 1 b5 acre-foot, crater type reservoir formed by one main dam and two smaller dams. The main dam is a 45-foot-long, 20-foot high embankment with an 8-foot-wide crest. The upstream face of the main dam is covered with concrete. The two small dams are irregularly shaped, low embankments that fill in low areas along the reservoir rim. There is no spillway on Kossler Dam as the reservoir has a limited natural drainage area, is filled by controlled releases, and is used as a regulating reservoir. In 2006, the Kossler inlet structure was repaired. Old lumber and concrete were removed and sand and silt were excavated from the inlet. Treated lumber was installed for a hydraulic dissipater and a new in(et structure and concrete for a retaining wall under the stilling shack was installed. Rip-rap was placed around the spillway and inlet. Following the September 2006 inspection of the Boulder Canyon Hydro Project, FERC requested that the city prepare a plan for addressing the deterioration of the concrete on the upstream face of the main dam and rodent disturbance of the dams. The city plans to complete the concrete repairs during 2007 and will continue to monitor rodent activity. The ninth safety inspection of Barker Dam was completed in 2006. This included a Probable Failure Modes Analysis (PFMA). Very little design and construction documentation is available for the Kossler Reservoir dams and appurtenant facilities. The PFMA identified two potential actions with respect to Source Water Master Plan Chapter 3 Page 3-21 Preliminan Draft Auoust 12.2007 performance monitoring: the hazard classification of the Kossler Reservoir dams should be reviewed and the size and capacity of thc over(low spillway on the west dam at Kossler Reservoir should be detennined. 3.2.2.4 Boulder Cn-:yo~r Hydro Peiistock The steel penstock to the E3oulder Canyon Hydro plant serves as the outlet from Kossfer Reservoir. The penstock drops approximately 1,835 feet from Kossler Reservoir to the Boulder Canyon Hydro Plant. The pipeline is 48 to 54 inches in diameter and consists of welded and riveted steel pipe. Penstock operating pressure is approximately 800 psi at Boulder Canyon Hydro. When constructed in 1909, Boulder Canyon was the highest head hydroelectric project in the U.S. High water pressure caused the riveted steel pipeline to leak profusely. The "ball peen" welding process was developed on-site to eliminate the leaks in the penstock. For this (and other) reasons, the Boulder Canyon Hydroelectric Project is considered to be a significant historic site and has been determined eligible for nomination to the National Register of Historic Places. The Boulder Canyon Penstock was externally inspected in 2005 (TCB 2005). (nternal inspection was completed in 200~-2006. An access manway was installed just above the steep portion of the penstock alignment in 2005. In 2006, a second access manway was installed just upstream from the hydroelectric plant bui(ding. A small leak was repaired upstream of the hydro plant building during 2006. 3.2.2.5 Boulder Canyun Hydrv Information on Boulder Canyon Hydro is contained in Table xx at the end of this section. Boulder Canyon Hydro was purchased from PSCo on March 7, 2001. The Boulder Canyon power plant went into operation on August 4, 1910. Thc original capacity of the single turbine generator was 10.000 kilowatts. A second turbine generator was added in 1936, and the Source Water Master Plan Chapter 3 Page 3-22 Preliminary Draft August 12, 2007 capacity was increased to 20,000 kilowatts. In late 2000, prior to the closing on the city's purchase of the facilities, the windings on one of the generator units grounded out. This event caused extensive damage to the generator and left it inoperable. Therefore, current actual capacity at Boulder Canyon Hydro is 10 MW. When it was purchased by the city, hydroelectricity became a by-product of project operation as a component of the municipal water supply system, and the 10 MW capacity is no longer supported. Boulder Canyon Hydro is FERC Project P-1005. The license for the project that was issued to PSCo on Apri128, 1981 was transferred to the city at the time of purchase. The license expires in August 2009. The city is seeking a conduit exemption from licensing for the project rather than renewing the license. 3.2.2. b Betasso Penstock Betasso Penstock transmits Middle Boulder Creek Basin and Barker Reservoir water from just above the Boulder Canyon Hydro plant to Betasso Water Treatment Facility. Water arrives at a pressure of approximately psi. Built in the 1960s, it originally consisted of an unlined, 20-inch-diameter, 20-inch welded steel pipeline with exterior coal tar enamel coating. With the construction of Betasso Hydro in the mid-1980s, the pipe was lined with concrete mortar to protect it from corrosion. An external condition assessment of this pipeline conducted in 2005 (TCB 2005) concluded that the exterior is in good condition. An internal video inspection during the fall of 2006 verified that the lining is in good condition, although it has a rippled or ridged surface which causes a loss of energy in the water flow due to friction. The city intends to construct a new, 33-inch diameter, welded steel and concrete mortar lined pipeline to replace the existing Betasso Penstock during 2007-2008. The existing penstock will be reused in place to replace the upland (non-floodplain) portion of the Orodell Treated Water Pipeline. The new pipeline will increase water system reliability and allow Betasso Hydro to achieve its intended generation capacity of 3.2 MW, thereby increasing hydroelectric power revenue to the city. Reuse ofthe existing pipeline will significantly delay replacement ofthe Orodell Pipeline. The upper portion of Orodell Pipeline will be reused in place to create a means to discharge raw water from the Betasso and Lakewood Hydroelectric Facilities to Boulder Creek. This will heip to alleviate pressure placed on the Betasso Water Treatment Facility resulting from rapid increases and decreases to plant inflows during contractually-required, monthly hydroelectric generation capacity tests. The Howell-Bunger pressure reducing valve on the Betasso Penstock was installed prior to construction of the Betasso Hydroelectric Facility and continues to be used during periods when Betasso Hydro is out of service. The current valve is not the proper valve for the installation and the operating mechanism is out of date. Extensive repairs have been required in the past and replacement parts must be custom fabricated. Design and installation of a new pressure reducing valve will be completed in conjunction with the replacement of Betasso Penstock . Source Water Master Plan Chapter 3 Page 3-23 Preliminary Draft August 12, 2007 3.2.2. 7 Betasso Hydro Information on Betasso Hydro is presented in Table I at the end of this section. Betasso Hydro is FERC Project P-06282 and was issued a conduit exemption from licensing on August 20, 1984. While the Betasso unit has a rated capacity of 3.2 MW, the plant currently can only achieve about 2.4 MW due to operating constraints in the Betasso Penstock. Replacement of the Betasso Penstock, scheduled for 2007-2008, will allow Betasso Hydro to achieve its intended Both the Lakewood Hydro and Betasso Hydro facilities are located in the same building adjacent to the Betasso Water Treatment Facility. 