HomeMy WebLinkAboutSource Water Master Plan Volume 2City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page i
Table of Contents
1 | INTRODUCTION.....................................................................................................................1-1
1.1 | Source Water System Overview.........................................................................................................1-1
1.2 | Source Water Master Plan Contents..................................................................................................1-1
2 | PURPOSE AND SCOPE...........................................................................................................2-1
2.1 | Purpose of the Source Water Master Plan.......................................................................................2-1
2.2 | Previous Raw Water Master Plan.......................................................................................................2-1
2.3 | Scope of the Source Water Master Plan..........................................................................................2-4
3 | MANAGEMENT OF BOULDER’S WATER SUPPLY ...................................................................3-1
3.1 | Management of Boulder’s Raw Water System................................................................................3-1
3.2 | Historical Factors Affecting Water Management............................................................................3-2
3.2.1 | History of Colorado Water Development..........................................................................3-2
3.2.2 | Development of City Water Supplies..................................................................................3-4
3.3 | Management of Irrigation Ditches....................................................................................................3-18
3.3.1 | Irrigation Ditch Background .................................................................................................3-18
3.3.2 | Maintenance of Irrigation Ditches.......................................................................................3-20
3.3.3 | Irrigation Ditches and Urban Encroachment......................................................................3-20
3.3.4 | Stormwater and Irrigation Ditches......................................................................................3-21
3.4 | Legal Factors Affecting Water Management................................................................................3-23
3.4.1 | Colorado Water Law............................................................................................................3-23
3.4.2 | Water Utility Enterprise Fund..............................................................................................3-26
3.4.3 | Safe Drinking Water Act......................................................................................................3-29
3.4.4 | Source Water Assessment and Protection Program........................................................3-29
3.4.5 | Federal Energy Regulatory Commission............................................................................3-30
3.4.6 | Colorado River Compact......................................................................................................3-31
3.4.7 | City Code................................................................................................................................3-33
3.4.8 | Boulder Valley Comprehensive Plan..................................................................................3-34
3.4.9 | Contracts..................................................................................................................................3-35
3.4.10 | Water and District court cases..........................................................................................3-60
3.5 | Operational Considerations for Water Management..................................................................3-64
3.5.1 | Management of City Water Rights....................................................................................3-65
3.5.2 | Operational “Seasons”.........................................................................................................3-66
3.5.3 | Reservoir Management.........................................................................................................3-67
3.5.4 | Management of Exchanges..................................................................................................3-69
3.5.5 | Instream Flow Effects on Management of City Water Supplies...................................3-71
3.5.6 | Management of Hydro Operations....................................................................................3-71
3.5.7 | Management of Surplus Water Leasing............................................................................3-75
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3.6 | Supporting Studies and Information.................................................................................................3-76
3.6.1 | 1988 Raw Water Master Plan...........................................................................................3-76
3.6.2 | Drought Plan...........................................................................................................................3-78
3.6.3 | Additional Plans and Studies...............................................................................................3-78
4 | RAW WATER SUPPLY SYSTEM ASSETS................................................................................... 4-1
4.1 | Land...........................................................................................................................................................4-1
4.1.1 | Silver Lake Watershed............................................................................................................4-1
4.1.2 | Park Reservoir Dam Site..........................................................................................................4-3
4.1.3 | Lakewood Reservoir Site and Lakewood House.................................................................4-3
4.1.4 | Caribou Ranch...........................................................................................................................4-4
4.1.5 | Barker System...........................................................................................................................4-5
4.1.6 | Water Source Operations Manager’s House......................................................................4-6
4.1.7 | Betasso Water Treatment Facility Site and Betasso Penstock Corridor.........................4-6
4.1.8 | Orodell Hydro Plant Site (Blanchard Intake) ......................................................................4-6
4.1.9 | Sunshine Reservoir Site............................................................................................................4-8
4.1.10 | Boulder Reservoir Lands........................................................................................................4-8
4.1.11 | Wittemyer Ponds.................................................................................................................4-11
4.2 | Municipal Water Supply Infrastructure...........................................................................................4-13
4.2.1 | North Boulder Creek Water Facilities...............................................................................4-13
4.2.2 | Middle Boulder Creek/Barker Reservoir Water Facilities............................................4-26
4.2.3 | Betasso Facilities Complex and Small Hydros..................................................................4-32
4.2.4 | Boulder Reservoir Raw Water Facilities............................................................................4-33
4.2.5 | Farmers Ditch..........................................................................................................................4-36
4.2.6 | Boulder Reservoir Water Treatment Facility at 63rd Street..........................................4-36
4.3 | Water Rights and Water Contracts.................................................................................................4-41
4.3.1 | City of Boulder Municipal Water Rights...........................................................................4-41
4.3.2 | Water Contracts....................................................................................................................4-49
5 | WATER USE, AVAILABILITY AND QUALITY........................................................................... 5-1
5.1 | Water Use................................................................................................................................................5-1
5.1.1 | Treated Water Use..................................................................................................................5-1
5.1.2 | Raw Water Irrigation Use....................................................................................................5-19
5.1.3 | Instream Flow Use..................................................................................................................5-20
5.1.4 | Flow-Based Recreation.........................................................................................................5-33
5.2 | Hydrology.............................................................................................................................................5-34
5.2.1 | Factors Affecting Hydrology...............................................................................................5-34
5.2.2 | Historic Hydrology of the Boulder Creek Basin...............................................................5-42
5.2.3 | Historic Hydrology of the Upper Colorado River Basin.................................................5-52
5.2.4 | Development of Natural Streamflow Hydrologic Data .................................................5-53
5.2.5 | Droughts in the Historic Record ...........................................................................................5-56
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5.2.6 | Hydrologic Trends Attributable to Climate Change........................................................5-60
5.3 | Municipal Water Rights Yields..........................................................................................................5-64
5.3.1 | Physical and Institutional Factors Affecting Yields...........................................................5-64
5.3.2 | Water Rights Yield Estimates...............................................................................................5-64
5.4 | Source Water Quality ........................................................................................................................5-73
5.4.1 | Source Water Quality Goals..............................................................................................5-74
5.4.2 | Ability to Meet Current Drinking Water Quality Standards.........................................5-74
5.4.3 | Source Water Characterizations........................................................................................5-78
5.4.4 | Current and Future Land Uses Affecting Water Quality................................................5-80
5.4.5 | Source Water Quality Management.................................................................................5-85
6 | ISSUES ....................................................................................................................................6-1
6.1 | Water Management and System Operations Issues.......................................................................6-1
6.1.1 | Operational Flexibility ...........................................................................................................6-1
6.1.2 | Emergency Response Planning...............................................................................................6-6
6.1.3 | Maintenance and Staffing .....................................................................................................6-7
6.1.4 | Security, Remote Operation, and Monitoring.....................................................................6-8
6.2 | Water Rights Yield Issues.....................................................................................................................6-9
6.2.1 | Reliability Criteria ...................................................................................................................6-9
6.2.2 | Factors That Could Affect Water Rights Yield...................................................................6-9
6.2.3 | Yield Issues Resulting from Facilities Limitations...............................................................6-11
6.2.4 | Reliance on West Slope Water Supplies..........................................................................6-13
6.3 | Water Use Issues..................................................................................................................................6-13
6.3.1 | Municipal Water Demand Projections...............................................................................6-13
6.3.2 | Water Conservation..............................................................................................................6-13
6.3.3 | Non-Municipal and Non-Potable Uses...............................................................................6-14
6.4 | Watershed Management Issues........................................................................................................6-18
6.4.1 | Land Use Agreement and Easement Management Issues ..............................................6-18
6.4.2 | Contamination Sources..........................................................................................................6-20
6.4.3 | Invasive and Non-Native Species.......................................................................................6-26
6.4.4 | Wildland Fire .........................................................................................................................6-26
6.4.5 | Habitat Protection and Land Management Policies........................................................6-30
6.5 | Facilities Condition and Improvement Issues...................................................................................6-31
6.5.1 | North Boulder Creek Water Facilities................................................................................6-31
6.5.2 | Middle Boulder Creek / Barker Reservoir Water Facilities..........................................6-37
6.5.3 | Boulder Reservoir Raw Water Facilities............................................................................6-42
6.5.4 | Highest Priority Facilities Condition Issues.........................................................................6-44
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7 | RECOMMENDATIONS............................................................................................................7-1
7.1 | Policy Assessment and Recommendations...........................................................................................7-2
7.2 | Facilities Improvements..........................................................................................................................7-5
7.2.1 | Capital Improvement Projects................................................................................................7-5
7.2.2 | Minor Projects.........................................................................................................................7-13
7.3 | Programs...............................................................................................................................................7-16
REFERENCES.................................................................................................................................R-1
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page v
List of Tables
Table 3-1. Partial List of Irrigation Ditches Within the Boulder Valley...................................................3-18
Table 3-2. Summary of Facility-Specific Contract Terms...........................................................................3-50
Table 3-3. Capacity Test Revenue for Silver Lake, Lakewood, and Betasso Hydros..........................3-73
Table 3-4. Boulder Canyon Hydro Facts (2006) ........................................................................................3-74
Table 3-5. Water Rights Available for Agricultural Lease.......................................................................3-76
Table 4-1. Treated Water Unit Production Costs........................................................................................4-37
Table 4-2. City of Boulder Dam and Reservoir Summary Data...............................................................4-38
Table 4-3. City of Boulder Raw Water Pipeline, Penstock and Canal Summary.................................4-39
Table 4-4. City of Boulder Hydroelectric Facility Summary.....................................................................4-40
Table 4-5. Municipal Direct Flow Rights........................................................................................................4-42
Table 4-6. Municipal Storage Rights.............................................................................................................4-45
Table 4-7. Municipal Exchange Rights..........................................................................................................4-47
Table 4-8. Reuse Rights....................................................................................................................................4-48
Table 4-9. Summary of Boulder Canyon Hydroelectric Project Water Rights......................................4-48
Table 4-10. Municipal Western Slope Water Delivered at Boulder Reservoir....................................4-49
Table 4-11. Determination of NCWCD Deliveries to Left Hand Ditch Company.................................4-52
Table 5-1. Drought Reduction Goals for Types of Water Usage Drought Alert Stage......................5-12
Table 5-2. Historical and Projected Demand in Acre-Feet By Customer Class.....................................5-14
Table 5-3. Previous Population and Employment Projections...................................................................5-15
Table 5-4. 2008 Actual Boulder Service Area Population and Employment........................................5-16
Table 5-5. Desirable Minimum Instream Flow Levels..................................................................................5-23
Table 5-6. CWCB Water Rights for Instream Flow in Boulder Creek and Tributaries........................5-24
Table 5-7. City Water Rights Provided to the CWCB to Use for Instream Flow..................................5-26
Table 5-8. Streamflow Gages in the Boulder Creek Basin.......................................................................5-43
Table 5-9. USGS and CDWR Stream Flow Gages in the Upper Colorado River Basin.....................5-53
Table 5-10. Location of Reconstructed Natural Flows in Boulder Creek Basin......................................5-54
Table 5-11. Comparison of Significant Historical Droughts, Boulder Creek Near Orodell................5-58
Table 5-12. Boulder's Historical Municipal Water Rights Diversions and Storage Releases..............5-68
Table 5-13. Historical Municipal Water Deliveries by Source.................................................................5-69
Table 5-14. Potential Yield of Boulder's Municipal Water Rights and Supplies ..................................5-69
Table 5-15. City of Boulder Source Water Protection Goals..................................................................5-75
Table 6-1. Summary of Facility Condition and Critical Position in Water Supply................................6-44
Table 7-1: Source Water Policy Recommendations......................................................................................7-2
Table 7-2. List of Capital Improvement Projects and Priority.....................................................................7-6
Table 7-3. List of Minor Improvement Projects and Priority (Capital Cost Less Than $50,000)........7-14
Table 7-4. Recommended Source Water Programs and Studies............................................................7-16
Table 7-5. 20-Year Cip...................................................................................................................................7-23
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Final - April 2009 Page vi
List of Figures
Figure 3-1. Ditches within Boulder Valley.....................................................................................................3-19
Figure 3-2. Upper and Lower Basins Under the Colorado River Compact............................................3-32
Figure 3-3. Map of Caribou Ranch Properties............................................................................................3-47
Figure 3-4. Total Generation and Revenue for Boulder’s Hydros...........................................................3-72
Figure 3-5. Streamflow Increments at Orodell Delivered through Middle Boulder
Creek and through Boulder Canyon Hydro...........................................................................3-75
Figure 4-1. Land Acquisitions in the Silver Lake Watershed.......................................................................4-2
Figure 4-2. Location of Horseshoe Placer Mining Claim and Blanchard Intake......................................4-7
Figure 4-3. Location of Historic Town and Sunshine Reservoirs..................................................................4-9
Figure 4-4. Boulder Reservoir Land Ownership ..........................................................................................4-10
Figure 4-5: Wittemyer Ponds Property ........................................................................................................4-12
Figure 4-6. Map of Boulder’s Water Supply System.................................................................................4-14
Figure 4-7. Green Lake #1.............................................................................................................................4-15
Figure 4-8. Silver Lake Reservoir...................................................................................................................4-19
Figure 4-9. 1929 Silver Lake Outlet Pipe....................................................................................................4-20
Figure 4-10. Lakewood Reservoir..................................................................................................................4-23
Figure 4-11. Barker Reservoir........................................................................................................................4-27
Figure 4-12. Boulder Canyon Hydro.............................................................................................................4-30
Figure 4-13. Betasso and Lakewood Hydros ..............................................................................................4-32
Figure 4-14. Betasso Water Treatment Facility..........................................................................................4-33
Figure 4-15. Boulder Feeder Canal..............................................................................................................4-35
Figure 4-16. Boulder Reservoir Water Treatment Facility at 63rd Street..............................................4-37
Figure 4-17. Colorado-Big Thompson Project Facilities.............................................................................4-51
Figure 5-1. City of Boulder Treated Water Service Area..........................................................................5-2
Figure 5-2. Boulder’s 2007 Water Use by Type (%)..................................................................................5-3
Figure 5-3. Comparison of Indoor and Outdoor Use...................................................................................5-4
Figure 5-4. Indoor Use as a Percentage of Total Water Use....................................................................5-4
Figure 5-5. Boulder’s Total Treated Water Use, 1971-2007....................................................................5-5
Figure 5-6. Boulder’s Total Indoor Use, 1971-2007....................................................................................5-6
Figure 5-7. Boulder’s Total Outdoor Use, 1971 - 2007..............................................................................5-6
Figure 5-8. Comparison of Recent Use With Pre-2002 Drought Use.......................................................5-7
Figure 5-9. Water Use 2002-2007................................................................................................................5-7
Figure 5-10. Boulder’s Peak Day Use and Peak Ratio, 1971 - 2007......................................................5-8
Figure 5-11. Boulder’s Per Capita Use, 1971 - 2007.................................................................................5-9
Figure 5-12. Flow in Boulder Creek Between Orodell and 75th Street in 2006-2007......................5-27
Figure 5-13. Habitat Percentages in Middle Boulder Creek Study Area..............................................5-30
Figure 5-14. Stream Cross Section, Water Depth and Water Surface Elevations in Middle
Boulder Creek...........................................................................................................................5-30
Figure 5-15. Historical Stream Daily Mean Streamflow – Boulder Creek Near Orodell...................5-33
Figure 5-16. Annual Precipitation in Colorado............................................................................................5-36
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Final - April 2009 Page vii
Figure 5-17. Average Annual Water Runoff in Colorado........................................................................5-37
Figure 5-18. Average Annual Precipitation, Boulder Creek Headwaters..............................................5-39
Figure 5-19. Average Monthly Precipitation, Boulder Creek Headwaters............................................5-39
Figure 5-20. Average Snowpack Accumulation Patterns at Boulder Creek Snotel Sites.....................5-40
Figure 5-21. Prediction Value of Snowpack to Actual Boulder Creek Runoff Volume ........................5-40
Figure 5-22. 1894-2006 Annual Precipitation, City of Boulder..............................................................5-41
Figure 5-23. 1894-2006 Average Monthly Precipitation, City of Boulder...........................................5-42
Figure 5-24. Boulder Creek Watershed Natural Flow Production by Sub-Basin .................................5-42
Figure 5-25. Wet, Dry and Average Year Hydrographs - Middle Boulder Creek at Nederland...5-45
Figure 5-26. Middle Boulder Creek at Barker Reservoir, Water Year 1998.......................................5-46
Figure 5-27. Natural vs. Historical Flows, North Boulder Creek Below Lakewood Reservoir,
Water Year 1998....................................................................................................................5-48
Figure 5-28. Average Natural vs. Historical Flows, Boulder Creek Below Broadway,
1997-2006................................................................................................................................5-50
Figure 5-29. Tree Ring-Based Reconstruction of Annual Flows for Boulder Creek Near Orodell.....5-55
Figure 5-30. Natural Flow for Boulder Creek Near Orodell Reconstructed from Gage Records.....5-56
Figure 5-31. Flow Deficits and Duration of Major Droughts for Boulder Creek Near Orodell.........5-57
Figure 5-32. Reconstructed Natural Flow, Colorado River At Hot Sulphur Springs..............................5-58
Figure 5-33. Comparison of Natural Flows – Boulder Creek vs. Colorado River.................................5-59
Figure 5-34. Significant Droughts as Evidenced by Tree Rings, Boulder Creek Near Orodell..........5-60
Figure 5-35. Dates of Peak Daily Flow, Middle Boulder Creek at Nederland ....................................5-61
Figure 5-36. Annual Flow Volumes, Middle Boulder Creek at Nederland.............................................5-61
Figure 5-37. Summary of Boulder’s Historical Municipal Deliveries by Source.....................................5-66
Figure 5-38. Potential Yield of Boulder's Municipal Water Rights and Supplies .................................5-66
Figure 5-39. Water Demand Levels at Build-Out Compared to Boulder’s Water Supply.................5-70
Figure 5-40. Land Use and Potential Water Contamination Sources Near Barker Reservoir............5-82
Figure 5-41. Outfalls to Boulder Feeder Canal..........................................................................................5-85
Figure 6-1. City of Boulder Modeled Water System Operations With and Without Exchanges:
Minimum Storage Level in Upper Boulder Creek Reservoirs................................................6-4
Figure 6-2. Boulder Creek Streamflow at Orodell With and Without Exchanges in 2000 .................6-5
Figure 6-3. Average Annual Modeled Production at Boulder Reservoir Water Treatment Facility
With and Without Exchanges.....................................................................................................6-6
Figure 6-4. South Boulder Creek Mean Daily Flows Compared to Instream Flow Need....................6-16
Figure 6-5. North Boulder Creek Sources of Contamination.....................................................................6-21
Figure 6-6. Middle Boulder Creek Sources of Contamination..................................................................6-22
Figure 6-7. Boulder Feeder Canal Sources of Contamination..................................................................6-25
Figure 6-8. North Boulder Creek Wildland Fire Risk.................................................................................6-27
Figure 6-9. Middle Boulder Creek Wildland Fire Risk...............................................................................6-28
Figure 6-10. Boulder Reservoir Watershed Wildland Fire Risk...............................................................6-29
Figure 6-11. Boulder Feeder Canal Watershed Wildland Fire Risk.......................................................6-29
Figure 6-12. Albion Dam Upstream Face.....................................................................................................6-32
Figure 6-13. Albion Dam Valve House..........................................................................................................6-32
Figure 6-14. Spalling and Cracking Along Upstream Face of Albion Dam...........................................6-33
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Final - April 2009 Page viii
Figure 6-15. Exposed Reinforcement on Upstream Face of Albion Dam...............................................6-33
Figure 6-16. Goose Lake Dam.......................................................................................................................6-34
Figure 6-17. Island Dam Debris Buildup And Leak.....................................................................................6-35
Figure 6-18. Seepage through Skyscraper Dam and Bent Outlet Gate Stem.....................................6-37
Figure 6-19. Barker Dam Downstream Face ...............................................................................................6-38
Figure 6-20. Barker Dam Anchor...................................................................................................................6-39
Figure 6-21. Flume Downstream of Barker Dam.........................................................................................6-40
Figure 6-22. Barker Gravity Outlet to Kossler Reservoir..........................................................................6-40
Figure 6-23. Kossler Main Dam Upstream Face .........................................................................................6-41
Figure 6-24. Kossler Reservoir Gate House and Outlet Forebay............................................................6-42
Figure 6-25. Platform at Boulder Feeder Canal Inlet to Boulder Reservoir WTF.................................6-43
Figure 7-1. Installation of Geotextile and Membrane Over Masonry Face Dam..................................7-8
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 1-1
Chapter 1
1 | INTRODUCTION
1.1 | Source Water System Overview
Boulder’s water supply system includes many storage, conveyance, hydroelectric and treatment
facilities. The city owns approximately 7,200 acre-feet of reservoir storage space in the North
Boulder Creek watershed, owns 11,700 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 are the Betasso Water Treatment Facility (WTF), with approximately 45 million
gallons per 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.
Operation of the city’s water system involves intricate relationships between water rights, water
quality, State laws, water rights decrees, water delivery contracts, water-related agreements with
third parties, streamflows, reservoir storage operations, transmission pipeline operations, treatment
capacity, hydropower production, and water demands.
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 tributaries of the Colorado River.
Past and current studies predict that as long as current supply and drought management strategies
remain in place, the city will have enough water in the future, even with climate change and predicted
population increases. Therefore, the focus of the SWMP is not, “Where does the city find more
water?” The focus is rather on the future steps and considerations needed to manage the existing
source water system, including its aging infrastructure.
1.2 | Source Water Master Plan Contents
The SWMP contains two volumes. The first volume provides a summary level of detail aimed at a
general audience. Volume 1 is consistent with other city master plans and planning documents in terms
of format, content and level of detail. The second volume contained herein provides much more detail
on background, system management, issues and recommendations. Volume 2 provides the details
necessary for future execution of programs and projects. Volume 2 also documents critical system
information in one place in a way that has never been done before, which will be valuable to current
and future staff. The second volume is prepared more for an audience having or desiring detailed
institutional knowledge of the source water system.
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Final - April 2009 Page 1-2
Volume 2 contains seven chapters as well as appendices. A brief introduction to the SWMP is
provided in Chapter 1, and Chapter 2 defines the purpose and scope. Chapter 3 describes the
management of the source water system. Background and description of source water assets is
provided in Chapter 4, and Chapter 5 provides information on water availability, water use and
water quality. Chapter 6 describes issues to be addressed over the next 20 years and beyond, and
Chapter 7 contains specific recommendations to address many of the issues described in Chapter 6.
The appendices are in electronic format attached to Volume 2 on a DVD.
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Final - April 2009 Page 2-1
Chapter 2
2 | PURPOSE AND SCOPE
2.1 | Purpose of the Source Water Master Plan
The SWMP is intended to be a foundation document that will allow informed decision-making
regarding one of the city of Boulder’s most important assets, 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 1800s 1 . 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. The SWMP documents the current status of the city’s water resources and raw
water facilities and defines issues needing to be addressed to provide for the city’s future water
supply needs.
2.2 | Previous Raw Water Master Plan
The city’s previous Raw Water Master Plan (RWMP) was completed in 1988 2 . In 1987, the city
initiated a public process to evaluate the water supplies that Boulder owned and discuss options for
use of the water. The studies resulted in the 1988 RWMP, which focused more on water yield and
water use in the city and less on raw water system infrastructure. Following presentation of the
RWMP, City Council adopted specific policies regarding instream flows, meeting water system
reliability and water quality goals, water conservation, and disposition of Windy Gap water and
replacement with other water sources. Many of the recommendations in the RWMP have been
implemented over the past nineteen years. In addition, some changes that affect water supply have
occurred and new information is now available. Therefore, it is a suitable time to review one of the
key findings of the previous master planning effort, which was that the city owned sufficient water
supplies to meet its build-out water needs. Although changes since that time may have affected water
supplies, it appears still to be a valid determination. Examples of these changes are:
Establishment of reliability criteria for the water system
Both in 1988 and the present, the determination that the city’s water supplies are believed to be
adequate does not mean that there will never be reductions in deliveries to water customers in
times of moderate to severe drought. City Council adopted reliability goals in 1989 based on
reliability criteria that define the extent to which water should be provided for various uses
during droughts. Assuming future hydrology is similar to the past, current modeling shows that
Boulder’s existing water supplies should be able to meet the reliability criteria and provide
sufficient water to meet all municipal water needs in nineteen out of twenty years under build-out
demand conditions. However, this conclusion should and will be revisited as new information
becomes available about the effects of climate change or as other changes take place that affect
Boulder’s raw water supplies and system. By setting reliability criteria for the city’s water system,
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Final - April 2009 Page 2-2
Boulder has taken a step toward responsible water planning that has yet to be taken by many
other Colorado municipalities. See section 5.1.1.4 for a description of the reliability criteria.
Increased preparedness for drought
In 2003, the city prepared a Drought Plan that defined several drought stages and the steps to
be taken in response to a drought declaration to assure that the water system could meet the
adopted reliability criteria 3 . For the five years in every hundred that water use can be reduced
and still comply with the reliability criteria, water system modeling incorporating the drought
responses contained in the Drought Plan shows that voluntary use reductions should be sufficient to
address the drought shortages in three to four of those five years.
Sale of Windy Gap Project water
Although City Council did not recommend a permanent reduction in the yield of the city’s water
portfolio through sale of water in 1988, they did recognize that the Windy Gap water was the
city’s most expensive and least reliable water. City Council recommended that staff attempt to
reconfigure the city’s water portfolio through sale of Windy Gap water and replacement of the
Windy Gap 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 County, and to purchase the
Barker System (Boulder Canyon Hydroelectric Project) from Public Service Company of Colorado
(PSCo, now Xcel Energy).
Improved water system modeling
The city has a far greater understanding of the source water supply system water yields and
interactions with other water systems due to the development of a detailed model of the city’s
water system over the past two decades. This model has been refined and updated during that
period and is now capable of providing sophisticated operational modeling of the city’s water
system and yields under many hydrologic conditions.
Year-round operation of Boulder Reservoir Water Treatment Facility
The Boulder Reservoir Water Treatment Facility began operating year-round in the mid 1990’s.
Prior to that time, it had been operated as a summer peaking plant. The change was due to
higher water demands from Boulder’s growing population and to support maintenance of a
drought reserve in the city’s upper Boulder Creek reservoirs.
Better management of water supplies to protect drought reserves
During the 1980’s, the city had been taking as much water as possible out of the sources that
feed Betasso Water Treatment Facility each year, possibly jeopardizing the city’s ability to
sustain water deliveries in drier years. Based on recommendations in the 1988 RWMP, the city
began maintaining a storage reserve pool in upper Boulder Creek reservoirs to assure that there
would be sufficient water supplies available to operate Betasso during drought periods. There
are two elements to the storage reserve pool: carry-over water and emergency drought reserves.
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Final - April 2009 Page 2-3
Rather than drain reservoirs every year, the city carries water over from wetter years for use
during drier years when there is insufficient streamflow available to fill the upper reservoirs.
Carry-over goals are 3,000 acre-feet per year in Barker Reservoir and 1,000 acre-feet per
year in the Silver Lake watershed. The city maintains an emergency drought reserve pool to
provide for a year’s worth of essential indoor needs during a severe, unplanned for drought. The
city’s emergency drought reserve pool is 3,000 acre-feet in the upper reservoirs (Barker and
Silver Lake watershed reservoirs) and 800 acre-feet in Boulder Reservoir. In order to provide for
carry-over water and maintain emergency drought reserve pools, a larger percentage of
municipal water must be delivered through the Boulder Reservoir Treatment Facility than had
been prior to the RWMP.
More upper basin storage with purchase of Barker Reservoir
In 2001, the city purchased the Boulder Canyon Hydroelectric Project, including Barker Reservoir,
from Xcel Energy. Although the city had agreements dating back to the 1950’s allowing the city
to use a portion of the facilities for municipal water supply purposes, the purchase increased
Boulder’s reservoir storage space by 3,686 acre-feet.
Establishment of a Water Conservation Program and Office
Based on recommendations in the 1988 RWMP and 1990 Treated Water Master Plan 4 in 1990
City Council approved implementation of an enhanced water conservation program with the
primary purpose of deferring the expansion of the Boulder Reservoir Water Treatment Facility.
The new Water Conservation Program and Office was established in May 1992 to direct the
efforts of reducing overall water consumption within the city and specifically to reduce summer
peak demand usage. The Water Conservation Program was designed to promote water
conservation through voluntary measures that create a greater public awareness of the resource
and encourage wise water use.
Water Conservation Futures Study
The 2000 Water Conservation Futures Study developed baseline water demands for the city’s
urban service area for the year 1995 based on monthly metered end use data. Various
adjustments were made to accommodate factors such as annual weather variations and
unaccounted-for water. Total demand and demand by various end use categories was projected
from the base year of 1995 through 2020. The study also developed demand projections for a
number of water conservation scenarios of varying degrees of intensity. Ultimately, the City
Council selected the Comprehensive Conservation Scenario that was designed to address both
indoor and outdoor water use patterns. This scenario was intended to result in a 10% reduction in
water use at build-out (approximately 2025) when compared to the water conservation program
in place in 2000, and about a 25% reduction in water use when compared to no conservation
program being in place.
Commitment to instream flow program
Based on recommendations in the 1988 RWMP, the city entered into an agreement with the
Colorado Water Conservation Board (CWCB) in 1990. Since the CWCB is the only entity that can
use water for the specific purpose of providing instream flow, the city donated use of municipal
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water to the CWCB for instream flow maintenance in North Boulder and main Boulder creeks. This
water can be pulled back for municipal use in times of drought or emergency.
Concerns about climate change
Climate science has expanded enormously over the past decade. Climate change models that
once could only roughly approximate possible global-level changes are now providing plausible
information at a more local scale. The city recently completed a cutting-edge study that
determined a likely range of future increases or decreases in the city’s water supplies due to
climate change. The study used data generated by a range of climate models for Boulder’s
watersheds to produce simulated streamflow sequences. This information was then fed into the
city’s water system model to determine any effects on Boulder’s water rights and water yields.
Growing awareness of the risks and effects of wildland fire
Wildland fire poses a threat to the city’s water supply in part because of the severe erosion that
can result after an intensely hot fire. If sediment and debris were to accumulate in the city’s
reservoirs following a wildland fire, the city would experience serious treatment challenges, taste
and odor issues, and a potential reduction in the city’s usable water supplies. Recent examples of
the effects of wildland fire on water supplies in Colorado, such as the effects on Cheesman
Reservoir following the Hayman fire in 2002, have increased the city’s awareness of protecting its
supplies against such risks 5 .
2.3 | Scope of the Source Water Master Plan
The City of Boulder was incorporated in 1871 and has over time developed a stable administrative
framework including policies that apply to management of the source water system. In 1989 City
Council adopted the RWMP, which provides policy direction on a number of items. The RWMP along
with numerous other city documents provide the policies that guide management and operation of the
source water system. The following list provides some of the key documents:
Raw Water Master Plan
Treated Water Master Plan
Drought Plan
Middle Boulder Creek Water Source Management Work Plan
Water Quality Strategic Plan
Water Conservation Futures Study
Source Water Impact Assessment
Boulder Valley Comprehensive Plan
Instream flow studies
Historic water system studies
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The SWMP does not change previously established policy or direction but rather includes
recommendations for minor adjustments and/or enhancements to the established policies. The SWMP
includes a policy discussion that builds upon the recommendations, policy directives and principles
from the RWMP and other documents that have guided water utility operations for over 20 years.
The SWMP is a general planning process and document. It supports sustainable management of the
city’s source waters in a manner that provides for the city’s needs through drought periods without
violating the adopted reliability criteria. The SWMP contains a comprehensive review of all available
information regarding the city’s water supplies as a basis for future planning efforts and decision-
making. The current belief that the city’s presently-owned water rights portfolio will be sufficient to
meet the city’s water needs at full build-out of the city service area will need to be re-visited on
occasion in the following decades to assure that it remains valid. The SWMP documents the factors
that are the basis for findings of adequate water supply so that future changes that might alter these
factors can more readily be identified. It also identifies new studies that may be needed and raw
water system facilities that need repair or construction.
The scope of the SWMP includes several different efforts, such as:
compiling existing information about the city’s source water, such as background information, a
review of the city’s raw water system assets, current operation and maintenance practices,
agreements, and other legal constraints on the city’s raw water operations;
documenting current policies for management of the city’s source water;
reviewing water use levels and water rights yields to assist in periodic re-evaluation of future
demands;
defining emerging issues that affect how the city will manage and operate its source water system
in the future;
recommending future studies and actions that should be undertaken;
providing general budgeting information and project prioritization to guide development of the
twenty-year Capital Improvements Program so that source water deliveries are dependable,
and;
recognizing and being compatible with other city master plans and strategic plans.
It is not intended that the SWMP will generate new data, complete new studies, or evaluate projects
at a level more appropriate for the city’s Community and Environmental Assessment Process (CEAP).