3.2.3 Betasso Water Treatment Facility The Betasso Water Treatment Facility, located west of the city near Sugarloaf Mountain, was originally constructed in 1964. lt was expanded to its present capacity in 1976. At about the time of the expansion, 50 MGD became widely accepted as the design capacity of the Betasso facility. However, hydraulic limitations and the need to limit flow into the filter beds to meet drinking water standards cause actual maximum facility capacity to be closer to 45 MGD. capacity and will increase hydropower revenue to the city. Source Water Master Plan Chapter 3 Page 3-24 Preliminary Draft August 12, 2007 The city's North and Middle Boulder Creek basin water supplies are treated at Betasso Water Treatment Facility. Water from the North Botilder Creek basin passes through the Lakewood Hydroelectric turbine or a pressure reducing valve, discharges to the tailrace and flows at atmospheric pressure into the treatment facility. Water from the Middle Boulder Creek basin passes through the Betasso Hydroelectric turbine or a Howell-Bunger pressure reducing valve to the tailrace and flows at atmospheric pressure into the treatment facility. 3.2.4 Boulder Reservoir Raw Water Facilities 3.2.4.1 Boulder Reservoir Boulder agreed to build Boulder Reservoir as part of the agreement to enter the Northem Colorado Water Conservancy District (NCWCD) and receive Colorado-Big Thompson Project (CBT) water. Conditions for annexing to the NCWCD included back-paying fifteen years of assessments, constructing Boulder Reservoir and providing the NCWCD with storage space in the reservoir (Annexation Agreement, 1953). The city floated $1.2 million ofutility revenue bonds to purchase land and fund construction ofthe dams for the reservoir. Boulder Reservoir, originally call Twin Lakes Reservoir, was completed in April 1955. The reservoir was originally built to store agricultural and industrial water for downstream CBT users and to exchange municipal water for the city. Having the potential to exchange water in Boulder Creek is of vital importance to the city since it allows the city to make nearly full use of the physical supply of water at its upper diversion points. This increases the city's ability to reliably meet its water supply demands. The dams and reservoir are owned by the city but maintained and operated by the NCWCD. The reservoir was constructed to a capacity of 13,100 acre-feet. When full, the reservoir has a surface area of approximately 700 acres. Use of the storage space is controlled by a contract between the city and NCWCD with the amount of storage useable by each entity varying by season. The reservoir is contained by two rolled earth-fill dams averaging 3,000 feet in length, 50 feet in height, and 150 feet in width at the crest. The embankment materials are sand and gravel placed with more permeable soils toward the outer slopes. A centerline cutoff trench that extends to unweathered clay shale bedrock controls foundation seepage. Downstream toe drains control seepage through the embankments. The spillway is an earth channel upstream and downstream of a concrete labyrinth weir crest section situated on the left abutment of the north dam. Prior to 1985, the State Engineer's concern about erosion of the earthen spillway crest caused the imposition of a reservoir storage restriction to create a flood storage pool. The city paid $939,00 to modify the spillway in 1985 to add height to the concrete crest and to harden the earthen spillway with a concrete face. By hardening the spillway against erosion during high flows, the State Engineer's storage restriction was lifted to allow storage of 13,100 acre feet as originally planned. The spillway modification increased the maximum discharge capacity (at a pool elevation of 5,188.50 feet) to 25,500 cfs. This discharge capacity is considered adequate to pass 61 percent of the probable maximum flood (PMF). Boulder Reservoir has two outlets. The main outlet, in the north dam, is operated by NCWCD and leads to the Boulder Creek Supply Canal. The maximum discharge capacity of the main outlet is 940 cfs. The auxiliary outlet, in the south dam, is owned and operated by the city and serves as the intake to the water treatment facility. The city's outlet is 10 feet lower than the main outlet and allows the city to access about ] 000 acre-feet of the city's long-term storage water in the event of an extended drought. The maximum discharge capacity ofthe auxiliary outlet is 475 cfs. It was last inspected in 19_. Source Water Master Plan Chapter 3 Page 3-25 Preliminarv Draft August l2. 2007 Boulder Reservoir offers full recreation amenities, with swimming, boating, picnicking, fishing, and special event permits. It has tlle largest guarded swimming facility in the state. Recreation at the reservoir is managed by the city through the Parks and Recreation Department. 3.2.4.2 CBT Project Facilities ut Buulder Reservoir 3.2.;1.2.1 Boulder Feeder Canal Completed in the late 1950s, the canal is operated by NCWCD. In Boulder County, the canal generally runs from north to south from Rabbit Mountain to Boulder Reservoir. The canal is located on land either owned in fee or easement by NCWCD, with a few areas under the jurisdiction of the Bureau of Reclamation, and some other exceptions at siphon locations (sites where the canal is underground in order to avoid conflicts with the larger drainages). The capacity of the Boulder Feeder Canal is 200 cfs. The diversion inlet at the Boulder Feeder Canal consists of removable stop planks across the canal bottom; a partially submerged, 5-foot wide, manually cleaned bar screen (2-inch openings) built into the side of the canal, and: a stainless steel, woven wire basket ( I /2-inch openings) that can be winched up to grade for cleaning. A manual sluice gate is installed for isolating the facility from the canal. About 5,600 feet of 42- inch diameter piping connects the diversion inlet to the Boulder Reservoir Water ~'reatment Facility at 63`J Street. I~he raw water line was designed for a tlow of 30 MGD, and provisions were made for a parallel 42-inch line at the diversion inlet in the future. The raw water line drops almost 70 feet to cross under the Boulder Supply Canal north of the treatment facility. The raw water line then rises 3~ feet to the treat-nent facility. Canal operation is dictated primarily by the amount of demand for CBT deliveries for municipal and irrigation uses. The canal is typically out of service between November and April each year due to freezing. The water from the canal is typically easier to treat than water from the reservoir due primarily to the high mineral content of the soils surrounding the reservoir, the runoff from intermittent North and South Dry Creeks, and evaporation. However, the runoff into the canal and lack of security along the open canal make the pathogen risk with using canal water very high. The Boulder Feeder Canal has historically been closed to public use. In 2006, an 1 1-mile recreational trail was proposed along the Boulder Feeder Canal from U.S. Highway 36 southeast of Lyons to Boulder Reservoir. This trail connection would link open space and trails near Boulder Reservoir with recreation areas in northern Boulder County. A trail along the canal has been on the Boulder County Trails Map since 1978. The ciry of Boulder Open Space and Mountain Parks Department and Boulder County Parks Source Water Master Plan Chapter 3 Page 3-26 Preliminary Draft August l2, 2007 and Open Space Department are now pursuing trail development in this corridor to complete a regional trail between Boulder and Lyons, eventually connecting to Hall Ranch and Longmont. 3.2.4.2.2 Boulder Supply Canal The Boulder Supply Canal is that portion of the Boulder Feeder Canal located downstream of Boulder Reservoir. The Boulder Supply Canal transfers water from Boulder Reservoir to Boulder Creek just upstream of the Wastewater Treatment facility. This water provides a major increase in the streamflow in this reach of Boulder Creek during the warmer months of the year. The Boulder Supply Canal is owned by the United States Bureau of Reclamation and operated by the Northern Colorado Water Conservancy District. The canal has a carrying capacity of 200 cfs, and it was constructed to supply CBT water to the South Platte Supply Canal, which transports CBT water from Boulder Creek to the 5outh Platte River. The city is guaranteed the use of up to 90 cfs of the capacity and may use additional capacity on an as- available basis. The city uses the canal to deliver the city's exchange water to downstream senior water rights and the city's agricultural lease water. 