The SWMP provides guidance on which future actions should be developed further through more
specific efforts such as detailed studies, project implementation teams or a project-specific CEAP.
Although the SWMP discusses issues from other areas that are related to source water, such as water
conservation or water treatment, any recommendations on related issues are drawn from existing
master plans, strategic plans or other documents that have received City Council review.
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1 Fred A. Fair Engineering Association. (1919). Report to E.O. Heinrich, City Manager, on the water rights of the city of Boulder, Colo. in
comparison with the physical facts that affect them. Boulder, CO.
2 WBLA, Inc. (1988). City of Boulder Raw Water Master Plan. Boulder, CO.
3 City of Boulder, Aquacraft, Inc., & Hydrosphere Resource Consultants, Inc. (2003). City of Boulder drought plan volume 1: Drought
response plan. Boulder, CO; and City of Boulder, Aquacraft, Inc., & Hydrosphere Resource Consultants, Inc. (2004). City of Boulder
drought plan volume 2: Drought plan and technical information and analysis revised November 2004. Boulder, CO.
4 Brown and Caldwell Consultants. (1990). City of Boulder treated water master plan. Phase I. Denver, CO.
5 City of Boulder. (2003b). Wildland fire preparation plan for drinking water watersheds. Boulder, CO.
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Chapter 3
3 | MANAGEMENT OF BOULDER’S WATER SUPPLY
3.1 | Management of Boulder’s Raw Water System
The city of Boulder supplies municipal water to all of the developed area within the Boulder Valley
Comprehensive Plan boundaries. The city’s water utility provides safe and reliable drinking water by
diverting raw water from the city’s source water basins, treating the water at the city’s two water
treatment plants and distributing the water through distribution system pipelines.
An extensive system of raw water pipelines, reservoirs and facilities is operated and maintained to
assure adequate deliveries to the city’s water treatment plants at all times. The city operates eight
hydroelectric plants that generate power from the pressure that develops within the water supply
system as water is delivered from the mountains. The city also leases raw water supplies to
agricultural users and manages the instream flow program for Boulder Creek.
Raw water is diverted for either direct use or for storage in reservoirs for later use. In order for the
city to divert water, the city must have a water right that is in priority to take water at the time.
Boulder owns a large water rights portfolio that includes both junior and senior rights. All diversions
must take place in accordance with decrees and state water administration requirements and must be
documented.
The operation of the city’s water system involves intricate relationships between the city’s water rights,
water rights owned by others, water quality, state water laws, the city’s water rights decrees,
delivery contracts and other agreements, streamflows, reservoir storage operations, transmission
pipeline operations, treatment capacity, hydropower production and water demands. There are
many restrictions on what can be done with the city’s water supplies based on legal or contractual
constraints. Some of the city’s water supply facilities have capacity or operational limitations. The city
operates some of its raw water system based on long-standing practices and philosophies such as the
emphasis on protecting water quality at its source that dates back over a century. However,
Colorado’s semi-arid climate is the over-riding influence on the choices made by the city when
managing its water supplies.
Despite the limitations on management of Boulder’s water supplies, the city does have a greater
degree of flexibility than many other Colorado municipalities. The city’s water rights portfolio is
robust and should be sufficient to meet the city’s needs at its build-out under most future hydrologic
scenarios and up to the level of reliability specified by City Council.
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3.2 | Historical Factors Affecting Water Management
3.2.1 | HISTORY OF COLORADO WATER DEVELOPMENT
Prior to the settlement of the West, the law controlling water use was based on riparian rights that
had been defined through common law. “Riparian rights” meant a land owner adjacent to a stream
had a right equal to every other land owner who was adjacent to the stream to make a reasonable
use of the water upon his land, for his household needs, or for his livestock while leaving the stream
undiminished in quantity or quality 1 . This approach worked in wetter climates with abundant
streamflow but proved ineffective in the arid West where it was often necessary to transport water
away from streams to use on land under mining claims or land that was agriculturally viable. In the
absence of any governmental enforcement authority, early settlers adopted a practice of “first in
time, first in right” to settle water disputes. The first settlers to apply water to a beneficial use gained
a preferential right to access any available water in times of shortage without regard for the source
of water and the point of use. Therefore, a new law based on community custom that came to be
known as the prior appropriation doctrine supplanted riparian water allocation methods used in the
eastern states. 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 2 .
In 1861, at the first session of the Colorado Territorial Legislature, an act was passed that allowed a
land owner who was not adjacent to a stream to construct a ditch over land lying between his land
and the stream to gain access to irrigation water 3 . By 1864, 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. 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. As a last
resort, a water user could file a lawsuit with the court, but any decree issued was only binding on the
parties to the lawsuit and not to other water users 4 . This sometimes led to controversies during times
of shortage such as one that occurred during the dry summer of 1874 between the Union Colony at
Greeley and a new settlement located upstream at Fort Collins. Newly constructed ditches at Fort
Collins captured all of the water in the Poudre River leaving no water for diversion by the older
ditches at Greeley. A meeting of about forty irrigators was held and was described by David Boyd,
an attendee, as follows:
“…the Collins parties were told that if their policy of the ditches highest up stream
taking what they wanted was the one to be pursued, then we [Greeley irrigators]
could go above them, and there would result an interminable and exhaustive
race….Most of the Greeley delegates might have been made to yield but for the
defiant attitude of those up stream. At length patience seemed to…cease being a
virtue, and he hurled back defiance in hot and unseemly language….Force must
meet force….many of us had seen as rough service some ten years ago [in the
Civil War] as we were likely to experience in an encounter with these water
thieves….Every man to his tent, to his rifle and cartridges….It was finally agreed
that they would let us down some water….A promise they did not keep nor mean
to keep….A general rainstorm came in about a week afterwards and saved us;
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but from this day forth we had set our hearts on having some regulations looking
towards…the principle of priority of appropriation”5 .
Even after the prior appropriation doctrine was written into the Constitution of the newly-formed
State of Colorado in 1876, no government entity existed to enforce water rights priorities. In order to
address disputes such as on the Poudre, farmers called for an irrigation convention to be held in
Denver to discuss possible legislation regarding water diversions. In December 1878, the irrigation
convention was held and a committee was formed to draft legislation that was then presented to the
legislature in 1879. The proposed legislation provided for:
1. Creation of water districts corresponding to areas irrigable by natural streams;
2. Appointment of water commissioners with the authority to decide the relative
priorities of irrigation water rights based on the historic record;
3. A plan for creating a historic record;
4. Reservoir regulations;
5. Appointment of a state engineer, and;
6. Stream gauging.
The legislation was passed without the provisions for a state engineer or stream gauging. In the fall of
1879, the Poudre district was the first to appoint a referee to hear testimony to establish a historic
record of water use under the new law 6 .
The non-judicial approach was opposed by many because it would provide little or no opportunity
for due process through the courts for other water users who objected to decisions regarding priority
of rights made by the referee or the water commissioner. The referee’s report on the Poudre fueled
the controversy because it granted very large diversion rights to ditches of limited capacity based on
testimony of farmers with no engineering background in determining water flow or ditch capacities.
When an application was made to the district court based on the referee’s report, Judge Elliott hinted
that the 1879 law was unconstitutional. His ruling stated that the law was defective in its lack of
requirement to follow necessary rules for judicial procedure. The Colorado Supreme Court upheld the
ruling 7 .
Disputes between water users continued, including one that became the basis for a court case called
Coffin vs. 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 water through his
property during a dry period in 1879. Believing that ownership of riparian land should give a better
right to use of water than the right of the upstream Left Hand Ditch Company to carry water to land
away from the river, Mr. Coffin resorted to the self-help method of using dynamite on the Left Hand
Ditch headgate and diversion dam. After heated discussions among the parties that may have
involved threats of shotgun use, the parties calmed down sufficiently to take the case to the courts 8 .
The State Legislature, in an attempt to address the rulings on the Poudre case and to bring some
order to state water administration, passed the Adjudication Act of 1881 that firmly established use
of the prior appropriation doctrine in Colorado. The act required claims for a water right to be
submitted to the courts for recognition so that the State Engineer’s Office, created through the
legislation, could administer the rights according to priorities established by the courts 9 . Water rights
that may have been put to use at an earlier date than others but that did not receive court
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recognition could not be treated as senior by the water commissioners. The legitimacy of Colorado’s
use of the prior appropriation doctrine was ultimately confirmed in 1882 when the Colorado
Supreme Court issued a ruling in the case of Coffin vs. Left Hand Ditch stating that prior
appropriation was the only law recognized for water allocation in Colorado and no riparian rights
existed 10 .
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 of the date of their first application of
water to beneficial use in order to gain a place in line with an administrable priority date. Water
rights 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
Boulder County District 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 would not be
recognized until later. Ninety-eight irrigation ditches in the Boulder Creek basin were adjudicated in
1882 and prioritized by their appropriation dates. Later general adjudications incorporated
reservoir rights and rights for municipal and industrial users.
This system has evolved into the system we have today where filings for new appropriations of water
or changes to existing water rights are filed at any time in Water Court without need for a general
adjudication. State law was substantially revised in 1969 to streamline legal procedures for dealing
with water rights and to create a special Water Court for each of seven Water Divisions
corresponding to the major river basins in the state 11 . Applications to the Water Court are published
monthly in a Water Resume. Anyone with concerns about the application then has sixty days to file an
objection. Simple or non-controversial cases can be heard in front of a Water Referee to allow
review of the proposed beneficial use and to assure no detrimental effects (known as “injury”) are
caused to other water rights. More complicated or contested cases can be transferred to the Water
Judge. The issues in most cases are settled between applicants and objectors with a stipulated decree
sent to the Water Court for judicial approval. In a few cases, settlement cannot be reached, so a trial
must be held before the Water Judge. If a Water Court ruling is appealed, it goes directly to the
Colorado Supreme Court.
3.2.2 | DEVELOPMENT OF CITY WATER SUPPLIES
3.2.2.1 | TOWN OF BOULDER BEGINNINGS
The first settlers arrived in the Boulder Valley shortly after gold was discovered in 1859. The first
irrigation ditches that diverted from Boulder Creek were dug that same year. By 1870, so many
irrigation ditches were in operation in the Boulder Creek basin that ditch companies with more junior
water rights were called out of priority in late summer when there was only enough water in the river
for the senior diverters 12 . Ditch companies began building reservoirs to store water during the high
spring runoff period to assure water supplies in late summer.
The Town of Boulder incorporated in 1871. At that time, town residents either carried water to their
houses in buckets dipped into Boulder Creek, dug small alluvial wells, or obtained water from
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irrigation ditches for domestic water needs. Small laterals running from ditches such as the Farmers
Ditch and Anderson Ditch ran along most of the east-west streets and carried water to individual
houses for shareholders in the company 13 .
A private water company, the Boulder Aqueduct Company, was formed in May 1872 by Andrew
Macky, Alfred Brookfield, and James P. Maxwell for purposes of delivering water to Boulder homes
through pipes. The Town Board of Trustees gave the company permission to lay wooden pipes in city
streets in 1873. However, some citizens believed that provision of water for Boulder should be
publicly controlled 14 .
On July 14, 1874, the town’s citizens filed a petition with the Town Board of Trustees requesting that
a vote be held to issue bonds for a municipal water system, in part because Boulder’s citizens were
already concerned with water quantity, quality and reliability of water supplies. There was also
concern about the possibility of a fire burning through the town without a pressurized water system
capable of delivering large amounts of water quickly. In response to these concerns, the town began
operating a municipal water system in 1875. The Town of Boulder Reservoir, the town’s first storage
reservoir, was constructed in 1875 north of the mouth of Boulder Canyon at Red Rocks above the
headgate of the Farmers Ditch. The reservoir filled by the newly-constructed Town of Boulder Ditch
running from Boulder Creek. Water ran from the reservoir in an eight-inch cast iron pipe down to the
intersection of 12th Street (Broadway) and Pearl Street. Many residents collected their domestic water
in buckets from public spigots at what is now the old courthouse site.
The ditch that filled the reservoir, named the Town of Boulder Ditch, was granted a decree in the first
general adjudication of water rights on Boulder Creek in June 1882 and was given an 1875
appropriation date specifically allowing domestic use. It is unusual that the domestic use of water
diverted under the Town of Boulder Ditch right is mentioned in this decree since the Colorado
Legislature did not specifically provide for adjudication of domestic or other uses until 1903. Prior to
this, domestic water uses were generally considered to have very little consumption and to be
incidental to associated agricultural uses 15 . The need for decrees for storage rights was not
recognized on Boulder Creek until 1907 since, prior to that time, sufficient water supplies were
usually available to fill existing reservoirs at times of the year when direct flow rights were not
claiming the entire flow of the creek.
By 1879, Boulder had already begun to have difficulty extending its water system piping fast
enough to fulfill the grand visions that some residents had for the young town, which by 1882 would
be re-incorporated as the City of Boulder. One of these residents, J.P. Maxwell, owned a great deal
of land on Mapleton Hill that he wished to develop into up-scale housing. Maxwell was very familiar
with the city water system, having surveyed the route to be taken by the Town of Boulder Ditch and
serving as the State Water Commissioner for Boulder Creek. However, he was unable to convince the
City Council to expand the municipal water system to serve Mapleton Hill. As a result, Maxwell and
his partner, George Oliver, formed the for-profit Silver Lake Ditch and Reservoir Company (Silver
Lake Ditch Company) in 1887 to serve their housing developments 16 . They built dams on two natural
lakes to create two reservoirs, Silver Lake and Island Lake, near the headwaters of North Boulder
Creek just below the Continental Divide. The Silver Lake Ditch Company, formed in 1888, delivered
the Silver Lake water into the Silver Lake Ditch, which has a headgate near the mouth of Boulder
Canyon and runs north along the western edge of Boulder. J.P. Maxwell later bought out his partner
and became the sole owner of the Silver Lake Ditch Company 17 . His company delivered water to
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individuals who were beyond the service boundaries of Boulder’s municipal water system and who
entered into water delivery contracts with the Silver Lake Ditch Company.
3.2.2.2 | WATER QUALITY AND THE FIRST CHANGE OF LOCATION OF BOULDER’S
INTAKE
Beginning in the early 1880s, Boulder residents complained about cloudy water in the municipal
water system that had been polluted by mining in the mountains above and west of Boulder and from
discharges into the stream from settlements in the canyon 18 . The problem became so bad that the City
Council appointed a committee in 1890 to investigate the means to supply Boulder with clean,
reliable water. The committee recommended moving the city’s water intake from the existing point on
Boulder Creek at the mouth of Boulder Canyon to a point further upstream 19 . Therefore, in 1890, the
city constructed a new upstream intake called the “Blanchard intake i “ or the “lower intake” on a site
known as the Horseshoe Placer mining claim ii , which was located on Boulder Creek about one mile
upstream of the confluence with Four Mile Creek 20 . A pipeline was constructed from the new
Blanchard intake to the new Sunshine Reservoir. This reservoir was located on the second land
purchase from John Brierley at the base of Sunshine Canyon on the Gallup Ranch and was 100 feet
in elevation above the old Town Reservoir 21 . Citizens hoped that with these changes, water quality
would improve. However, as more and more tungsten mills began operating upstream of the new
intake, water quality problems once again became apparent 22 .
3.2.2.3 | DEVELOPMENT OF THE SILVER LAKE WATERSHED
Relocating the pipeline intake upstream of Boulder Creek’s confluence with Four Mile Creek reduced
watershed area contributing to the municipal water supply. This became a problem during the dry
winter of 1901-1902 when Boulder experienced its first serious shortage of water. Water stored in
Silver Lake was released on an emergency basis to supply the town. As a result, in September 1902,
the Council voted to visit Silver Lake and explore the idea of obtaining a high-elevation reservoir for
the town. Also in 1902, the City Council discussed the water quality problems caused by having the
water system intake located at the lower elevations of Boulder Canyon and began discussing the
possibility of again moving Boulder’s water intake upstream 23 .
In 1903, J.P. Maxwell made a proposal to the City Council for a public-private partnership to build a
new municipal water system with high-elevation reservoirs feeding pure water into a pipeline running
from a point outside Nederland all the way to Boulder 24 . Maxwell and his son owned land in the
area of the proposed reservoirs. The City Council was interested due to the prospect of a clean water
supply, but was concerned about the expense of the project. After much public debate, the idea of a
public-private partnership was disallowed by a court decision 25 .