3.2.4.3 Furmers Ditch The headgate for the Farmers Ditch lies on the north side of Boulder Creek just upstream of Eben G. Fine Park. The ditch runs north through the west side of Boulder, starts heading northeast around Iris Ave, runs north through Boulder Valley Ranch, and terminates at the southern edge of Lake Valley Estates. Numerous laterals branch off the ditch including one at the end of the ditch that carries water to Boulder Reservoir. The city measures the amount of water delivered to Boulder Reservoir via Farmers Ditch in a two foot Parshall flume located on the northeastern most lateral of the ditch, which lies on Boulder Valley Ranch property near the old Open Space and Mountain Parks fire cache on 515` St. The city uses the Farmers Ditch to carry up to 24.602 shares of Farmers Ditch water to the reservoir for municipal use. The water is decreed for direct use only and so must be used immediately upon delivery into Boulder Reservoir. If the BRWTF is not drawing directly from Boulder Reservoir at the time, then the Farmers Ditch water is counted against the deliveries into the BRWTF directly from the Boulder Feeder Canal. In effect, the water is exchanged for CBT water which is then accounted for as having entered Boulder Reservoir and is available for later use by CBT allottees. If the BRWTF is not in operation at the time that the Farmers Ditch water is available, then the city cannot take the water since it must be used directly. The city may also carry water other than decreed Farmers Ditch water (a.k.a. foreign water) through the Farmers Ditch according to the terms and conditions in a carriage contract signed on May 2, 1967 by the city and the Farmers Ditch Company. The contract permits the city to utilize excess capacity in the ditch to carry city-controlled foreign water. In exchange for this usage right, the city pays the ditch company one-sixth of the company ditchrider's annual cost and an annual surcharge based on the number of days the ditch carried city-controlled foreign water. 3Z.5 Boulder Reservoir Water Treatment Facility at 63~d Street The Boulder Reservoir Water Treatment Facility at 63`~ Street was originally constructed in 1971 to provide additional water treatment capacity during summer peak flow periods by treating water from the city's CBT/Windy Gap source. Prior to construction of the facility, Boulder's CBT water was only used by exchange to Barker Reservoir and the Silver Lake Watershed. The facility is normally operated in the Source Water Master Plan Chapter 3 Page 3-27 Preliminan~ Draf[ August l2, 2007 range of 5 to 8.~ MGD but is commonly run at up to 11.5 MGD during peak demand periods and can be run down to 4 MGD. The current capacity is l6 MGD. From 1972 until 1996 the Boulder Reservoir facility operated mostly during the peak demand months and was shut down for the remainder of the year. Since 1996, the facility has operated year round; 24 hr/day during the peak demand summer months (May - Oct.) and 12 hr/day during the low demand winter months (Nov - Apr.). When factars such as the costs of the treatment chemicals and water pumping are considered, the cost of treated water from the Boulder Reservoir facility is approximate(y twice the cost of treated water from Betasso. Table . Treated Water Unit Production Costs (Per Million Gallons) 1996 1997 1998 1999 2000 2001 2002 2003 2004* 2005* 2006 Betasso $239 $274 $3l6 $317 $319 $334 $360 $365 $352 $456 $428 Boulder Reservoir $~76 $560 $583 $645 $487 $534 $716 $860 $1289 $876 $905 Source: City of I3oulder Utilities Division Annual Report, 200~ and 2006. *2004 and 200~ included capital improvement budgets. The Boulder Reservoir Water TreaUnent Facility was out of service for two months in 2U0~ and four months in 2004. The facility is staffed year round. Water is transported to the treatment facility from one of two intake structures: along the Boulder Feeder Canal or in the reservoir itself (Figure ~. Because Boulder Reservoir is at a lower elevation than the treatment facility, raw water must be pumped to the influent structure. The raw water pumping station was constructed in 1981 and is connected to the auxiliary outlet trash rack structure in Boulder Reservoir. The trash rack structure was modified in 2005 and is a concrete, octagonal, upturned bell-mouth design located a foot above the bottom of a rock-lined channel, about 20 feet below the normal pool elevation. ~ _ ~, ~ ,.~_~. .~. _ ;-~. ~ -. ., -~ ,,..u Each peripheral face of the raw water intake has a 2-foot by 4-foot trash rack (1 3/4- inch openings) over the inlet port. A 54-inch square trash rack cover is installed on the top of the structure. Provisions were made for water withdrawal at a lower depth if needed, but this can only be accomplished by sendine a Source Water Master Plan Chapter 3 Page 3-28 Preliminary Draft August l2, 2007 diver to manually remove the inlet apron. The raw water passes through a 48-inch diameter conduit through the dam. Three vertical diffusion vane raw water pumps, each installed in a 48-inch diameter suction can, pump water to the treatment facility. One pump is rated at 4 MGD; the other two are rated at 8 MGD each. The pumping station was designed for five 8 MGD pumps at build out. Four constant-speed, 2S0 horsepower, horizontal split-case centrifugal pumps convey finished water from the treatment facility to Pressure Zone 1. Each pump has a rated capacity of 2,800 gpm (4 MGD), and two additional high-service pumps were added at 2,800 gpm for a total capacity of 12 MGD. The discharges combine prior to the flow tube vault south of the Filter Building, which measures the finished water flow from the facility. A 30-inch diameter check valve with two 3-inch diameter bypass lines is also located in the flow tube vault and provides surge protection. House service water and fire- suppression system water is obtained via two connections immediately downstream from the flow tube vault. 3.3 Water Rights and Water Contracts The city owns water rights of several types that are used to provide municipal water supply. These inctude direct flow rights, storage rights, exchange rights, and contract water delivery rights. Some of these water rights were originally decreed to the city for municipal use. Other water rights were originally attributable to shares in local irrigation companies and were decreed for agricultural use. These rights were purchased by the city and changed through court proceedings to allow municipal use. Some of these water rights have gone through another court proceeding to allow instream flow use. Under the contract delivery rights, the actual water rights are held by another entity, such as the Bureau of Reclamation, but the city has a right to have water delivered according to the terms of the contract. The city also owns water rights that are decreed for agricultural use and are used for irrigation of open space and parks. The city's water rights and contract rights that are used for municipal water supply are held by the city as an asset within a restricted budgetary fund called the Water Utility Enterprise Fund. These assets are restricted under the City Charter for preferential use for Water Utility purposes and are listed separately from General Fund assets in the city's accounting system. Most of the city's water rights that are used for irrigation of open space or for parks are held within the General Fund, but Utilities Fund water that is not immediately needed for Water Utility purposes is sometimes leased to other city departments. Historically, the city has also leased to farmers, on an annual basis, any CBT water and some ditch share water that is not needed for municipal supply in any given year. The city owns an extensive municipal water rights portfolio that includes rights on North Boulder Creek, Middle Boulder Creek, and main Boulder Creek. The city's water rights in the Middle Boulder Creek basin are associated with Barker and Skyscraper Reservoirs and the Barker Pipeline. Water rights in the North Boulder Creek basin are associated with Albion Lake, Goose Lake, Island Lake, the Green Lakes, Silver Lake, Park Reservoir, the Silver Lake Pipeline, and the Lakewood Pipeline. Water rights located on main Boulder Creek are either used at these facilities by exchange or are carried to Boulder Reservoir through Farmers Ditch. In addition, the city has contract delivery rights from the Colorado-Big Thompson (CBT) Project and Windy Gap Project that supply water delivered to Boulder Reservoir. The city's municipal water rights portfolio is summarized in Tables _ through _. A detailed presentation of the city's municipal water rights is included in Appendix _. Source Water Master Plan Chapter 3 Page 3-29 Preliminarv Draft August 12, 2007 Table : City of Boulder Dam and Reservoir Summary Data ~ . ~ s ,~ . . 2 .' 'Iax. ~, _ _ ~ ~;ilwat~s _"- llecreed Op. Urainagc ( rest liouom Uisc6:u-~;~. :~rea Dcpth VoL (:-- Cap~~ :1rca Type Crest Crest Ileight Ha7ard T~~pe F.levation 1~'idth Length Crpy \Ame acres) feet ~ t) (a-~ miZ) Len th Li'idth (feet) Class. ft) ft) (f'ect) cfs) Kock1'ill w/steel Grecn #1 I I 14 175 92 0.2 facm 2l7 9 25 Low None Kocklill and eanhfill with Green #2 17 37 333 0 steel Cacin Ooee 0.12 feet Sharp below Rockfill wrth crested embankment Green #3 l9 29 285 28~ L t steel fac~n 290 5 30 Low ~a•eir crest l2 50 ~0 Grcen tta l 3 I S I 1 G Natural Natural Grcen #5 7 10 74 Natural Natural Broad 3.6 fect Concrete Gravity crested below dam :\Ibion 32 35.3 I l l] 203 Arch 506 14 38 9 Moderate weir crest '_'8 48 500 Rocklill/fimber cnb wlconcrete Guose 34 27.8 103G U/S lacc Main- 619 rocktill (main~ chute; 107 (aux Aux - Main - I S spw~ ~ I>-2.0 broad below crest; Concrete Buttress 21 (buuress): crested Aux - 0.9 Island 33 14 334 androckfill (south) f0(rocktill) Ib Low weir belowcrest Ogee Silvcr 105 G2 3987 8 8 BarthCdl 14~0 20 70 Hi h crest 10,262 SO 130 72~1 I Lake~cood NA Earlhen 400 19 3 Low 8181 Ogee Rock masonrv concre[e Skvscra ~er 14G ~ravitv arch l22 3 24 l.ow weir 3 below crest 38 l8 65l Cyclopcan Ogee Barker 200 conerete ~20 ]75 }li h crest 4~4d Isarthen (3); mam has cnncretc U/S ICossler NA face 45 20 Low None Concrete 3000 labvrinth Roulder 700 2 rollt~d earthfill (a~•e.) l~0 ave ) SU ave.) weir 25500 ude SI..A 1~8~ Harza 1988 GE[ Consultants et al 2002. _ l. Principle sources of data inc I _ _ 2. At crest of'main spillwa~~. Source Water Master Plan Chapter 3 Page 3-30 Preliminary Draft August 12, 2007 Table :City of Boulder Raw Water Pipeline, Penstock and Canal Summary Normal Op. Name Start End ConsMuction Length Diameter Flow Pressure Capacity Last Major as stated inches si MGD Re air Silver Lake Silver Silver Welded 3.6 miles 27 Gravity- 660 20 Replaced - Pipeline Lake Lake steeVCML pressurized 1997-1998 Diversion Hydro/ Lakewood Reservoir Lalcewood Lakewood Lakewood Welded llmiles 27-36 Graviry- 800 20(normal) Replaced- Pipeline Reservoir Hydro/ steeVCML pressurized 30(emergency) 1994-2004 Betasso WTF Barker Farmers Kossler Concrete 119 miles 36 Open channel Up to 86 psi 27.8 On-going Gravity Line Gate (at Reservoir gravity flow in siphons since 2001 the base w/pressurized of Barker inveRed Dam) siphons Boulder Kossler Boulder Welded and 1835 feet 48-55 Gravity- 800 27.8 Original Canyon Reservoir Canyon riveted steel pressurized construction Penstock Hydro (1910) Betasso Boulder Betasso Welded 2900 feet 20 Gravity- 550 20 1964 (CML Pens[ock Canyon Hydro/ s[eeVCML pressurized added- Penstock Betasso 1985) WTF Boulder St. Vrain Boulder Open canal 13.2 miles NA Open channel NA 130 ~~ Maintained Feeder Canal Suppty Reservoid wi[h siphons on an Canal Boulder annual basis Res. WTF by NCWCD Source Water Master Plan Chapter 3 Page 3-31 Preliminary Draft August 12, 2007 Table : 2006 City of Boulder Hydroelectric Facility Summary Generatian 2006 Name Power/ Type of Capacity (kW) In-Service Generation 2006 Construction Pressure Turbine Make/Flow Date kWh Revenue Cost Zone 3 Reaction 80 kW Maxwell Treated Water (Fcaucis) General Elec[ric Mazoh 482,840 $21,366 S30Q000 Pum /Generator 110 si 200 ft. head 45 cfs 1985 Reac[ion Kohler Zone 3 (2 Francis) 135 kW November 140-240' Head Treated Water 140-240 ft Marathon XR[ 1986 797,120 $35,051 $526,000 I30 si. 113 si head 4 cfs Orodell TreatedWater Reaction 180kW September i40,400 518,600 $SA0,000 50' Head. Orodell Pipeline (Francis) Primeline 1987 250 si 240 si 413 tt head 7 cfs Sunshine TreatedWater Reaction 800kW September 3,049,600 $136,045 $1,100,000 750' Head. Sunshme Pipeline (Francis) Ununega-Hitachi 1986 325 si. 340 si 750 ft head 39 cfs $1,634,770 (includes Betasso Raw water Impulse 3,200 kW December 18,055,360 Lakewood E3,200,000 I,094' Head. Betasso Penstock (Pelton) Cumming Elec. 1987 (combined with and Silver 520 si. 550 si 1094 ft head 33 cfs Lakewood Lake SilverLake Rawwater Impulse 3,200kW March 11,52Q214 SeeBetasso $4,426,503 1,406' Head. Silver Lake Pipeline (Pelton) Alcouza 1998 630 s~. 663 si 1406 ft head 32 cfs August Boulder Cany. Raw water Impulse IQ000 kW 1910 11,451,441 $283,543 $3,OOQ000 1,847' Head. KosslerBarker (Pel[on1847 ft General Elec[ric (Purchased 840 si. 794 si head 75 cfs March 2001) Lakewood Raw water Impulse 3,400 kW June See Betasso $S,OOQ000 1,554' Head. Lakewood Pipeline (Pelton) Alconza 2004 Included with 730 si. 800 si 1554 ft head 32 cfs Betuso Total 21,796 kW 40,966,550 kWh $2,129,376 Total generation by all units since beginning operation has been 384,714,331 kWh. This has displaced the need to bum 192,537 tons of coal. Total revenue through 2006 was $I8,697,837. Source Water Master Plan Chapter 3 Page 3-32 Preliminary Draft August 12, 2007 The amount of water that the city derives from the water rights for each of its municipal water supply sources vazies from yeaz to year based on several factors including hydrolog}c conditions in each water basin and storage levels in the city's reservoirs. The delivery of water to the city under these rights may, at times, be further limited by the physical capacity of the ciTy's conveyance, storage and treatment facilities and by the actual need for water in the city. On average over the course of a yeaz, under the present level of water demands in the city, approximately 35 percent of the city's municipal water supply is diverted from the North Boulder Creek basin, approximately 35 percent is diver[ed from the Middle Boulder Creek basin, and approximately 30 percent is direct use of water from the CBT and Windy Gap projects. CBT and Windy Gap water can also be used indirecUy as an exchange source for some of the diversions from North Boulder and Middle Boulder Creeks when the native basin water rights would otherwise be out of priority. Therefore, a portion of the diversioas from Middle and Nor[h Boulder Creeks could not occur without the availability of CBT and Windy Gap water. The combined direct and indirect use of CBT and Windy Gap water transported from the westem slope supports 50 percent ofthe city's annual diversions on average with the other 50 percent derived from use of native basin water rights. 