Maxwell had been involved in the development of city water supplies since the beginning and was
determined to see the city proceed with improvements to the municipal water system. However, the
motives behind his advice to City Council were questioned since he was City Engineer at the time and
i So named after the owner of the nearby Blanchard Inn.
ii Although there are multiple documents that support the fact that the city did indeed construct and use the Blanchard intake at this site
in 1890, it appears that the city did not purchase the land for the Horseshoe Placer until 1904 and 1952. City Council minutes from
June 20, 1890 describe the location of the site as located “westerly and southerly up Boulder Canon, along Boulder Creek, past the
mouth of Four Mile to what is called the Gallup Ranch, about one mile south westerly from said mouth of Four Mile, and over and across
said ranch… that said…improvement terminating on said ranch.”
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also owned the land being offered for sale to the city. After several false starts, the Council asserted
its desire to control the destiny of the young city and developed a plan to acquire ownership of a
high-mountain watershed and water rights and to pipe the pure water, free from the pollution caused
by the mines and settlements, to Boulder 26 .
The city finalized its first purchases of land in what was to become the city-owned Silver Lake
Watershed in 1904 when it acquired lands on North Boulder Creek below Arapaho Glacier from
Clint Maxwell, son of J.P. Maxwell 27 . The purchased land contained the Triple Lakes, which were
natural lakes, and Oval Lake, which had been raised with a small dam built by Clint Maxwell. A
larger dam was later installed by the city at Oval Lake from 1906 to 1908 to create a larger
reservoir named Goose Lake 28 .
In 1906, the city purchased Albion Lake and surrounding area for $12,000 from J.P. Maxwell 29 and
Silver and Island Lakes for $34,000 from the Silver Lake Ditch Company 30 , which by then had J.P.
Maxwell as its sole owner. Maxwell secured an agreement between the company and the city that
obligated the city to continue deliveries of storage water from space reserved in the newly-
purchased city reservoirs to the company so that the company could then deliver water through the
Silver Lake Ditch to holders of water delivery contracts. The agreement provided that the city’s
obligation would decline over time as contract holders abandoned their Silver Lake Ditch rights or
were “supplied by other sources,” such as by annexation into the city 31 . Maxwell then sold the
remaining interests of the Silver Lake Ditch Company in 1907. The new owner of the company, W.W.
Degge, owned land north of Boulder below the ditch and had dreams of creating a suburban
paradise. Degge, through his new company, assumed the obligation to deliver water to holders of the
company’s water delivery contracts 32 .
With a plan for high-elevation reservoirs proceeding, the city began construction in 1906 of the
Boulder City Pipeline running from the Blanchard Intake at Orodell up to a tiny mining camp called
Lakewood just north of Nederland. A diversion from North Boulder Creek was built at the site along
with Lakewood Reservoir, which acted as a forebay for the new pipeline. The site was downstream of
Boulder County Ranch (now called Caribou Ranch) where the Primos Tungsten Mill was located. Como
Creek was re-channeled to prevent its polluted waters from mixing with the purer water of North
Boulder Creek as it flowed into Lakewood Reservoir 33 .
The city acquired twenty acres of land where Lakewood Reservoir is now situated in 1906 from T.N.
Barnsdall of Pittsburg, Pennsylvania 34 . In addition, the city acquired easements for the Boulder City
Pipeline (a portion of which is now called the Lakewood Pipeline) and for diversions from North
Boulder Creek and from Como Creek across lands owned by Mr. Barnsdall. Mr. Barnsdall was given
the right to construct a pipeline from North Boulder Creek that would drive a hydroelectric plant
before discharging into Lakewood Reservoir. City officials were considering the potential need to
extend the Boulder City Pipeline further up into the Silver Lake Watershed since the city also
acquired the right to connect a future pipeline from Silver Lake Reservoir into Barnsdall’s pipeline
“should future emergencies require, whether from pollution of the stream or otherwise”35 . However,
Mr. Barnsdall never constructed his pipeline and power plant, so the city never constructed a
connecting pipeline.
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3.2.2.4 | BOULDER DISTRICT COURT’S 1907 GENERAL WATER RIGHTS ADJUDICATION
In January 1907, the Boulder District Court issued notice of a general water rights adjudication
proceeding. The court issued a decree in March 1907 that recognized all water rights that had been
developed since the 1882 general adjudication and all rights that had missed the previous general
adjudication, and recognized reservoir storage rights for the first time 36 . Prior to this, reservoir
owners had just taken water from the stream whenever direct flow rights were satisfied or not calling,
but enough reservoirs had been built that priorities to the remaining water needed to be established.
In this adjudication, the city was decreed a 20 cubic feet per second (cfs) water right for the Boulder
City Pipeline that allowed direct flow use of water diverted from North Boulder and Como Creeks for
municipal purposes with an appropriation date of 1904.
The court also issued the first decreed water rights for Silver Lake, with appropriation dates of 1887
and 1906; Island Lake, with appropriation dates of 1890 and 1906; and Goose Lake with
appropriation dates of 1901 and 1906 and a conditional water right for enlargement. The decree
recognizes the city’s right to use the water under each priority for municipal purposes, including “the
exhaustion” of the 1887 Silver Lake and 1890 Island Lake rights that were granted priority dates in
the decree based on the original use for irrigation by the Silver Lake Ditch Company 37 . The city has
interpreted “the exhaustion” of use for municipal purposes of water diverted under each of the
specified decrees as allowing for one time municipal use of all of the water, and the city has not
historically reused the water after its first municipal use.
3.2.2.5 | BOULDER CANYON HYDROELECTRIC PROJECT
The population in Denver and Boulder doubled between 1890 and 1905 and demand was great for
new technology using electricity. In 1906, Myron T. Herrick formed the Central Colorado Power
Company to create an extensive network of hydroelectric power plants and transmission lines
throughout the Rocky Mountains. In 1909, Eastern Colorado Power Company had combined assets
with Central Colorado Power Company and began planning for a hydroelectric dam on Middle
Boulder Creek. Construction of the Boulder Canyon Hydroelectric Project power plant was
accomplished by sending construction materials by train to Orodell. The materials were off-loaded
onto specially constructed wagons that followed a track to the plant site 38 . Teams of up to 16 horses
were used to pull the wagons 39 . Workers’ quarters, stables, a blacksmith shop and a mess hall were
constructed near the site, creating a small village for several years during the construction 40 .
A tramway was constructed along the route of the penstock to carry materials up the steep mountain
side to Kossler Reservoir 41 . Kossler Reservoir was named for the landowner, one of Boulder County’s
historic families that owned land in the Flagstaff Mountain and Walker Ranch areas. The penstock’s
1828-foot drop between Kossler and the hydroelectric plant created the highest head of any plant in
the United States at the time. Upon completion of the penstock, it was found that the riveted butt joints
in the steel penstock could not withstand the 800 pounds per square inch water pressure that
developed in the pipeline, and it leaked significantly. Using the then-new acetylene welding process,
construction workers discovered that hammering the weld while it was still warm prevented the joints
from cracking as they cooled. Discovery of this so-called ball-peen welding method is an engineering
innovation credited to the project 42 .
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Barker Dam was completed in August 1910, 18 months after construction began. The dam and
reservoir were named for landowner Hannah Barker, who had refused to sell her ranch holdings to
the Central Colorado Power Company, necessitating condemnation proceedings to acquire the dam
and reservoir site 43 . The hydro plant went into operation on August 4, 1910.
3.2.2.6 | ADDITIONAL SILVER LAKE WATERSHED ACQUISITIONS
Most of the land in the Silver Lake Watershed was purchased by the city from the federal
government for $1.25 per acre based on three grants made by the US Congress in 1907, 1919, and
1927. Grants of the right to purchase the land were specifically based on the city’s need for a water
supply. On March 2, 1907, the U.S. Congress made its first grant of land in the Silver Lake
Watershed to the city of Boulder. The act 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”44 . The Congressional Record for the 1907 bill
conveying land to Boulder states, “The object and purpose of this bill are 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 city of Boulder...”45 .
That same day, Medicine Bow National Forest was expanded by Presidential proclamation to include
lands in Colorado, including some of the lands adjacent to the Silver Lake Watershed 46 .
In November 1907, the city purchased land near the old Albion mining camp on the north fork of
North Boulder Creek near Silver Lake from The Cashier Mining and Milling Company with the
agreement that The Cashier Mining and Milling Company could capture any water seeping out of
Albion Lake to run through a pipeline that he planned to construct to generate hydropower for mining
operations 47 . Thomas Wood, manager of The Cashier Mining and Milling Company operation at
Albion, filed notice with Boulder County in 1905 of intent to build the Cascade Pipeline. The pipeline
was built by 1908 to drive a hydroelectric plant located below Albion Lake 48 .
Following the city’s acquisition of Albion Lake, the City Engineer, Fred Fair, was authorized by City
Council to build a dam at the site in 1911. A contractor was hired and work took place in 1912 and
continued until the city ran out of money. Although the dam was originally designed to be sixty-feet
high, it was only built to a height of 39 feet and no new work occurred after 1913 49 . The City
Council also authorized the construction of a new dam at Silver Lake in 1911. Soon after work started
in April 1912, it was halted by the State Engineer. The contractor, who was the low bidder, claimed
the delay would substantially increase costs. He did not complete the specified work and the contract
was cancelled in 1913 50 .
By 1919, it was concluded that a pipeline intake was needed at an elevation even higher than
Lakewood Reservoir to avoid contamination of the water supply with mine runoff from the Primos
Mill 51 . The Boulder City Pipeline was extended to a point within the boundaries of the Silver Lake
Watershed, resulting in two segments that would later be called the Lakewood Pipeline and the Silver
Lake Pipeline. The intake to the Silver Lake Pipeline was identified in the city’s water rights decrees
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. When Boulder developed the plan to extend the Boulder City
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Pipeline, the new pipeline intake was to be about 4 miles downstream of Silver Lake and of any
property owned by the city. The town wanted to protect the quality of water released from Silver
Lake as it flowed in the creek prior to diversion into the new pipeline. Boulder again approached
Congress and received a new grant in 1919 To Whom It May Concern: purchase more land in what is
now the lower part of the Silver Lake Watershed 52 .
Boulder sought to protect its new water supply from upper North Boulder Creek to prevent the water
quality problems that had been experienced in the past. In 1914, the city hired its first watershed
caretaker, in part to keep an eye on recreational users of the area to assure no polluting activities
took place. In about 1920, following a typhoid outbreak and amid fear of cholera, the town closed
all of its Silver Lake Watershed land to public access and authorized the watershed caretaker to
ticket trespassers 53 . The Silver Lake Watershed remains closed to public access not only to protect
water quality, but also to protect the fragile alpine environment, wildlife habitat and sensitive
university research studies of alpine and climate conditions that began in the 1930s.
In the 1920’s, a proposal to build a toll road that would bring commerce and tourists near Arapaho
Peak and the Arapaho Glacier was met with dismay by the city. The proposal was followed with a
recommendation by the United States Park Service that the Rocky Mountain National Park boundaries
be extended southward to include the Arapaho Glacier 54 . A final Congressional grant was obtained
in 1927 over the strenuous objection of the Park Service. Both the 1919 and 1927 grants 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”55 .
Over the years, Boulder has purchased additional parcels of land in the Silver Lake Watershed area
from private owners. The city now owns approximately 6,500 acres in the Silver Lake Watershed
containing thirteen reservoirs and natural lakes. Almost all of the water supply from the area comes
from the melting of the each winter’s snowfall. A fraction of a percent of the supply comes from the
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.
3.2.2.7 | CHANGES OF DITCH COMPANY SHARES TO MUNICIPAL USE
Boulder continued to grow and needed additional water rights of sufficient seniority to allow
diversions in late summer. By 1925, the city had acquired 14 ¾ shares in the Anderson Ditch
Company and 8 shares in the Farmers Ditch Company. These shares gave interests in the companies’
water rights that were only decreed for direct irrigation use on land below the ditches. Much of this
land had been annexed into the city and developed into houses and businesses served by the city’s
municipal water system. The city completed its first change of water right court proceeding in 1925 to
allow diversion of the city’s interest in the ditch companies’ water rights at the city pipeline intakes on
North Boulder Creek and to allow use of the water for municipal purposes 56 . Change of use court
decrees for additional Anderson and Farmers shares acquired by the city were obtained in 1942,
1963 and 1989. The diversion point for the Town of Boulder Ditch direct flow right was moved
upstream to Boulder City Pipeline headgates in a 1942 change of use case 57 .
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3.2.2.8 | FIRST RECONSTRUCTION OF BOULDER CITY PIPELINE
In 1939, the city began to rebuild the Boulder City Pipeline. The lower portion of the Boulder City
Pipeline below Lakewood Reservoir was originally constructed with cast-iron pipe with lead joints.
Segments of old pipe were replaced with steel pipe through World War II. The salvaged cast-iron
pipe was used to replace the clay tile pipe that had been used in 1919 to construct the upper portion
of the Boulder City Pipeline, which would become known as the Silver Lake Pipeline. After the city
began the pipeline reconstruction, the US Forest Service (USFS) issued a Special Use Permit for the
first time in 1939 for portions of the lower pipeline (about 30 percent) that crossed USFS land 58 . This
permit was a land use authorization in addition to the right-of-way that the city had occupied since
1906 based on the Act of July 26, 1866 59 and the Acts conveying land in the Silver Lake Watershed
to the city, which had been passed by the US Congress 60 .
During and after the war, steel was scarce, so thinner-walled pipe was used for rebuilding the lower
portion of the pipeline, which would become known as Lakewood Pipeline. The use of thin steel pipe
for Lakewood Pipeline meant that the pipe could not be fully pressurized with the entire head of
pressure that developed as water flowed from Lakewood Reservoir into the city. Therefore, air
evacuation valves and surge chambers were built at points along the pipeline to let air into and out
of the pipeline as water flowed up and down mountains and valleys to avoid the formation of
vacuum pressure that would collapse the pipeline. This mode of pipeline flow allowed an enormous
amount of air to become entrained in the water, which would eventually cause problems with water
treatment processes once Betasso Water Treatment Facility (WTF) was built 61 . Lakewood Pipeline
was not fully reconstructed until the 1950s.
3.2.2.9 | FORMATION OF THE NORTHERN COLORADO WATER CONSERVANCY
DISTRICT
During the 1930s, a severe drought hit most of the mid-section of the United States and resulted in
the Great Dust Bowl years. Water users in north-eastern Colorado experienced severe water
shortages. In 1937, they lobbied the state legislature to allow creation of conservancy districts so that
they would have the means to finance large water projects. The passage of the Conservancy District
Act of Colorado in 1937 provided for conservancy districts to be created and allowed for imposition
of up to a one mill general ad valorem tax as a revenue source from the general population of a
district rather than directly from water users alone 62 .
The Northern Colorado Water Conservancy District (NCWCD) was formed in 1937 for the purpose
of delivering West Slope water through the Colorado-Big Thompson (CBT) Project to water users in
northeastern Colorado as a supplemental supply to native basin water supplies. The CBT Project was
built by the United States Bureau of Reclamation and began operation in 1957. NCWCD agreed to
repay the federal government for that portion of the cost of the CBT Project attributable to irrigation,
municipal and industrial water supply. The federal government bears all costs related to the
hydropower production aspects of the project.
In 1937, it was thought that the construction cost for the CBT Project would be $44 million. Power
generation revenues were expected to provide about $19 million toward the cost. It was projected
that the project would provide an average annual water delivery to north-eastern Colorado of
310,000 acre-feet at a cost of $80 per acre-foot which could be paid back over forty years with no
interest at $2 per acre-foot 63 . In 1938, NCWCD signed a contract to repay a portion of the
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expected construction cost, “not to exceed twenty-five million dollars” over a period of forty years
beginning when the project construction was completed. NCWCD was required by the United States
to levy the one mil ad valorem tax allowed under state law and to charge water users no less than
$1.50 per acre-foot of water once the project was complete. The contract specifically listed project
features planned for the part of the CBT system north of, and including, Carter Lake, but described
the southern components of the system only as “conduits from the St. Vrain to Boulder Creek and to
South Platte River (now being studied)”64 . The southern components of the CBT delivery system
became an addition to the project that was paid for separately from the base contract 65 .
The first water was delivered from Grand Lake to the East Slope through the Adams Tunnel on June
23, 1947. Water was first stored in Carter Lake in February of 1954. The CBT Project became fully
functional with its first full year of water deliveries in 1957 66 . The city of Boulder and 30,000 acres
of adjacent land became part of NCWCD in 1953.
3.2.2.10 | DEVELOPMENT OF NEW WATER SUPPLIES FOR BOULDER – 1950’S
In 1949, city officials began to realize that the city would soon be facing water shortages due to the
extraordinary growth experienced following the end of World War II. Plans began to be developed
for expanding the city’s water supply 67 . By 1952, the city was concluding that joining the NCWCD
and obtaining CBT water was a preferred solution for resolving impending water shortages 68 .