3.3.1. City of Boulder Municipal Water Rights In order for the city to diver[ water at any of the vazious diversion points in the Boulder Creek basin, the city must own a water right that is in priority to take water at the time. If downstream water users have more senior water rights that are not being satisfied, the ciTy must either allow water to pass its diversion points or meet the water rights call with water exchanged from another source. The city keeps a daily record of the diversion amounts at each municipal water system diversion or storage loca6on and records the associated water right that allows the water to legally be taken. These records are then submitted to the State E~gineer's Office which is responsible for administering all water diversioas and water righu in Colorado. The city maintains reliable water supplies through drought periods by filling its upper Boulder Creek reservoirs to the greatest extent possible during the high spring runoff period in most yeazs. The ciry typically has a four- to eight- week period each yeaz during high streamflow in the late spring to store the reservoir water supplies that will help carry the city through the e~tire upcoming yeaz. The combination of the city's native basin water storage rights and exchange rights assures that the city's reservoirs will fill by mid-June in almost every yeaz with sufficient sVeamflow in the upper Boulder Creek watershed. Use of the city's exchange water rights is necessary in some years to fill the upper Boulder Creek reservoirs when the native basin water storage rights aze called out of priority. When exchanging, the city trades water from Boulder Reservoir, Baseline Reservoir, the Lower Boulder Ditch or North Boulder Fazmers Ditch for additional water at the city's upper Boulder Creek intakes. 3.3.1.1. Direct Flow Rights The city's most senior direct flow municipal rights, amounting to about 45 cfs when in full priority, are derived from shazes in irrigation ditches located in the Boulder Valley (e.g. Anderson, Fanners, Hazden, Smith & Goss, and McCar[y). The city purchased shazes from prior agriculttval water users, changed the water rights to municipal use, and moved the diversion points upstream to the ciry's facilities on Middle and North Boulder Creeks. These changed irrigation rights may be used only during the inigation season to reflect their original pattern of use. The city also owns direct flow rights that were originally decreed for municipal use totaling about 86 cfs when in full prioriTy. Since the original use of the rights was for municipal purposes, they have a history of year-round water use and can be taken at any time of yeaz. However, they aze decreed for direct use only and cannot be stored after diversion for later use. The city's most senior yeaz-round direct flow water right is the Town of Boulder Ditch (62 cfs), which is normal]y in prioriry all winter. However, Source Water Master Plan Chapter 3 Page 333 Preliminary Draft August 12, 2007 during low flow winter months, the physical supply in the creek is oRen the limiting factor on how much water can be diverted. Table . Municipal Direct Flow Rights- Boulder Creek/North Boulder Creek/Middle Boulder Creek Water RI ht Amount Adjudication Date Appropriatlon Date Administration Number Case No. Anderson D~tch 3.50 cis 06-02-1882 10-01-7860 3927.00000 8407 Antlerson Ditch 2.67 cfs 06-02-1882 10-01-1860 3927.00000 10508 Anderson Ditch 5.83 cfs 06-02-1882 10-01-1860 3927.00000 15012 Anderson Ditch" t Bt cfs 06-02-1882 10-01-1860 3927.00000 W-7570 Anderson Ditch`• 0.59 cfs 06-02-1882 10-01-1860 3927.00000 90CW193 Boulder Ci Pi eline No 3 50.00 cfs 03-04-1964 OS-15-7956 40740.38851 82CW83 W-76 Boultler City Pipeline, Head ate No. 3 10.00 cfs 09-28-1953 12-31-1947 35793.00000 12111 Boulder Gity Pipeline, Head ates No. 1 8 2 20.00 cfs 71-03-1909 02-09-1904 19762.00000 5563 Farmers Ditch 5.57 cfs 06-02-1882 10-01-1862 4657 00000 8407 Fartners Ditch 4.88 cfs 06-02-1882 10-01-1862 4657 00000 10508 Fartners Ditch 4.14 cfs 06-02-1882 10-07-1862 4657 00000 15012 Farmers Oitch° 73.52 cfs 06-02-1882 10-01-1862 4657.00000 W-7569 Harden Ditch" 1.80 cfs 06-02-1882 06-01-1862 4535.00000 W-8520 Howell DRCh 7' Enlar ement"' 35.00 cfs 1231-1979 09-25-1979 47384.00000 79CW363 Howell Ditch 1` Enlar emenY" 2.00 cfs 12-31-1979 09-25-1979 47384.00000 79C1Nd63 Lower Boulder Ditch 0.88 cfs 06-02-1882 10-01-1859 3561 00000 94CW284 Lower Boulder Ditch 4.31 cTs 06-02-1882 06-0t-187~ 7457.OOU00 94CN284 McCa ` 0.64 cfs 06-02-1882 06-01-1862 4535 00000 W-7570 McCa ` 0.03 cfs 06-02-1882 06-01-1862 4535 00000 90CW193 North Boulder Farmers Ditch 123 cis 06-02-1882 06-01-1862 4535.00000 94CWL85 North Boulder Farmers Ditch 4.26 cfs 06-02-1882 06-01-1863 4900 00000 94CW285 Smith & Goss Ditch" 0.40 cfs 06-02-1882 11-15-1859 3606.00000 W-7570 Smith 8 Goss Ditch•• 0.05 cts 06-02-1882 17-15-1859 3606.00000 90CW193 Town of Boulder Ditch 6.19 cis 06-02-1882 06-17-1875 9299.00000 W-70518 Notes ' Partial list Updated January 7, 2004. *' Use of rights conveyed to CWCB for ins[reazn Flow subject m terms of city/CWCB agreement reserving some usage ri~u by the city. '"• Conditional in whole or in part. 3.3.1..2 Storage Rights The city has storage rights on both Nodh and Middle Boulder Creeks, in Boulder Reservoir, and by virtue of ownership of shazes in the company that owns Baseline Reservoir. The North Boulder Creek storage rights, which amount to over 7,000 acre feet when fulfilled, are associated with Albion Lake, Goose Lake, Island Lake, the Green Lakes, and Silver Lake in the city-owned Silver Lake Watershed. These water rights aze sufficiently senior to produce a fairly reliable source of supply. In 1906, the city purchased Silver Lake and Island Lake from the Silver Lake Ditch and Reservoir Company. A copy ofthe deed is included in Appendix _. The city acquired the two reservoirs, the land surrounding the reservoirs, and "all water rights, storage rights, water decrees, reservoir decrees and filings, and future filings for water storage." Water storage rights for the two reservoirs were applied for after the city's purchase and were adjudicated by the Boulder District Court on Mazch 13, 1907 in Case No. 4842. These rights included an 8073 acre-foot storage right for Silver Lake Reservoir appropriated Source Water Master Plan Chapter 3 Page 3-34 Preliminary Draft August 12, 2007 on September 23, 1887, a 371.8 acre-foot storage right for Island Lake appropriated on July 15, 189Q a 8073 acre-foot refill right for Silver Lake Reservoir and a 371.8 acre-foot refill right for Island Lake Reservoic Both refill rights carried an appropriation date of September 3, 1906. The city has signed contracts with the Silver Lake Ditch and Reservoir Company to annually deliver a certain amount of storage water to the company's headgate on Boulder Creek. The city's Middle Boulder Creek storage rights aze associated with Bazker and Skyscraper reservoirs and amount to over 12,000 acre-feet of storage space. Although these storage righis aze relatively junior, Bazker Reservoir fills in most yeazs since the city's exchange rights can be used for continued storage when the junior water rights aze called out. The city owns about 13 percent of the shazes in the Base Line Land and Reservoir Company. The city uses Baseline Reservoir as a source of water for exchange to the upper Boulder Creek reservoirs and diversions points. When not needed for exchange, the Baseline water is leased to downstream fazmers as a supplemental water source. As the city's water system developed and new reservoirs were constructed, the city applied for new water storage rights. All of the city's storage rights aze absolute with the exception of a few conditional storage rights. The ciry owns the undeveloped Park Reservoir site located on the Caribou Creek tributary of North Boulder Creek, and holds a conditional storage right