Pressure to develop additional water supplies increased in the mid-1950’s when a severe drought
further strained the limits of Boulder’s Silver Lake Watershed and North Boulder Creek water supply.
The city’s supplies at the time consisted of transferred Farmers and Anderson Ditch rights, its relatively
junior direct flow decrees, and storage in the Silver Lake Watershed. The city’s direct flow rights
were routinely called out by downstream users with more senior rights, and the city was forced to
bypass direct flows and use mainly releases from storage reservoirs. During the severe drought year
of 1954, streamflows fell to below 50 percent of normal, and the city ran short of water.
In response to the crisis, Water Superintendent E.B. Debler proposed that the city obtain water
through exchange from the Public Service Company of Colorado (PSCo, now Xcel Energy), which was
by then the owner of the Barker system, and the City of Denver. Under this plan, the city diverted
water out of priority at its upstream diversions and replaced it at downstream locations with water
leased from PSCo and Denver. The city would later file for a decreed exchange right on Boulder
Creek based on these first water exchanges in 1954 69 .
The city also made plans to develop additional water supplies, which resulted in two additional water
sources in use by the city today – Barker Reservoir and Boulder Reservoir. The city entered into the
first of a series of agreements with PSCo in 1955 allowing Boulder to have limited use of the Barker
facilities 70 . In 1959, a new agreement was signed with PSCo that gave the city the right to store
4,000 acre-feet of water in Barker Reservoir 71 . Under successive agreements, the storage space
allotted to the city gradually increased until 1978 when it reached 8,000 acre-feet out of the
11,686 acre-feet of space in Barker Reservoir 72 . PSCo continued to use the remaining storage space
for water to generate electricity at the Boulder Canyon Hydro Plant.
Boulder Reservoir was completed in 1955 as a part of the 1953 agreement that allowed the city to
join NCWCD. The city had not joined NCWCD in 1937 at the time when the feasibility of water
delivery facilities to the southern part of the CBT system was still under study. Therefore, conditions
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for the city to join NCWCD were negotiated individually and included payment of the NCWCD ad
valorem tax back to 1937 and construction of a new reservoir northeast of Boulder in which NCWCD
could buy storage space. NCWCD agreed to pay one-third of the city’s construction cost for the “Twin
Lakes” Reservoir, later known as Boulder Reservoir, over a period of forty years 73 . The original
city/NCWCD agreement allocated one-third of the reservoir storage space to NCWCD, but this
amount was modified in later agreements to change seasonally 74 . The city was given a preferential
right to use of 90 cfs of capacity in the outlet canal from Boulder Reservoir to Boulder Creek for
delivery of the city’s CBT water to be exchanged for additional water taken at the city’s upper
Boulder Creek intakes 75 . The city would use its CBT water only by exchange until the Boulder
Reservoir WTF was completed in 1971.
In 1963, the city constructed the Betasso WTF for dual purposes: first to address ever-tightening
drinking water standards and increased knowledge of water-borne pathogens following years of
minimal treatment for the Silver Lake Watershed water, and second to increase Boulder’s water
supply by obtaining water from Middle Boulder Creek through PSCo’s facilities. Land for the
treatment facility was purchased from Ella Rhea Newsome 76 . 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 re-plumbed 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 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.
3.2.2.11 | DEVELOPMENT OF THE WINDY GAP PROJECT
Population continued to grow in Boulder, as it did throughout the northern Front Range. In the late
1960’s, a coalition of six Front Range cities – Boulder, Estes Park, Fort Collins, Greeley, Longmont and
Loveland – cooperated in a study of growth, water supply, and demand projections 77 . They
concluded that a new water supply project was necessary to specifically meet municipal needs. The
cities began the development of the Six Cities Project to pursue trans-mountain diversions to meet
those needs. In 1969, the six cities realized that the amount of work and expertise necessary to build
the project required a stronger organization than they could provide independently. They petitioned
the District Court in Greeley for the formation of a Municipal Subdistrict with the NCWCD 78 . The
formation of the Subdistrict was approved on July 6, 1970 and began development of what was
now called the Windy Gap Project 79 .
A proposed project was developed in which the Windy Gap Reservoir, located near Granby on the
West Slope, would divert water from the confluence of the Fraser River and the Colorado River. The
water would then be pumped up to Lake Granby and delivered to Windy Gap Project participants
through the CBT system. After its formation, the Subdistrict 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 northeastern Colorado cities through the CBT project 80 . The Carriage Contract that was
executed in October 1973 allowed the Windy Gap Project to use excess capacity in the existing CBT
storage and conveyance facilities, which made the project economically and environmentally viable 81 .
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In the summer of 1975, the Subdistrict entered into water allotment contracts with each of its six
member cities. Each retained a one-sixth share in the project, equivalent to 80 units out of the total
480 units in the project. The Windy Gap Project was anticipated to deliver an average of 48,000
acre-feet of water annually, diverted primarily during the runoff season between April and July.
Bonds were sold by the Subdistrict to finance the project. Project costs are discussed in more detailed
in section 4.3.2.1. Construction of the project began in 1981 and the facilities became operational in
the spring of 1985.
There was opposition from West Slope representatives regarding the effect of the Windy Gap
Project on water users of the West Slope. Opposition resulted in lengthy litigation along with
extensive environmental impact assessment and mitigation processes. Litigation terminated with the
1980 Windy Gap Settlement Agreement in which the Subdistrict agreed to provide up to $15 million
for the study and construction of the Azure Reservoir Project as a means to compensate for any
impairment of West Slope water use by the Windy Gap Project 82 . In 1985, the Subdistrict and the
Colorado River Water Conservation District reached a supplemental agreement that the Azure
Reservoir Project was infeasible and should not be further pursued, and instead, the Subdistrict would
pay the Colorado River Water Conservation District $10.2 million so it could construct an alternative
storage project for western slope water users 83 . In 1995, the Colorado River Water Conservation
District completed construction of this storage project – Wolford Mountain Reservoir – on Muddy
Creek 84 .
3.2.2.12 | CITY’S PERPETUAL RIGHTS TO USE OF BARKER RESERVOIR
In 1982, a storage restriction was placed on Barker Reservoir by the Federal Energy Regulatory
Commission due to concerns about the ability of Barker Dam to withstand an over-topping event from
flooding. Over-topping concerns have since been addressed and alleviated with dam anchors. A new
agreement was signed with PSCo in 1984 whereby the city partially paid for repairs to stabilize the
dam and gained an “equitable servitude,” a perpetual interest allowing on-going use, in 8,000 acre-
feet of storage space and in two-thirds of the capacity in the Barker pipeline facilities 85 .
3.2.2.13 | CITY HYDROPOWER DEVELOPMENT
In the early 1980s, the city began to develop plans for hydroelectric plants that would generate
electricity using the high pressures developed within the city’s source water and treated water
systems. 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 households.
In 1984, the city negotiated a power sales agreement with PSCo for three proposed hydroelectric
projects on the city’s raw water transmission pipelines—Betasso, Lakewood and Silver Lake Hydros 86 .
This agreement was negotiated at the same time as the agreement whereby the city would pay for
repairs to Barker Dam discussed above. As a result, the city was able to get very favorable payment
terms for the power to be generated once the hydros were built.
During 1986 and 1987, Kohler, Orodell, Sunshine and Betasso hydroelectric facilities were
completed. The Silver Lake Hydro was completed in 1998, and the Lakewood Hydro went into
operation in June 2004. In 2007, the city generated over 41.5 million kilowatt-hours of electricity or
enough to meet the annual needs of about 7,500 Boulder households 87 .
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By a Council decision, the hydro plants on the treated water system were constructed by the water
utility with water utility enterprise funds. The hydro plants on the raw water system were initially to
be constructed with general fund money. General obligation bonds were sold 88 and the money was
used to construct Betasso Hydro in 1987. Subsequently, federal law changed and no additional
general obligation bonds could be sold to fund Lakewood and Silver Lake hydros. Council decided
that the general fund would sell ownership of Betasso Hydro and the undeveloped Lakewood and
Silver Lake projects to the water utility enterprise 89 . Water utility funds were then used to construct
Lakewood and Silver Lake hydros. Accordingly, all income from the hydro facilities is water utility
enterprise fund revenue.
3.2.2.14 | CREATION OF THE BOULDER CREEK INSTREAM FLOW PROGRAM
In 1989, Boulder’s Raw Water Master Plan identified a goal for the city of achieving instream flows
in main Boulder Creek and its tributaries. In July of 1990, an agreement was completed between
Boulder and the Colorado Water Conservation Board (CWCB) and was amended in 1992 90 . The
agreement conveyed water and water rights owned by the city to the CWCB for use for instream
flow purposes (see Table 5-7 for a list of water rights) . Boulder and the CWCB were joint applicants
to the Water Court for a change in use of the water rights and storage decrees to allow instream
flow. This application was filed in December 1990. A decree approving the change was signed on
December 20, 1993 91 . The city has operated the instream flow program as an agent of the CWCB
since that time.
3.2.2.15 | PURCHASE OF THE BOULDER CANYON HYDROELECTRIC PROJECT
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 late 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 city purchased the Boulder Canyon
Hydroelectric Project, including Barker Reservoir, in 2001 with revenue generated from the sale of 43
Windy Gap units to the city of Broomfield. In late 2000, prior to the city’s purchase, the windings on
one of the generator units at Boulder Canyon Hydro Plant grounded out, causing extensive damage
to the generator and leaving it inoperable. Only one turbine-generator unit is currently functioning in
the plant. In addition to the facilities, the city also acquired the associated hydropower water rights. The
city continues to use these rights for hydropower generation and has obtained additional water rights for
storage of municipal water in Barker Reservoir. 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 benefit is
the continued generation of hydropower and the revenues earned by the city from selling the power
to Xcel Energy. The Barker System continues to generate electricity when water is available.
3.2.2.16 | RECONSTRUCTION OF THE AGING WATER SYSTEM
During the 1990’s and early 2000’s, the city focused on re-building much of the aged raw water
delivery system infrastructure. The outlet works and part of the dam at Lakewood Reservoir and the
dam at Goose Lake were rebuilt, along with the two diversion structures from North Boulder Creek.
The Como Creek diversion was also rebuilt. Lakewood and Silver Lake Pipelines were reconstructed.
Following purchase of the 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
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remaining operational turbine and generator at the hydro plant. In Boulder Reservoir, the intake from
the reservoir to the treatment plant was modified to draw water in from a higher elevation to
improve water quality.
Boulder Water System Timeline
1875
Town of Boulder Ditch was constructed to carry water from Boulder Creek into the town’s new
water system. Town of Boulder 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.
1877
Boulder’s first water supply protection ordinance was passed stating, “No person shall put any
carcass or filthy 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.”
1879 Town of Boulder Reservoir capacity was inadequate to serve the growing population and the
town sometimes ran out of water.
1884 Water running in Boulder’s water system was turned off when dead horses were found in Boulder
Creek above the town’s intake.
1887
J.P. Maxwell and George Oliver formed the Silver Lake Ditch Company to provide water to their
new development on Mapleton Hill following Boulder’s refusal to provide municipal water service.
They built the Silver Lake Ditch west of town and a dam at Silver Lake below the Arapaho
Glacier.
1890
A new reservoir, Sunshine Reservoir, was built at an elevation 100 feet higher than the Town of
Boulder Reservoir. The Blanchard intake was constructed upstream on Boulder Creek at Orodell.
J.P. Maxwell built Island Lake to serve the Silver Lake Ditch Company.
1902
Planning began for avoiding creek pollution by building a system of reservoirs and pipelines at a
higher point in the watershed above mining activity. Boulder rejected J.P. Maxwell’s proposal to
build the new water system as a public-private partnership. Water use restrictions were instituted
because of drought.
1904 The first land for what will become the Silver Lake Watershed was purchased near the
Continental Divide, including Triple Lakes and Oval Lake.
1906
Lakewood Reservoir was built near Nederland. Lakewood Pipeline was completed at a cost of
$155,000 to carry water from Lakewood Reservoir to Boulder. Boulder purchased Silver Lake
and Island Lake Reservoirs from the Silver Lake Ditch Company which was owned by J.P. Maxwell.
1907
The federal government issued the first of three grants that allowed Boulder to purchase 1,557
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
to
1910
Barker Meadow Dam and the Boulder Canyon Hydroelectric Plant were constructed by an electric
power company that is later purchased by PSCo.
1911 The city purchased a mining camp at Albion. Construction began on Albion Reservoir.
1913 The construction of Albion Reservoir was completed.
1914
Following outbreaks of typhoid fever, City Council discussed hiring guards for the Silver 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 fenced and closed
by 1920 and a watershed caretaker was hired.
1917
Boulder’s first “water treatment plant” was built near Lakewood Reservoir consisting of a shed
where chlorine and aluminum sulfate were dumped 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. A second grant was
issued by the federal government allowing Boulder to purchase 400 acres of land to add to the
Silver Lake Watershed.
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Final - April 2009 Page 3-17
1925
Boulder completed its first water rights change of use proceeding and the court granted the city
the right to use water within the municipal water system that had previously been decreed for
agricultural use through the Anderson and Farmers Ditches.
1927
Congress approved Boulder’s purchase of 3,689 acres of federal land including Arapaho Glacier
and 4 peaks along the continental divide for $4,618. The deed to the city 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 for the city. Silver Lake Ditch
Company later objected to the city’s alteration of the dam.
1935 The city purchased Green Lakes. Civilian Conservation Corps crews worked in the Silver Lake
Watershed.
1937
Northern Colorado Water Conservancy District was formed to contract with the Bureau of
Reclamation to bring water from the western slope as a supplemental supply for northeastern
Colorado.
1939 Work was started on the reconstruction of Lakewood Pipeline. The project was suspended due to
a shortage of steel during WW II and was not completed until 1954.
1940 Silver Lake dam was rebuilt.
1949
Chlorine was added to water year-round at Lakewood Reservoir instead of seasonally. Studies
showed that increased water needs of Boulder’s large post-World War II population would
exceed Boulder’s existing water supplies.
1953 Boulder became a member of the Northern Colorado Water Conservancy District and acquired
contract water delivery rights for the CBT Project.
1954
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 exchange water from
Baseline Reservoir into Barker Reservoir for later release in exchange for direct diversions at
Lakewood Reservoir. Silver Lake Pipeline was rebuilt using 1906 pipe salvaged from the
Lakewood Pipeline reconstruction.
1955
Boulder Reservoir was built and filled from Carter Lake with CBT water diverted from the western
slope. Boulder entered into an agreement with PSCo allowing on-going city use of 4,000 acre-
feet of storage space in Barker Reservoir.
1959 The Barker Reservoir agreement with PSCo was revised to allow Boulder use of 4,000 acre-feet
of storage space to be increased to 8,000 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.
1969
Fluoridation of drinking water was approved by Boulder voters.
Six northeastern Colorado cities, including Boulder, initiated the Windy Gap Project to deliver
municipal water through CBT facilities.
1971
Boulder Reservoir Water Treatment Facility was built with a capacity of 8 MGD. CBT 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 8,000 acre-feet.
1976 Betasso Water Treatment Facility was doubled in capacity to 45 MGD.
1982 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.
1983 A contractor working at Goose Lake caught the timber cribbing on fire and the upper portion of
the dam burned.
1984
The first hydroelectric plant on Boulder’s water system was built. Boulder entered into an
agreement with PSCo allowing the city to permanently use 8,000 acre-feet of storage space in
Barker Reservoir.
1986 Efforts to reach an agreement with the USFS for the reconstruction of Lakewood Pipeline began.
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1989 The city completed the Raw Water Master Plan and adopted reliability criteria for the raw water
supply system.
1990 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 Boulder sold 43 units out of its 80 units of Windy Gap water to the city of Broomfield.
1993 A 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, the inlet to Lakewood Pipeline, and the part of the dam over Lakewood
Pipeline were rebuilt in 1996.
1995 Extremely 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 The upstream face of Goose Lake dam was rebuilt. The reconstruction of Silver Lake Pipeline was
completed.
2001
Barker Reservoir and Boulder Canyon Hydro Project facilities were purchased from PSCo for
$12.4 million. Work to repair the Barker Gravity Line began. An easement agreement for the
Lakewood Pipeline was signed as a result of 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 be
implemented in Boulder. Water use dropped by 20 percent.
2004
The Lakewood Pipeline reconstruction was completed and the new pipeline went into service along
with Lakewood Hydro. With the completion, the city, through its water utility, owns and operates a
total of eight hydro plants.