for the site. When the city purchased the site in ttYe 1960's, it acquired both title to the land and a 3000 acre-foot conditional water right for storage in the proposed Pazk Reservoir. This conditional right was most recently reviewed for due diligence3 by the Water CouR in Case No. 99CW090 with continuation of the right for the next diligence period until Mazch 31, 2010. The water right was appropriated on October 11, 1960 for irsigation, domestic, mechanical, sanitary, fire protection, municipal, fish propagation, recreation, storage reserve, re- regulation, and multiple uses. Water sources for Pazk Reservoir include Cazibou Creek, the south branch of Nor[h Boulder Creek, Horseshoe Creek, and a creek whose name is u~~known to Boulder. The city acquired conditional water rights for the Wittemyer Ponds when it purchased the property which is located along the north side oF Boulder Creek west of County Line Road. The city inte~ds to develop these gravel ponds to store reusable water. Along with the property rights, the city acquired a one-half interest in the Howell Ditch, a conditional water right for storage in the Wittemyer Ponds and conditional direct flow rights for the Howell Ditch 1" Enlazgement. The original direct flow right for the Howell Ditch is very senior, having been appropriated on December 1, 1859 for the amount of 47.55 cfs and designated as Priority No. 3 on Boulder Creek. However, the water right was later modified in Boulder District Court Case No. 10324 on February 17, t 941 to limit diversions into the ditch to no more than 5 cfs. The remainder of the decree was found to be abandoned due to non-use. The conditional storage water right was appropriated on September 25, 1979 for a total volume of 656.8 acre feet for the five ponds (Case No. 97CW 151). The conditional direct flow rights for the Howell Ditch 1" Enlazgement were appropriated on September 25, 1979 for an amount of 37 cfs (Case No. 97CW 151). The decree provisions of the conditional water rights have not been implemented and the ponds operate under the grandfathering exemption from augmentation requirements. Finally, the ciry holds a conditional right for Barker Reservoir storage that was filed in 1999 just prior to the city's purchase of the facility. Source Water Master Plan Chapter 3 Page 3-35 Preliminary Draft August 12, 2007 Table .Municipal Storage Rig6ts - Boulder Creek/North Boulder Creek/Middle Boulder CreeWSouth Boulder Creek Water Ri ht Amount Adjutlication Date ApproprWtion Date Administration Number Case No. Albion Lake 1110.94 af 06-21-1926 07-01-1970 22096.00000 6672 Barker Meadow Reservoir 4000.00 af 03-04-1964 05-15-1956 40740.38851 W-2359-72 Barker Meadow Reservoir" 4000.00 af 12-31-7972 04-22-1966 44559.42480 W-2361-72, -79 Barker Meadow Reservoir"" 11,868 af 1999 Baseline Reservoir (75.938 of 553 shares 2929.90 aT 06-21-1926 11-04-1904 2089020031 6672 Baseline Reservoir (75.938 of 553 shares 1671.70 af 01-09-7935 11-29-1922 26630.00000 6672 Baseline Reservoir (75.938 of 553 shares 847.00 af 09-28-1953 1130-1935 31379 12111 Baseline Reservoir (75.938 of 553 shares 7395.00 af 09-28-1953 1231-1929 29219.00000 12111 Goose Lake 198.50 af 03-13-1907 10-01-1901 78901.00000 4842 Goose Lake 26120 af 03-13-1907 09-03-1906 20699.00000 4842 Goose Lake 576.60 af 11-03-1909 09-03-7906 20699.00000 5563 Green Lake No. 1 183.30 af 06-21-1926 10-02-1906 2089020728 6672 Green Lake No. 1 14 07 af 09-28-1953 10-02-1906 2089020728 6672 Green Lake No. 2 57.48 af 06-21-1926 10-02-1906 2089020728 6672 Green Lake No.2 82 49 af 09-28-1953 10-02-1906 20890.20728 12111 Green Lake No. 2 192.71 af 09-28-1953 10-02-1906 2089020728 12111 Green Lake No. 3 248.84 ai 06-21-1926 10-02-1906 2089020728 6672 Island Lake 371.80 af 03-13-1907 07-15-1890 20188.74806 4842 Island Lake Refill 371.80 af 03-13-1907 09-03-1906 20699.00000 4842 Park Reservoir"' 3000.00 af 03-04-1964 10-11-1960 40740 40461 14622 Silver Lake Reservoir 807.30 af 03-13-1907 09-23-1887 78615.13780 4842 Silver Lake Reservoir 322.7~ af 09-28-1953 09-061928 28738.00~00 121 t t Silver Lake Reservoir" 3020.00 af 09-28-7953 12-31-1941 33602 00000 12111 Silver Lake Reservoir Refill 807.30 af 03-13-1907 09-03-1906 20699 00000 4842 Sk scra er Reservoir 146.40 af 09-28-1953 07-24-1940 33077 12711 Wittem er Pond No. 1"' 100.80 af 1231-1979 09-25-1979 47384 00000 79CW363 Wittem er Pontl No 2"" 194.60 af 12-31-1979 09-25-1979 47384 00000 79CW363 Wittem er Pond No. 3•" 182.70 af 12-31-1979 09-25-1979 47384.00000 79CVY363 Wittem er Pond No. 4"' 80.70 af 12-31-1979 09-25-1979 47384 00000 79CVJ363 Wittem er Pond No. 5••• 97.90 af 12-31-1979 09-25-1979 47384.00000 79CWJ63 Notes: • Partial list. Updated 7anuary 7, 2004. " Usable by CWCB for instream tlow subjec[ [o [erms of c~ty/CWCB agreemen[ and at city discretion **" Condi[ional in whole or in part. 3.3.1.3 Exchange Rights The city's exchange rights allow the city to continue taking water at its upper Boulder Creek diversion points if its native basin rights have been called out by releasing water to more senior water rights owners from other sources. For the city's river exchanges, water can be released to Boulder Creek from Boulder Reservoir, Baseline Reservoir, or at the headgates of two ditches on Boulder Creek in which the city owns shares. One of the city's most important water rights allows exchange of up to 250 cfs from Boulder and Baseline Reservoirs to its diversion points on upper Boulder Creek. The ciry also has an"i~temal exchange" agreement with the Boulder and White Rock Ditch Company that allows the city to release water to the ditch from Boulder Reservoir in order to reduce the amount of water that would otherwise have to bypass ' In order to continue the existence of a conditional water right, it is necessary to obtain a finding by the Water Court every six years that the development of the necessary facilities and factors to make use of the conditional water right has oroceeded with due dilieence. Source Water Master Plan Chapter 3 Page 3-36 Preliminary Draft August12,2007 the city's reservoirs to meet the company's water demands at its headgate on Boulder Creek. The exchanges allow the city to continue diversions of an amount of water at the city's upper Boulder Creek diversions points, such as at Bazker, Lakewood and Silver Lake Reservoirs, that is equal to the amount of exchange water released by the ciry lower on the river. The ciry's Baseline Reservoir water, North Boulder Farmers Ditch water, and Lower Boulder Ditch water can only be used as a source of exchange water since their diversion points aze located downstream of the city's water treatrnent facilities. The city can exchange water into storage in its upper reservoirs or can exchange for direct flow into the raw water pipelines feeding Betasso WTF. Exchanges typically can occur during an exchange season that is almost entirely limited to higher flow periods on the creek. This is also when, in many years, the ciry's reservoirs aze most likely to be filling under their native basin water rights and the city's senior direct flow righu may be yielding enough to fill the city's pipelines without use of exchange. Therefore, water exchanges are used only when needed because the city's native basin water rights have been called out of prioriTy. The total aru~ual amount of water exchanged for direct flow use during 285 modeled yeazs of system operation ranged from 302 acre-feet to 2542 acre-feet and averaged 1854 acre-feet. The total annual amount of water exchanged for reservoir storage during 285 modeled yeazs of system operation ranged from 108 acre-feet to 9463 acre-feet and averaged 2688 acre-feet. The amount exchanged compared to the amount of city water supplied by native basin rights, CBT, and Windy Gap is shown in Figure anc below. Exchanges help