3.3 | Management of Irrigation Ditches
3.3.1 | IRRIGATION DITCH BACKGROUND
Much of the land within the present Boulder city limits was once farmland irrigated by irrigation
ditches. Many of these ditches are still in existence and carry irrigation water through the urban areas
for use on private yards, parks, campus areas, or farmland at the edge of the city or as far as Weld
County. There are over twenty irrigation ditches spanning over thirty miles within Areas I and II as
defined in the Boulder Valley Comprehensive Plan 92 (Table 3-1). Within Areas I, II, and III, there are
more than thirty irrigation ditches (Figure 3-1).
TABLE 3-1. PARTIAL LIST OF IRRIGATION DITCHES WITHIN THE BOULDER VALLEY
Ditch Ditch Water Source Ditch Water Source
Anderson Ditch Boulder Creek Jones and Donnelly Ditch South Boulder Creek
Boulder and Whiterock Ditch Boulder Creek Leggett Ditch South Boulder Creek
Boulder and Lefthand Ditch Boulder Creek McCarty Ditch Boulder Creek
Boulder Feeder Canal CBT/Windy Gap McGinn Ditch South Boulder Creek
Butte Mill Ditch Boulder Creek North Boulder Farmers Ditch Boulder Creek
Dry Creek No. 2 Ditch South Boulder Creek Schearer Ditch South Boulder Creek
East Boulder Ditch South Boulder Creek South Boulder Bear Creek Ditch South Boulder Creek
Enterprise Ditch South Boulder Creek S. Boulder Canon Ditch South Boulder Creek
Farmers Ditch Boulder Creek Silver Lake Ditch Boulder Creek
Green Ditch Boulder Creek Smith and Goss Ditch Boulder Creek
Howard Ditch South Boulder Creek Star Ditch Left Hand Creek
Howell Ditch Boulder Creek Wellman Ditch Boulder Creek
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
FIGURE 3-1. DITCHES WITHIN BOULDER VALLEY
Final - April 2009 Page 3-19
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-20
3.3.2 | MAINTENANCE OF IRRIGATION DITCHES
Irrigation ditches are owned and maintained by private ditch companies, most of which operate
under the provisions for mutual ditch corporations in the Colorado statutes 93 . Shareholders in the
companies pay assessments for operation and maintenance of the ditches and are entitled to receive
a pro-rata portion of the water carried in the ditch based on their ownership of ditch company
shares.
The city is a shareholder in many of these companies, but its shareholder rights are no different than
those of the private shareholders. The ditch company remains a private corporation even if a portion
of its shares are owned by the city. In many locations where city transportation 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. Boulder’s Public Works
maintenance group has a database to track transportation and utility maintenance activities, including
work performed on ditches.
In general, the active ditches within the city are in good to fair condition. There are a few ditch
locations where the facilities are in disrepair with significant leakage and are in some danger of
collapse. 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
are no longer used to carry irrigation water can still be seen.
3.3.3 | IRRIGATION DITCHES AND URBAN ENCROACHMENT
Although many residents refer to the irrigation ditches as “creeks” and believe they are natural
waterways, irrigation ditches have distinct differences from natural streams. Ditches are constructed to
run perpendicular to the slope of the land rather than down the slope, as is the natural course for
streams. The ditches were constructed in this manner to transport water as far as possible away from
the stream and to allow irrigation of the greatest amount of land below the ditches. This configuration
results in an unnatural 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 are periodically
sealed to minimize seepage, particularly in urban areas. Ditch companies are not generally liable for
damages from what is considered normal seepage, especially to buildings constructed down-slope of
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 arise by use of the land for the given purpose over
time. Under Colorado law, “open and notorious” use for a specific purpose for a period of eighteen
years creates a prescriptive easement that is binding on the underlying property owner. These
prescriptive easements are rarely recorded on public records, so new property owners often do not
understand 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
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easement is the “dominant estate”94 . In addition, there are 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 are not limited to a certain width, but instead include the right to access for
whatever activity is “reasonable and necessary” to operate and maintain the facility. This is often
defined by the easement owner’s historical use practices. For ditch companies, this usually includes
access to the ditch for ditchridersiii 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 95 . 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 trees or bushes adjacent to the ditch, the ditch company often has no
obligation to protect the structure or landscaping if they are damaged or must be removed during
ditch maintenance activities even if they have existed for many years. Property owners with an
irrigation ditch running across their land should not move or alter the ditch without the permission of
the ditch company 96 .
Properties on the down-slope side of a ditch 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 responsibility of the property
owner to install seepage protection for the improvements made after the ditch was in existence.
Likewise, it is usually the property owner’s responsibility to remove any dead or dying trees near the
ditch bank, although the ditch company has the right to remove any vegetation that interferes with
ditch operations97 . 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 property owner may then have liability for any ditch overtopping, seepage or flooding caused
by these actions. In order to minimize conflicts, the city 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. Boulder’s Utilities Division and Planning and Development Services have
been working closely in recent years to develop a protocol to protect ditches from urban
encroachment and protect developments from the effects of potentially high water tables. When
residents seek a building permit for a permanent structure near an existing ditch bank, the city may
require that the residents receive approval from the ditch company to assure that the company’s
easement rights are not affected.
3.3.4 | STORMWATER AND IRRIGATION DITCHES
Irrigation ditches naturally intercept a large amount of stormwater and natural drainage from the
upslope areas above the ditches due to their alignment along a line perpendicular to the slope of the
land. In addition, irrigation ditches were often constructed to capture streamflow from gulches and
intermittent streams crossed by the ditch in order to increase the ditch water supply. Due to these ditch
characteristics, the amount of water flowing in an irrigation ditch often can increase quickly during
storm events and may cause flooding of properties downslope of the ditch if the ditch bank is over-
topped. It is also possible for stormwater to be carried from one small stream basin into another and
cause flooding where it might not otherwise have occurred.
iii “Ditchrider” is the traditional term used for the person who operates and maintains an irrigation ditch for a ditch company. It is
derived from the time when ditch personnel would ride horses along the ditch bank to monitor the ditch.
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In many cities of Boulder’s age, no storm sewer system existed until the twentieth-century because
typical nineteenth-century city planning processes did not have any standards for dealing with
concentrated stormwater discharges from developments and paving of roads. Drainage water was
allowed to simply flow downstream however it could. By the time the city began constructing a storm
sewer system, a significant portion of Boulder had already been built. In the 1920s, the city
developed a plan to pave its streets and build storm sewers in the north-to-south running streets. If the
storm sewer intercepted an irrigation ditch before reaching a natural stream channel, the city allowed
the pipe to discharge to the ditch.
In 1923, the Boulder and Whiterock Ditch Company sought to prevent the city from discharging
stormwater into the ditch from a newly constructed storm sewer that ran along 16th Street. The city
had plans to construct additional storm sewers that would discharge to the ditch, and the ditch
company sought to enjoin their construction. The company also contended that the stormwater polluted
the ditch water and made it unsuitable for domestic use 98 . The Boulder and Whiterock Ditch diverts
from Boulder Creek east of Broadway (the 12th Street Diversion) and runs north-easterly through the
city. The ditch was constructed to intercept streams that it crossed, including Goose Creek and
Wonderland Creek. The company has a decreed water right for agricultural use for diversions from
Boulder Creek and Goose Creek and claims rights, though undecreed, to other streams that the ditch
intercepts. The trial court ruled that the city had seven months to remove the 16th Street stormwater
discharge and that any stormwater pipe discharge above the ditch, even if the water would have
reached the ditch under natural conditions, was a trespass and nuisance. The ruling was appealed to
the Colorado Supreme Court, which overturned the lower court ruling. The Supreme Court held that
the ditch company had no cause for complaint against the city for merely collecting and accelerating
stormwater discharge into the irrigation ditch if the ditch was constructed in such a way that it would
otherwise naturally intercept the same surface drainage. Furthermore, the city could not be held
liable for nuisance based on pollution of domestic water supplies because the ditch company’s water
rights were only decreed for irrigation purposes, which the city had not made any less valuable
through its actions 99 .
Following several large flood events in the Denver metropolitan area in the late 1960s, including a
major flood on Bear Canyon Creek in Boulder, the Urban Drainage and Flood Control District
(UDFCD) was formed to coordinate efforts of metro Denver cities to construct and operate regional
flood control and drainage facilities. UDFCD established standards for dealing with increased runoff
from new construction that included directing runoff to natural channels and ending reliance on
intervening drainage ditches. Almost all new developments built after that time drain to natural
channels. However, irrigation ditches still intercept a great deal of stormwater either due to their
construction across the lay of the land or due to older development.
Boulder’s Stormwater Master Plan includes plans to lessen the stormwater inflow into irrigation ditches
over time. However, the amount of remedial work that must be done to address this problem as well
as address under-sized or non-existent drainage channels and stormwater system pipelines is large
given that decades of development occurred in Boulder with very little thought given to stormwater
management and no engineering design standards existed for decades after that. Therefore, the
capital investments required for the city’s stormwater system are large and will need to be spread
out over many years. The existing situation with large amounts of stormwater entering into irrigation
ditches is likely to continue for a long time.
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The Anderson Ditch intercepts and carries large amounts of stormwater that is generated from
University Hill in the area south of Boulder Creek, east of Broadway and north of Bear Creek. Since
this situation is likely to continue for a long time into the future, given the greater need to address
parts of the city that have no stormwater drainage facilities at all, the city has signed an agreement
with the Anderson Ditch Company to carry city stormwater through its facilities. The city pays the ditch
company an annual assessment for stormwater carriage. 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 100 .
Other ditches running through the city also receive stormwater discharges throughout their length.
However, the city has not entered into any other ditch-wide stormwater carriage agreements because
these other ditches are not as heavily impacted by storm drainage as is the Anderson Ditch. The city
has entered into agreements with other ditch companies regarding specific areas of the ditch that
may be impacted by changes in historic storm drainage. For example, the city entered into an
agreement with the Farmers Ditch Company regarding the area around the North Boulder Recreation
Center so that stormwater discharges from the site could be increased over historic levels 101 .
The city and the Farmers Ditch Company have an agreement that allows the city to carry “foreign”
water from other sources through Farmers 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 102 .
3.4 | Legal Factors Affecting Water Management
The city of Boulder operates its water supply system within the legal boundaries of court decrees,
state laws, state constitutional provisions, federal laws, contracts, the City Charter and City Council
adopted plans and policies. This legal framework both guides and constrains the activities the city
conducts through the water utility. This SWMP assumes that any legal constraints will continue in the
future. No recommendation will be made for an action that is contrary to a legal constraint without
noting in the recommendation that the legal constraint must first be removed.
3.4.1 | COLORADO WATER LAW
Understanding the city’s water rights requires some familiarity with Colorado’s basic water law
doctrine, the prior appropriation doctrine, often summarized as “first in time, first in right.” The prior
appropriation doctrine is the basis of a property rights-based water allocation and administration
system that 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. No more water
can be taken than can be beneficially used. This system imparts security by defining and protecting
the right to use water and providing a predictable method of water allocation during dry periods. It
provides reliability by giving assurance that the right to use water will continue to be recognized and
enforced over time as a vested property right. The system is flexible because water rights are
separate property from the land on which the water is used. They may be bought, sold or changed to
another type of use through court proceedings so long as no other water rights are adversely
affected or “injured.” See section 3.2.1 on the history of Colorado water development for more
historical information on Colorado water laws.
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A water right in Colorado is characterized by several factors. These include its priority date (based
upon both the date on which the right was first appropriated, i.e., put to beneficial use or work begun
on the water diversion project, and the date the appropriation was confirmed by court decree),
decreed rate of diversion or volume of storage, decreed uses (such as municipal or agricultural),
location of its diversion point, association with delivery facilities or storage reservoirs, water quality,
institutional restrictions on use, whether water remaining after the first use can be reused, and market
competition for purchase of water. Although a right to use water can exist without benefit of a court
decree, a water right must have received a decree through an adjudication process with the court to
have a priority date that will be recognized and administered against other water rights by the State
Engineer’s Office (SEO).
3.4.1.1 | USE OF WATER RIGHTS
The SEO administers all water rights within each river basin according to the priority system. For this
purpose, Colorado is divided into seven water divisions, corresponding to the major river basins in the
state. For purposes of allocating administration duties, these water divisions are further subdivided
into water districts which encompass local sub-basins. An SEO employee called a “water
commissioner” is assigned to each water district to regulate who is allowed to take water along with
when and in what amount. The Boulder Creek sub-basin, which includes Boulder Creek and its
tributaries, makes up Water District 6, which lies in Water Division 1, the South Platte River Basin.
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 streamflow to
allow all other more senior water rights to concurrently be fully satisfied. The most senior water rights
can usually divert at most times during their historical or decreed season of use while more junior
water rights often can only divert during high flow periods. In the South Platte River Basin, the most
senior water rights are those with priorities in the 1860’s and 1870’s. A water right is “in priority”
when there is sufficient flow to allow it to legally divert water. Otherwise, the diversion is “out of
priority,” meaning the right cannot legally divert water. If a water right is not being satisfied at a
time when more junior rights are diverting, the water right owner can place a “call” against the junior
right and cause it to stop taking water; this is known as being “called out” of priority. Following
application of the water to beneficial use, as defined by the conditions of the water right decree, any
remaining unconsumed water must be allowed to return to the stream for diversion by downstream
water rights, unless the decree specifically allows reuse of the unconsumed water.
3.4.1.2 | TYPES OF WATER RIGHTS
Water rights are initially decreed as either direct flow water rights or storage water rights. Direct
flow water rights are those that must be used immediately for their decreed beneficial uses, without
storage. Storage water rights are those that can be stored first and subsequently placed to their
decreed beneficial uses. Water rights that are initially decreed as direct flow water rights can be
changed with court approval to allow both direct flow use and storage with subsequent use. This
oftentimes occurs when agricultural direct flow water rights are changed to municipal use. Beneficial
uses for water rights are not expressly defined or limited under Colorado law, but can be any use
that is reasonable, lawful and not wasteful. Recognized beneficial uses include exchange for use of
other water and augmentation of out-of-priority diversions. An exchange use allows the holder to
satisfy senior water rights by adding water to a stream from a downstream source in exchange for
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diversion of an equal amount of water upstream. An augmentation use is usually made as part of a
court-approved augmentation plan which allows a junior water user to replace depletions to senior
water rights with water from another source, so that diversions under the junior right can continue at
times when the right is out of priority.
The facilities required to divert and 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 confirmed by the water court. Under these circumstances, the right is decreed as “conditional,”
and will be made absolute after proof is made in water court that actual diversion and beneficial use
of water have taken place under the water right 103 .
3.4.1.3 | WATER LAW PRINCIPLES AND ADJUDICATION PROCEDURES
Water law principles may be established through legislative action or through court decrees. The
implications of a particular water law principle may be complex, so simplified terminology based on
phrases from a statute or decree often develops to describe a particular concept.
An example is “Expansion of Use.” A water right owner is generally not allowed to make new uses
not previously decreed for a water right or to increase the consumptive use associated with the
decreed uses of a water right beyond the limits of the historical consumptive use or, in the case of
conditional water rights, beyond the contemplated consumptive use of the water right. The reason
behind these principles is that return flows from one use provide the water to fulfill another user’s
water right. A downstream water user would be injured if the amount of water consumed under an
upstream water right increased. In this way, water reuse is built into the prior appropriation system,
even if an individual water user does not have reuse rights.
A water user may have several water rights with flow rate amounts that when added together
appear, on paper, to allow diversions in excess of current needs. In reality, these rights may not be in
priority at the same time or may be sufficiently junior that they only yield water for a few weeks
during high runoff periods. Beneficial use principles and requirements prevent more water from being
taken than is necessary to satisfy the water right owner’s immediate needs. Similarly, under decreed
use principles and requirements a water user must be able to take water into a decreed structure for
decreed purposes to claim the water or else no longer has any right to the water and must allow it to
pass by to other water users. For example, if a city has a pipeline with capacity larger than its
immediate municipal needs, the city cannot increase diversions under its direct flow rights for other
purposes beyond municipal needs. Conversely, if a pipeline is flowing full, yet only meeting part of a
city’s needs, and the city still has direct flow rights in priority, the additional water that cannot
physically fit into the full pipeline can only be taken by the city at another diversion point if that point
is included in the decree. The city cannot use the additional water flowing past the full pipeline for
other undecreed purposes.
The owner of a water right can change the terms of the decree governing its use by filing an
application with the water court and obtaining approval of the proposed changes. Filings for new
water rights can be made in the same manner. The court publishes a resume of all filings received
monthly. Anyone concerned that a filing may reduce the yield or otherwise injure their water right
may file an objection to the application no later than the end of the month after the month of the
publication in the resume. The applicants provide information to the objectors. If concerns can be
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resolved, the objector may stipulate to terms and conditions to be placed on the applicant’s water use
that will be included in a court decree. If concerns cannot be resolved, then a trial may be held
before a Water Judge who is well-versed in water law and water issues. Almost all water court cases
are settled between the parties and very few go to trial.
Water diverted under a particular water right must be put to use for the decreed purposes. A change
in use requires approval by the water court. For example, when Boulder dedicated use of
municipally-decreed water to the Colorado Water Conservation Board (CWCB) for instream flows in
Boulder Creek, a court proceeding was required. See section 3.4.9.1 for a description of the instream
flow program. It was necessary to set new terms and conditions on the city’s existing water decree to
limit municipal use under the decree in order to provide water for the new purpose 104 .
Reductions in municipal water use that may be temporary, such as through water conservation
programs, cannot become the basis for transferring water to another non-municipal use without water
court approval. To obtain such approval, the city would likely be required to make a permanent
commitment to reduce current water use under the designated municipal right. Changes of water
rights are frequently likened to an IRS tax audit and almost always result in new terms and conditions
on use of the water rights. Thus future changes of water rights by the city from municipal to other non-
municipal uses could reduce the remainder of the water right yield below historical municipal use
levels.
3.4.2 | WATER UTILITY ENTERPRISE FUND
The city provides water, sewer and stormwater services by virtue of Article XX of the State
Constitution 105 (Home Rule of Cities and Towns) and the City Charter 106 . The Utilities Division of the
Public Works Department directs the day to day operations of the three utilities. The city operates its
water, sewer, and stormwater systems as individual “enterprises” as defined in Section 11-1 of the
City Code and Article X, Section 20 of the State Constitution. This portion of the constitution was
amended in 1992 when Colorado voters approved the Taxpayer’s Bill of Rights (TABOR). This
amendment was designed to restrain growth in government. TABOR limits revenue growth for state
and local governments in Colorado and requires that any tax increase in any state or local
government must be approved by the voters of the affected government. Designated enterprise
funds are exempt from the revenue constraints imposed by TABOR.
The TABOR revenue limit restricts the growth of all general funds and all cash funds. The revenue that
a government entity can retain within these funds from all sources, except federal funds, in a year is
limited to the amount of the previous year’s collections which were allowed under TABOR (not actual
collections) plus a percentage adjustment equal to the percentage growth in population plus the
inflation rate. If the revenue collected from all sources exceeds the limits of the formula, it must be
refunded to taxpayers unless voters grant prior approval to retain and spend the excess funds.
TABOR includes in the definition of revenue all general funds, such as revenue collected from taxes,
and cash funds, which are generally restricted funds, generated by fees or fines, which can only be
used for the purpose or program for which the fee is collected. The types of revenue that are exempt
from TABOR restrictions include federal funds, litigation settlements, gifts, and money earned by
enterprises. TABOR narrowly defines “enterprise” as any government-owned entity with bonding
authority that receives less than 10 percent of its total funding from all grants from Colorado state or
local governments combined 107 . While both cash funds and general funds count toward the city’s
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fiscal year spending limit, all excess revenues are refunded out of the general fund. Therefore, if the
city’s water utilities fund was not exempt as an enterprise fund and water sales revenue in any year
drove the city over the TABOR revenue limit, the excess would need to be refunded from the city’s
general operating budget.
Accordingly, there are distinct benefits both to enterprise funds and to the city’s general fund from
assuring that the enterprise fund status is not jeopardized. In order to maintain enterprise fund status,
each of the three separate city utility enterprise funds must limit both their sources of revenue and the
activities on which the revenue is spent. For example, revenue earned by the city that is accounted for
within the water utility enterprise fund is mostly derived from water sales and fees for allowing taps
into the city water system. This revenue is tracked separately within the city’s accounting systems from
the general fund or other restricted funds and must be used for activities related to providing the
municipal water supply. Likewise, the assets held within the water utility enterprise fund, such as the
city’s water rights that provide the water for municipal use, must be used for the principal purpose of
providing this service.
Money is transferred from the water utility enterprise fund to the general fund to pay for specific
services provided by general fund departments that are needed to support water utility operations,
such as human resources support or city attorney services. Under the City Charter, other city
departments do not pay the water utility enterprise fund for provision of a reasonable amount of
water supply to meet their needs, but do pay Plant Investment Fees for water taps into the city system
and pay for water usage in excess of what is reasonable. If an asset that is included within the asset
list for the water utility enterprise fund, which forms the basis for the Plant Investment Fee calculation,
were to be committed to permanent use by another city department, it would no longer be available
for the primary purpose of providing municipal water supply. Therefore, that asset would need to be
“purchased” from the water utility enterprise fund through transfer of money out of funds available to
the city department gaining benefit of the re-assigned asset.
The Boulder Revised Code 108 (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 grants from all Colorado state and local
governments 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 11-1-55:
“In addition to any of the powers it may have by virtue of any of the applicable provisions of
state law, the City 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, wholly within or wholly
without the city or partially 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 rights, lands,
easements, and rights in land in connection therewith;
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(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 boundaries of the
city;
(c) To accept federal funds under any federal law in force to aid in financing the cost of
engineering, architectural, or economic investigations or studies, surveys, designs, plans,
working drawings, specifications, procedures, or other action preliminary to the construction of
water facilities;
(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 arrangements with consumers
concerning water facilities, whether acquired or constructed by the water utility enterprise or
the consumer, and to accept grants and contributions from consumers for the construction of
water facilities;
(f) 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 charges or any combination thereof for the services furnished 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 finance in
whole or in part the cost of acquisition, construction, reconstruction, 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 11-2,
“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 contracts and agreements with other governmental entities and
utility enterprises for or concerning 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 its 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 utility 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 city is
thereby incurred in any manner for any purpose; and
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(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 arrears 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 appertaining to the issuance of
additional bonds or to any municipal water and wastewater facilities.”
3.4.3 | SAFE DRINKING WATER ACT
The Safe Drinking Water Act (SDWA) was originally passed by Congress in 1974 to protect public
health by regulating the nation’s public drinking water supply 109 . The law was amended in 1986 and
1996 and requires many actions to protect drinking water and its sources, including rivers, lakes,
reservoirs, springs, and ground water wells iv . The SDWA authorizes the United States Environmental
Protection Agency (US EPA) to set national health-based standards for drinking water to protect
against both naturally-occurring and man-made contaminants that may be found in drinking water.
The agency in charge of water quality in Colorado is the Colorado Department of Public Health and
Environment. US EPA, states, and water systems work together to make sure that drinking water
standards are met.
Originally, the SDWA focused primarily 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, the SDWA 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 standards. Water systems treat the water and must test their water frequently for
specified contaminants and report the results to states. If a water system is not meeting these
standards, it is the water supplier’s responsibility to notify its customers. Many water suppliers,
including the city, are also required to prepare 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 drinking water sources. Water systems across the
nation rely on citizen advisory committees, rate boards, volunteers and civic leaders to actively
protect this resource in every community in America.
3.4.4 | SOURCE WATER ASSESSMENT AND PROTECTION PROGRAM
Source water protection is the crucial first barrier against contaminated drinking water and focuses on
actively keeping contaminants out of existing and future source water supplies. This is accomplished
by reducing or eliminating human activity in and around water supplies, constructing protection
barriers between existing land use activity and the water supply, or isolating the source water from
contamination within an enclosed structure. The Safe Drinking Water Act has mandated source water
iv SDWA does not regulate private water systems that serve fewer than 25 individuals.
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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
(SWAP)110 . SWAP has five essential elements:
watershed delineation, including trans-basin diversions;
inventory of all actual and potential sources of contamination, including the name and address of
polluters where known;
determination of susceptibility of a public water supply to those contaminants;
informing the public of the existence of those contaminants in their drinking water supply through
the annual Consumer Confidence Report, and;
implementing protection of drinking water from those contaminants.
Actual and potential sources of contamination to source waters are to be identified under the SWAP
program, including polluted runoff or potential releases from agricultural and industrial activities,
manufacturing, services (i.e., gas stations, maintenance shops), utilities, roads, accidental and
deliberate hazardous material dumping, residential development, septic systems and recreation
activities. Current regulations require reporting all contaminant sources in each annual Consumer
Confidence Report.
The city of Boulder has actively participated in the state SWAP program and has developed an
internal monitoring program to characterize source water quality and identify sources of pollution.
Detailed maps of the city’s source water watersheds were delineated as part of Phase I of SWAP
program v . Phase II efforts identified the location of potential sources of contamination (PSOCs) in
relation to surface water and treatment plant intakes within the delineated areas. In Phase III of the
SWAP program, the state used computer software to generate PSOC risk and vulnerability
assessments based on information from phases one and two.
3.4.5 | FEDERAL ENERGY REGULATORY COMMISSION
The Federal Energy Regulatory Commission (FERC) holds responsibility through 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 hydroelectric projects (re-licensing), issuing exemptions from
licensing requirements, and oversight of all ongoing hydroelectric project operations within the
defined FERC project boundaries, including dam safety inspections and environmental monitoring 111 .
FERC issues both licenses and exemptions from licensing for hydroelectric facilities based upon a
series of criteria including generation capacity, design and configuration and ownership of affected
lands. The city currently holds seven conduit exemptions from licensing issued by FERC for its Silver
Lake, Lakewood, Betasso, Orodell, Maxwell, Kohler and Sunshine Hydroelectric Projects. Conduit
exemptions apply to hydroelectric projects which use the hydroelectric potential of a conduit that
exists for purposes other than hydroelectric power generation. For example, the city’s exempt
hydroelectric facilities are all located on pipelines or conduits which exist primarily for raw or treated
municipal water transmission. The FERC project boundaries under a conduit exemption are limited to
little more than the turbine-generator and associated equipment. Exemptions from licensing are issued
in perpetuity and contain conditions concerning project operation and maintenance.
v Phase I map of SWAP, source water watersheds, is included in the Appendices.
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Hydropower licenses are issued by FERC for hydroelectric facilities with more than 5 megawatts of
generation capacity, which may include a dam and which generally include more affected area than
small hydropower projects. Licenses are generally issued for a term of 30 to 50 years. The Boulder
Canyon Hydroelectric Project, which includes Barker Dam and Reservoir, is a licensed facility 112 . The
current license, which was issued to PSCo on April 28, 1981, was transferred to the city upon its
purchase of the project in 2001 and will expire on August 31, 2009 113 . Following the city’s purchase
of Boulder Canyon Hydro, the primary purpose for use of the facilities became the provision of
municipal water supplies. Generation of hydropower is now a secondary purpose and the facilities
meet the FERC requirements for a conduit exemption from licensing. The city is following FERC
requirements for authorization to continue operating the Boulder Canyon Hydro after the current
license expires in the form of an exemption from licensing. The city filed a Pre-Application document
in 2007 114 and submitted an application for an exemption from licensing in November 2008 115 .
Dam safety is a critical part of the FERC hydropower program. Prior to construction, FERC reviews
and approves the designs, plans and specifications for dams, powerhouses and other structures. Once
construction is complete, FERC requires continuing project inspection on a regular basis. All licensed
dams are required to have an Emergency Action Plan which must be updated and practiced annually.
3.4.6 | COLORADO RIVER COMPACT
Colorado has legal obligations to provide water to downstream states based on interstate river
compacts, which are both state law and federal law. The Colorado River Compact could have an
effect on the city’s water supplies.
Deliveries of water through NCWCD are affected by the Colorado River Compact of 1922 116 . The
compact divided the basin in half, designating Lee’s Ferry on the Colorado River near the Arizona-
Utah border as the boundary point separating the upper and lower basins (Figure 3-2).
At the time of the compact, it was believed that the average annual flow in the Colorado River above
Lee’s Ferry was 15 million acre-feet. Therefore, the compact apportions an average of 7.5 million
acre-feet per year to the lower basin states, with the remainder, which was believed at the time to
be 7.5 million acre-feet, to the upper basin states. The apportionment is implemented by requiring
that the flow at Lee’s Ferry will not be depleted to less than 75 million acre-feet for any consecutive
10-year period 117 . The result is that the lower basin states of California, Nevada, and Arizona (and
parts of New Mexico and Utah below Lee’s Ferry) are assured a full allocation and any shortages
caused by average flows in the Colorado River basin above Lee’s Ferry being less than 15 million
acre-feet in any ten year period will be borne by the upper basin states of Colorado, Wyoming,
New Mexico and Utah. An additional 750,000 acre-feet of water per year is committed to Mexico-
based treaty obligations.
The Upper Colorado River Basin Compact was signed in 1948 to apportion the allocation allowed to
the upper basin states under the Colorado River Compact. Under this 1948 compact, Colorado
receives 51.75 percent, New Mexico receives 11.25 percent, Utah receives 23 percent, and
Wyoming receives 14 percent of the upper basin states’ allocation under the Colorado River
Compact 118 .
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FIGURE 3-2. UPPER AND LOWER BASINS UNDER THE COLORADO RIVER COMPACT 119
Final - April 2009 Page 3-32
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In 2005, following five years of drought in the Colorado River basin, negotiations began between the
states that were parties to the Colorado River Compact and the Department of Interior to develop
rules for addressing the potential for a shortage under the compact. The Upper Basin states feared
that Lake Powell could run out of water and that the Lower Basin states might push for a “compact
call.” This would force Upper Basin water users that were junior to the compact to reduce water use
or to release water from reservoirs. In December 2007, an agreement called the “Colorado River
Interim Guidelines for Lower Basin Shortages and the Coordinated Operation for Lake Powell and
Lake Mead” was signed that included new equalization guidelines for storage in the two reservoirs,
established shortage criteria for the Lower Basin and started a program to encourage Lower Basin
states to implement water conservation measures that would allow them to stay within their compact
allocations. It is believed that the implementation of this agreement will significantly reduce the
likelihood of a compact call 120 .
3.4.7 | CITY CODE
There are many ordinances contained in the City Code, B.R.C. 1981 121 that affect the water utility.
Most of these ordinances are contained in the following sections:
Section 11-1-13 When Connections with Water Mains are Required
Section 11-1-14 Permit to Make Water Main Connections
Section 11-1-19 Water and Ditch Rights
Section 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 Section 4-20, B.R.C.1981
Most of the ordinances that relate to source water are contained in Section 11-1-19.
Presently, the code requires immediate hook-up to the water utility upon annexation for commercial
or public facilities if structures exist or are proposed and if they are adjacent to a water main.
Private properties 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 are any other properties that enter into a written agreement with the city. See
Section 11-1-13, B.R.C. 1981.
Section 11-1-19 of the City Code addresses transfer of water and ditch rights upon annexation and
subdivision and specific conditions for Silver Lake Ditch. The city has adopted ordinances that require
owners of water and ditch rights to offer to sell their rights to the city at the time of application 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 122 . 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.
Other sections of the City Code cover management of the Silver Lake Watershed and protection of
source water facilities. Section 11-1 (Water Utility) discusses trespass and interference with the
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operations of the water utility 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 patrol officers
“have conferred upon them police powers sufficient to enforce such ordinances.” In addition, Sections
5-4, 5-5 and 5-6 include ordinances regarding 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 $1,000 per occurrence.
The Silver Lake Watershed, which provides approximately 35 percent of the city’s water supply, has
been closed to public access since the 1920s to protect the water source. Reasons for the Silver Lake
Watershed closure policy include:
reduction of wildland fire 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 an 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;
preservation of a rare alpine research site that has on-going research dating back to the
1950s;
protection of greenback cutthroat trout, which are a listed threatened species, and;
insufficient resources and staffing for the water utility to manage recreational activities.
3.4.8 | BOULDER VALLEY COMPREHENSIVE PLAN
Since 1970, the city and Boulder County have jointly adopted a comprehensive plan that guides land
use decisions in the Boulder Valley. The facilities and services section of the Boulder Valley
Comprehensive Plan (BVCP) establishes policies linking growth to service standards and provisions
found in the Source Water Master Plan and other master plans. The following paragraphs of the
BVCP describe the water resources protection policies that relate directly to water supply 123 .
Protection of Water Quality
The city and county shall protect, maintain and improve water quality within the Boulder Creek
basin and Boulder Valley watersheds, as a necessary component of existing ecosystems and as a
critical resource for the human community. Efforts will be made to protect the quality of
groundwater, surface water, and storm water, and to plan for future needs.
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Water Resource Planning
The city and county shall work together and with other government agencies to develop and
implement appropriate water quality standards, water resource allocations, and water quality
protection programs. Water resource planning efforts shall include such things as incorporation of
water quality protection into land use planning, water conservation, and evaluation of pollution
sources.