to maintain the carry-over water levels in the ciry's Boulder Creek reservoirs that protect against major water shortages during drought periods. Additional water can be taken into storage during higher flow yeazs for carrying forwazd into Iower flow yeazs. The city could not meet the established water system reliability criteria without use of the exchange rights. If seniot water rights calls from lower on Boulder Creek or from the South Platte occur during the spring reservoir filling period, the city's reservoir storage rights will be called out. The exchange mechanism is used to continue storing in the reservoirs during the critical high flow period when water is physically available at the high mountain reservoir diversion points by satisfying other water rights with an alternative supply such as CBT. Only water rights calls coming from a point below the discharge out of Boulder Reservoir can be satisfied in this mannec Senior calls occurring above this point on the river must be answered by aliowing wate~ to pass by the city's storage reservoirs. Efforts aze made to store as much water as possible during the high spring runoff because streamflows quickly drop to typical summer levels that are too low to allow the city to store water in its reservoirs either under its native basin rights or through exchange. The exchange righu ue frequently limited by the physical flow in Boulder Creek in the intervening portions of the stream between the city's diversion points and the downstream senior rights. No hazm is allowed to occur to intervening rights that are senior to the exchange decree, which includes several active rights on Boulder Creek. River conditions at any partiwlaz time create what is known as the "exchange potential ° The exchange potential on Boulder Creek vazies from yeaz to year and season to season based on the call for water by other water right owners. The city's ability to exchange water is limited by the lack of exchange potential on the river during most times of the yeaz. For example, the amount needed to satisfy senior ditch rights on Boulder Creek from just west of Boulder to 75'" Sheet is typically in the range of 170 cfs during the summer. Therefore, the city can usually only exchange water for continued diversioas into Barker Reservoir when there is enough flow into and out of Bazker Reservoir to maintain more than 170 cfs for the downstream calls above 75`" Street. Sometimes there is enough water in the creek that water can be exchanged for direct diversion into the city's upper pipelines as well as into storage. However, under the Source Water Master Plan Chapter 3 Page 3-37 Preliminary Draft August 12, 2007 city's agreements with the Colorado Water Conservation Boazd, exchanges are also limited at times that Boulder Creek flows below Orodell aze Iess than 15 cfs. The city's use of exchanges occurs mostly during high streamflow periods. Exchanges do not usually occur during low flow periods in the late summer and winter due to limited water physically available in the stream for diversion by the ciTy and water demands by other water users that cannot be satisfied with an exchanged supply. In addition, the city's agreements with the Colorado Water Conservation Board state that exchanges will be curtailed when streamflows below Orodell drop below 15 cfs. Another limitation to the ciry's exchange is the physical space available in the Boulder Creek Supply CanaL The ciry has a guazanteed right to use up to 90 cfs of the canal's 200 cfs capacity for its exchange. It may use more than 90 cfs only if it is not needed by others. Therefore, including Utilities' S0 cfs exchange right out of Baseline Reservoir, the city's total exchange capabiliry can be limited to 140 cfs at certain times. Table . Municipal Exchange Rights" - Boulder Creek Adjudication AppropNation Adminiatratio Water Ri ht Amount Date Date n Number Case No. Baseline Reservoir 57 shares - 50.00 cis 12-31-1974 12-31-1954 38350.00000 W-7852-74 Boulder Ck. 6cchan e CBT in Boulder Reservoir- 200 00 cfs 72-31-1974 12-31-1954 38350.00000 W-7852-74 Boulder Ck. Exchan e NoAh Boulder Farmers - Boulder 4.50 cfs 12-31-7994 12-29-1994 52958.00000 94CVJ285 Ck. Exchan e"' Lower Boulder Dilch ~change 2.14 cts 12-31-1994 1230-1993 52795.00000 94CW284 Boultler Creek Fartns "' Lower Boulder Ditch Exchange 3.05 cfs 1231-1994 07-19-1994 52795.00000 94CW284 Hummel "' Baseline Reservoir ~ooc shares - 50.00 cfs 12-31-1994 12-30-1993 52795.00000 94CW264 BoulderCk.Exchan e"" Windy Gap in Boulder Reservoir- 2000 Boulder Creek Exchan e"' Notes: ' Partial list. Updaced January 7, 2004. **• Condi[ional in whole or in part. 3.3.2 Water Contracts Boulder Reservoir can be filled with water from the Colorado-Big Thompson Project and the Windy Gap Project. Boulder is also entitled to a portion of the water derived from an agreement between Northern Colorado Water Conservancy District and the Lefr Hand Water District known as the "20% Water". In addition, Farmers' Ditch water associated with some of the city's shaze ownership in the ditch company is allowed to be carried t}uough the reservou for direct use at the Boulder Reservoir Water Treatment Facility at times when the water is not needed by the Colorado Water Conservation Board to provide instream flows in Boulder Creek. Table. Municipal Trans-mountain Water Rights Delivered at Boulder Reservoir* Water Ri ht Amount Colorado-Bi Thom son 21,015 units Wnd Ga 37umts Source Water Master Plan Chapter 3 Page 3-38 Preliminary Draft August12,2007 3.3.2.1 Colorado-Big Thompson Project Water The CBT Project collects and stores the water of the upper Colorado River for subsequent delivery to water users in northeast Colorado. The majoriry of CBT Project facilities and all of its water rights aze owned by the Bureau of Reclamation which built the project. The remainder of the facilities is owned by NCWCD which operates the project. NCWCD delivers CBT water to the entities with which it has water delivery contracts, called allottees, or to lessees of the allottees. CBT facilities located west of the Continental Divide include Willow Creek and Shadow Mountain Reservoirs, Grand Lake and Lake Granby. The water is pumped into Shadow Mountain Reservoir where it flows by gravity into Grand Lake. From there, the 13.1 mile Alva B. Adams Tunnel transports the water under the divide to the East Slope. Once the water reaches the East Slope, it is used to generate electriciry as it falls almost half a mile through five power plants on its way to Colorado's Front Range. Carter Lake, Horsetooth Reservoir and Bouldet Reservoir store the water. CBT water is released as needed to supplement native water supplies in the South Platte River basia The CBT Project delivers on average 213,000 acre feet of water annually to northeastem Colorado for agticultural, municipal and industrial uses. CBT projec[ facilities aze shown on Figure _ Carter Lake is the main reservoir feeding the southern end of the CBT system. CaRer Lake water is delivered to cities and agricultural users in Boulder, Lazimer, Weld and Broomfield Counties. Water from the Carter Lake is carried to Boulder Reservoir through the St. Vrain Feeder Canal and the Boulder Feeder Cana1. The two canals comprise a part of the 98-mile network of canals within the CBT Project. Although officially designated as rivo sepazately named canals, the entire reach from Carter Lake to Boulder Reservoir is often referred to just by the name Boulder Feeder Canal. NCWCD allottees own units of the CBT Project which entitle them to water deliveries based on the quota set by the NCWCD Boazd every yeaz. Each unit may receive up to one acre foot of water per unit which is defined as a 100percent quota. Quotas are usually set higher in dry yeazs for the South Platte River basin and lower in wet years because CBT water is considered to be supplemental to native basin water supplies. The city Water Utility holds 21,015 units out of 315,000 units total in the CBT project. Modeling of the CBT system has projected that it can deliver a 100 percent quota throughout a drought period similaz to the 1950's. The quota in the severe drought year of 2002 was set at 70 percent due to low water levels in the CBT system reservoirs. 3.3.2.2 Windy Gap Project Water Windy Gap Reservoir is located just west of the Town of Granby on Colorado's Western Slope. The Windy Gap Project consists of a diversion dam on the Colorado River that creates the 445-foot Windy Gap Reservoir, a pumping plant, and a six-mile pipeline to Lake Granby. The system was anticipated to deliver an average of 48,000 acre-feet of water annually, diveRed primarily dwing the spring runoff season between April and July. During these periods of high flows in the Colorado and Fraser Rivers, water is pumped from Windy Gap Reservoir to Lake Granby, where it is stored for delivery through the Colorado-Big Thompson (CBT) Project facilities to water users on the Front Range. ConsVUCtion of the project began in 1981 and the facilities became operational in the spring of 1985. After studying growth rates and water supply and demand projections, a coalition of six Front Range cities - Boulder, Estes Pazk, Fort Collins, Greeley, Longmont and Loveland - concluded that it would be ^ecessary to develop a water supply project specifically to meet municipal needs. The cities eventually settled on the concept that would lead to the development of the Windy Gap trans-mountain diversion project to meet those needs. In 1969 the six cities realized that the amount of work and expertise necessary to build the Windy Gap Project required a stronger organization than they could provide Source Water Master Plan Chapter 3 Page 3-39 Preliminary Draft August 12, 2007 independently. They subsequently petitioned the District Court in Greeley for the formation of a Municipal Subdistrict with the NCWCD. The court approved formation of the Subdistrict on July 6, 1970 (Municipal Subdistrict, NCWCD). After its formation, the Subdisffict negotiated a Carriage Contract with the U.S. Bureau of Reclamation and NCWCD specifying how Windy Gap water would be stored and carried to the Eastem Siope cities through the CBT project. The Carriage Contract executed in October 1973 was a crucial first step in the development of Windy Gap. With the ability to use excess capacity ofthe existing CBT storage and conveyance facilities, the project is economically and environmentally viable. Lengthy litigation and environmental impact assessment and mitigation processes ensued. Litigation terminated with the 1980 Windy Gap Settlement Agreement. In the summer of 1975, the Subdistrict entered into water allotment contracts with each of its six member cities. Each retained a one-sixth shaze in the project. The allotment contracts provide that participants annually receive their proportional shaze of Windy Gap watec Every unit equals ]00 acre-feet of water, or 1/480 of the annual average yield produced. Each water allotment contract requires participants to make annual payments equal to the corresponding shaze of the costs related to the SubdistricYs acquisition of water rights, and operation, maintenance and replacement of Windy Gap Project features, as well as carriage charges to the NCWCD and USBR for using the CBT Project for storing and delivering Windy Gap water. With Subdishict Boazd approval, participants may transfer all or part of their water allotment to another entity within the Subdistrict. In 1975, the Platte River Power Authority acquired one-half of the Loveland and Estes Pazk allotments as well as all of the water designated for Fort Collins. Five additional water suppliers have since become Windy Gap Project participants. Broomfield pumhased 43 of Boulders units and Louisville, Superior, the Left Hand Water District and the Central Weld County Water District have also acquired allotments. A benefit to Subdistrict allottees is that allotment contract holders aze granted total consumptive use of their Windy Gap water. Allottees can use and reuse Windy Gap water because it is imported water not native to the South Platte Basin. After first use within Subdistrict boundazies, participants may lease, transfer or sell the reuse or successive use rights for use within or outside Subdistrict boundaries. A supplemental agreement was reached in 1985, which led to construction of Wolford Mountain Reservoir by the Colorado River Water Conservancy District as a Western Slope storage project. Wolford Mountain Reservoir was completed in 1995 (Municipal Subdistrict, NCWCD). 3.3.2.3 Lej'1 Hand "20% Water" In 1963, NC WCD signed an agreement with Left Hand Ditch Company permitting Left Hand to divert water from Lefr Hand Creek into the Boulder Feeder Canal in exchange for CBT water to be taken by Left Hand at an upstream point later in the yeaz. Water diverted by Lefr Hand into the Boulder Feeder Canal was accounted for as being stored in Boulder Reservoir. NCWCD performs the o~cial accounting for water stored in Boulder Reservoir and, each year, NC WCD kept the difference in the amount of water diverted into the Boulder Feeder Canal by Left Hand and the lesser amount of water delivered by the District to Left Hand. Boulder objected to this practice because the additional yield to NCWCD was made possible through the use of storage space in Boulder Reservoir and the city owns the reservoir. The agreements that were in place did not allow NCWCD to grant use of Boulder Reservoir storage space to other users. Source Water Master Plan Chapter 3 Page 3-40 Preliminary Draft August12,2007 Negotiations were held, and in 1992, the city signed an agreement with NC WCD allowing the storage of Lefr Hand water in Boulder Reservoic Boulder consented to Left Hand Ditch Company's diversion of water into the Boulder Feeder Canal and storage of that water in any available space in Boulder Reservoir. In retum, each yeaz Boulder receives 20 percent of the difference between the amount of water provided by Left Hand apd the amount of water delivered to Left Hacid by NCWCD. The "20% water" is accounted for as being the first water used by Boulder out of Boulder Reservoir every year, prior to the city's use of any CBT water. 3.3.2.4 Municipal Use of Instream F[ow Water The city conveyed use of certain senior water rights and of storage water deliveries to the C WCB in 1990 and 1992 to assist the Boazd in maintaining instream flow. The conveyed water was derived from shazes in ditch companies including Farmers Ditch, Anderson Ditch, Smith and Goss Ditch, McCarty Ditch, and Hazden Ditch. Most of the shazes had previously been changed to allow municipal use, but a portion were still decreed for the original agricultural use. All of the water was taken through a Water Court proceeding that resulted in a decree allowing both municipal and instream flow use of the water. 3.3.2.4./ Use of Ditch Shares The city can use the conveyed water for municipal needs when it is not needed to maintain icistream flow levels. In addition, the city has the right to use, re-use, or lease the poRion of the conveyed water that had historically been consumed through municipal use by the city once that water reaches 75~' Street and has served its instream flow purpose. 3.3.2.4.2 Drought or Emergency Interruption Under the city/CWCB agreements, the city may use the conveyed watet rights for municipal pwposes in the event of extraordinary drought or emergency conditions. The city exetcised this right of reversion during the drought yeaz of 2002 and used the conveyed water to meet municipal needs. Source Water Master Plan Chapter 3 Page 3-41