Drinking Water
The city shall protect the quality of its water sources, and shall meet all Colorado Primary
Drinking Water Standards. It is also the goal of the city to meet Secondary Drinking Water
Standards vi established by the EPA. The city will work with other water and land use interests as
needed to assure the integrity and quality of its drinking water supplies.
Minimum Flow Program
The city shall pursue expansion of the existing instream minimum flow program to protect aquatic
ecosystems within the Boulder Creek watershed.
Protection of Aquifer and Groundwater Recharge Areas
The city and county shall continue to evaluate aquifers, groundwater recharge areas, and sources
of groundwater pollution within the Boulder Creek watersheds and formulate appropriate
protection programs.
Pollution Control
The city and county shall seek to control both point and non-point sources of water pollution
through pollution prevention, improved land use configurations, use of wetland detention areas,
standards to control degradation of streams and lakes caused by storm runoff in urban and rural
areas, and control and monitoring of direct sources of discharge, including those of gravel
extraction and wastewater treatment facilities.
Discouragement of Private Sewage Systems
The city and county support the County Board of Health’s policy discouraging the installation of
private sewage disposal systems where municipal collection systems are available, or where a
potential pollution or health hazard would be created. The city and county will support the
development of programs to monitor problems associated with failing septic systems.
3.4.9 | 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 instream flow purposes and to the Silver Lake
Ditch Company for irrigation use. Water from the CBT and the Windy Gap Projects is delivered to
the city under contracts with the NCWCD. A contract with NCWCD also governs how Boulder
Reservoir is operated. In addition, the city sells power from its hydropower plants to Xcel Energy
vi Limits chemicals that cause aesthetic problems such as taste and odor.
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based on several contracts. The city also enters into annual contracts to lease water that is not needed
for municipal use to local agricultural users. These contracts are discussed in detail below.
3.4.9.1 | COLORADO WATER CONSERVATION BOARD
The city of Boulder, in conjunction with the Colorado Water Conservation Board (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
city’s involvement in 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.
In July 1990, an agreement was completed between Boulder and the CWCB. This agreement was
amended twice, in 1990 and in 1992 124 . This agreement and the amendments convey to the CWCB
a portion of the city’s water and water rights to use for instream flow purposes. The city retains title
to some of the water rights and pays annual assessments to the original ditch companies associated
with the conveyed water rights. The city has the right to use the water and water rights for municipal
purposes under some conditions and owns the right to reuse a portion of the water remaining after
the instream flow use itself or lease it to downstream users.
The water and water rights are used for instream flows on North Boulder Creek beginning below the
city’s Silver Lake Pipeline diversion, near 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 Barker Reservoir for fulfillment of the CWCB junior 15 cfs instream flow right on Boulder Creek and
the CWCB 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. In addition to protecting the city’s
ability to provide water in the event of extended drought, this curtailment 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 water and water rights for municipal use if they are not needed to satisfy the
minimum streamflow requirements at the time.
3.4.9.2 | NORTHERN COLORADO WATER CONSERVANCY DISTRICT
The city joined NCWCD in 1953 and entered into a Water Delivery Contract for 12,700 units 125 .
The city water utility presently owns 21,015 units, which is the maximum number of municipal use units
Boulder is allowed to own based on rules set by NCWCD. There are 310,000 units total in the CBT
Project. A “unit” of CBT reflects a water user contract issued by NCWCD that provides delivery of an
amount of water based on the annual allotment set by the NCWCD board. A 100 percent quota
provides one acre-foot of water for each unit for that year. The historical average for the annual
quota is about 70 percent or 0.7 acre-foot per unit.
The amount of the annual assessment for each unit varies based on the terms contained in water user
contracts. The CBT units that were issued prior to 1959, including the city’s original CBT units, are
“fixed rate” units with an annual assessment amount that does not vary. Units issued to water users
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after 1959, including the city’s other CBT units, are “open-rated” units with annual assessment rates
that can be raised by the NCWCD board every year. In 1959, the NCWCD board had reviewed the
CBT Project finances and determined that NCWCD would not have enough revenues toward the end
of its forty-year repayment period to pay off its obligation to the United States (see section 3.2.2.9).
They instituted a new rule providing that assessment rates in newly-issued or modified water user
contracts would be variable and could be increased as needed to pay for project expenses.
Whenever a CBT unit is transferred from one water user to another or the original water user contract
is modified in any way, the unit is converted to an open-rated unit 126 .
The assessment for fixed rate units is set at $1.50. Boulder and all other water users on the southern
end of the CBT system pay an additional assessment of $0.50 per unit delivered from Boulder
Reservoir. The Boulder Reservoir delivery charge is assessed to pay for construction of the southern
delivery system components of the project that were not included in the original base project cost of
the 1938 agreement between NCWCD and the United States. Therefore, Boulder pays $2.00 per
unit for its 12,700 original CBT units. Boulder has 8,085 open-rated Class B (municipal use) units. The
assessment for these units in 2007 was $23.30 per unit. The city’s water utility also has 30 Section
131 units (general contracts that are renewed annually) for which it was assessed $24.10 per unit in
2007.
City use of CBT water is subject to operating rules of NCWCD. CBT water must be used within the
boundaries of the district and, unlike other trans-basin water, may only be used one time by the unit
owner. Water may be leased to anyone within the NCWCD boundaries.
CBT system storage space (over 720,000 AF) is operated by NCWCD. Boulder does not own any of
this reservoir storage, but has access to the storage benefits through ownership of units in the CBT
Project. Boulder can call for delivery of its CBT water up to the limits of the annual quota set for CBT
units by the NCWCD Board in any year. Delivery of the full quota amount can be made to Boulder at
any point within the CBT system, including from Carter Lake. Boulder’s share of water from the Windy
Gap Project is also delivered through the CBT system facilities.
Since joining the NCWCD in 1953, the city has signed several operating agreements with NCWCD
concerning Boulder Reservoir. Boulder owns an amount of storage space within Boulder Reservoir that
varies by season under a contract between the city and NCWCD. Ownership of Boulder Reservoir is
within the city’s water utility enterprise fund, and the recreational facilities are operated by Boulder’s
Parks and Recreation Department. The reservoir storage space is owned by NCWCD for the benefit
of CBT water users. Boulder’s storage space is divided into long-term storage for drought protection
and short-term seasonal storage. The long-term storage pool carries over from year to year. The
short-term storage space becomes available to the city in the winter season when the Boulder Feeder
Canal is off. This storage is presently used to feed the Boulder Reservoir WTF throughout the winter.
The Boulder/NCWCD 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 Boulder. The reservoir was built at Boulder’s
expense and NCWCD repaid one-third of the construction cost to Boulder over a period of forty
years. The 1953 annexation agreement provided for Boulder’s annexation into the NCWCD and
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specifies operating conditions for Boulder Reservoir that were modified in the March 14, 1975
agreement. 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 127 .
Supplemental Agreement to 1953 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 enlarged to ensure flood control protection for downstream properties on Dry
Creek and to increase utility of the structure. The operating capacity available to NCWCD from
May 1 – Oct 31 is 4,800 acre-feet. The portion of the reservoir allocated for flood control from May
1 – Oct 31 is 7,000 acre-feet. The portion of the reservoir allocated for Boulder’s long-term storage
is 1,000 acre-feet. An outlet canal and appurtenant structures were constructed to further increase
reservoir security and utility. The outlet canal is 3,000 feet in length extending from the termination of
the main outlet to the beginning of a siphon near Dry Creek and has a capacity of 200 cfs. Boulder
and NCWCD shared in the cost of the outlet canal features 128 .
Second Supplemental Agreement to 1953 Agreement – May 14, 1965
The 1965 agreement defined land area boundaries and identified which entity (the city or NCWCD)
has control of those lands and associated facilities. The definitions are reiterated in the March 14,
1975 agreement 129 .
Filter Plant Operating Agreement – May 9, 1969
In this agreement, Boulder agreed to finance and construct the infrastructure necessary to convey
water from Boulder Feeder Canal and from the reservoir to the water treatment facility. Boulder also
agreed to install measuring devices in the conveyance lines to produce a continuous record of flow to
the water treatment facility.
NCWCD agreed to 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 130 .
Obligations of NCWCD and City of Boulder – March 14, 1975
This agreement supercedes the 1953, 1954 and 1965 agreements. The intent and purpose of this
agreement is to provide the terms and conditions under which the respective rights and obligations of
NCWCD and the city to construction, operation, maintenance, modification, and management of the
reservoir and appurtenant facilities will be fulfilled.
In this agreement, the city agreed to design and construct a new spillway at its own expense.
NCWCD agreed to control, operate, maintain, and keep the reservoir in repair at its own cost in a
manner that benefits all its allottees. NCWCD also agreed to pay $371,561 to the city for the
perpetual use of a portion of the storage space in the reservoir, which is an amount equal to one-third
the original capital cost of the reservoir.
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Additionally, NCWCD assumed exclusive and sole control of the use, occupancy, operation and
maintenance of the following land areas that comprise portions of or are adjacent to Boulder
Reservoir:
Tract A: 60 foot buffer along the Boulder Feeder Canal inlet area;
Tract B: Parcel of land bordered on the east by the North-South County Road (63rd Street), on
the west by the North Dam of Boulder Reservoir, on the south by the access road immediately
south of Boulder Creek Supply Canal, and on the north by the access road immediately north
of Boulder Reservoir, and;
Tract C: Parcel of land within Boulder Reservoir that lies below the high water mark (or below
elevation 5,183 feet).
NCWCD assumed exclusive and sole control of the use, operation, and maintenance of the following
structures and facilities that are appurtenances of Boulder Reservoir:
chute structure at the terminus of Boulder Feeder Canal;
North 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
previously in this list and on, over, or across lands described in Tracts A and B, and;
fences, gates, cattle guards, drainage structures, or other facilities necessary and convenient
to NCWCD in the discharge of it responsibilities and which are or may be located on, over, or
adjacent to the facilities described previously in this list.
The city assumed exclusive and sole control of the use, occupancy, operation and maintenance of all
lands owned by the city that comprise portions of or are adjacent to Boulder Reservoir except Tracts
A, B and C, as listed above.
The city assumed exclusive and sole control of the installation, use, operation, and maintenance of the
following facilities:
all buildings and structures that are located on the lands owned by the city;
all roads, fences, gates, cattle guards, drainage structures, parking areas, 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, and;
the turnout installed by the city in the inlet portion of Boulder Creek Supply Canal and the
pipeline from turnout to the filter plant.
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Vehicular access by the general public on all NCWCD maintenance and access roads is not
permitted. However, public pedestrian traffic over the North Dam is allowed. The city may utilize the
land in Tract C below elevation 5,183 feet for municipal, recreational or other water supply
purposes. All recreational use at the reservoir is subordinate to the primary use of the reservoir for
water supply purposes.
The city retains the right to enlarge the capacity of Boulder Reservoir at its own cost and such
additional capacity will be operated by NCWCD 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. Three hundred acre-feet of capacity below
the invert of the auxiliary outlet (elevation 5,153.5 feet) is unavailable for use by either party. One
thousand acre-feet of capacity between the invert of the auxiliary outlet and the main outlet
(elevation 5,159 feet) is available to the city for long-term storage. A capacity of 11,800 acre-feet
lies between the invert of the main outlet and the spillway crest (elevation 5,183 feet) and is
available for use by both the city and NCWCD. The amount allocated for use by each party varies
by season.
NCWCD agreed to deliver the city’s water either to the water treatment facility intake structures or
to Boulder Creek through the Boulder Supply Canal. The delivery of water is limited to 90 cfs when
necessary to prevent impairment of water delivery to other NCWCD allottees 131 .
Amended Agreement – August 10, 1979
In this agreement, the portion of the reservoir capacity allocated for flood retention was decreased
from 7,000 acre-feet to 3,900 acre-feet due to completion of a spillway hardening project 132 . The
State Engineer’s Office had acknowledged that the improvements would allow the spillway to
withstand a significant spill event during a major storm, so a smaller flood retention pool was
acceptable.
Agreement Regarding Left Hand Ditch Company – November 17, 1992
Left Hand Ditch Company (Left Hand) owns water rights on Left Hand Creek. In 1963, NCWCD
signed an agreement with Left Hand permitting Left Hand to divert water from Left 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 year. Water diverted by Left Hand into the Boulder Feeder Canal was accounted for as
being stored in Boulder Reservoir. NCWCD performs the official accounting for water stored in
Boulder Reservoir and, each year, NCWCD kept track of the difference in the amount of water
diverted into the Boulder Feeder Canal by Left Hand and the lesser amount of water delivered by
NCWCD 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 between the city and NCWCD did not allow NCWCD to grant use
of Boulder Reservoir storage space to other users.
In 1992, the city signed an agreement with NCWCD allowing the storage of Left Hand water in
Boulder Reservoir. Boulder consented to Left Hand’s diversion of water into the Boulder Feeder Canal
and storage of that water in any available space in Boulder Reservoir. In return, each year Boulder
receives 20 percent of the difference between the amount of water provided by Left Hand and the
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amount of water delivered to Left Hand by NCWCD. The “20 percent 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 133 .
Substitution Agreement – April 8, 1994
This agreement is tied to the city’s use of its shares of The Consolidated Lower Boulder Reservoir and
Ditch Company (Lower Boulder) water per Case No. 94CW284. The NCWCD has a contract to
deliver CBT water its allottees through the Lower Boulder and Coal Ridge ditch systems. NCWCD can
deliver the city’s pro-rata share of Lower Boulder water to its allottees in substitution for CBT water
that would otherwise be delivered from Boulder Reservoir. In return, that portion of water is available
to the city for use from Boulder Reservoir 134 .
3.4.9.3 | SILVER LAKE DITCH AND RESERVOIR COMPANY AGREEMENTS
The city of Boulder has contracts with the Silver Lake Ditch Company that make the city’s relationship
with this company different than with other ditch companies. The original 1906 deed and agreement
and the subsequent 1955 and 1965 agreements are described in more detail below.
Deed and Agreement – January 15, 1906
In January 1906, the city of Boulder purchased Silver Lake and Island Lake reservoirs for $34,000
from the Silver Lake Ditch Company, through its owner, James P. Maxwell. The 1906 Deed for the
transaction includes the sale to the city of the land surrounding the reservoirs in the Silver Lake
drainage basin 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 [Silver Lake Ditch Company]…” The Silver Lake Ditch Company reserved the
“…right and privilege of storing such a quantity of water as may be contained…” in a defined
portion of the storage space in the city’s reservoirs, not to exceed one fill each year, for use by the
company 135 . The city had use of the first fill of the remaining portion of the reservoir storage and the
use of any refill of the entire reservoir space that occurred in any year 136 .
An agreement between the city and the Silver Lake Ditch Company, entered into at the same time as
the deed, further defined each party’s rights and obligations. The 1906 Agreement states that
storage water delivered to the Silver Lake Ditch Company by the city was to be used for irrigation of
1,006 1/30 acres of land north of what was then Boulder’s city limit. Within this agreement, the city
and Silver Lake Ditch Company recognized the ”…possibility that a considerable portion of said
1,006 1/30 acres of land will become annexed…” to the city 137 . Through the 1906 Agreement with
the city, the Silver Lake Ditch Company agreed it would not enter into any additional water delivery
contracts with Silver Lake Ditch water users for delivery of water from Silver Lake and Island Lake
Reservoirs. At that time, the Silver Lake Ditch Company was a carrier ditch company, as compared to
the other common corporate form for ditch companies known as a mutual ditch company 138 . Carrier
ditch companies have a contractual relationship with water users for water delivery. When Silver
Lake Ditch Company was first formed, assets remained in company ownership and the contract water
users did not have any rights of ownership in the ditch or in the company’s water or water rights like
shareholders in a mutual ditch company do. Instead, water users entered into a contract with the
Silver Lake Ditch Company that allowed use of water owned by the company on a specific property.
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The contract water users were not entitled to sell their right to have water delivered for use on their
property to any other water user for use on other property.
The city would initially deliver to the company an amount equal to the volume of water stored
between certain elevation planes in Silver Lake and Island Lake Reservoirs. The 1906 Agreement
provided that, as the Silver Lake Ditch Company’s obligation to deliver water under existing contracts
with ditch users diminished due to abandonment of contract rights, nonpayment of assessments, or
other provision for water, the amount of storage water delivered to the Silver Lake Ditch Company
by the city would decrease by the amount of the expired contracts 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 no longer used by the Silver Lake Ditch
Company.
First Supplemental Agreement – 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 Silver Lake Ditch Company by the city
and allowed the city to deliver the storage water from any source 139 . Since this amendment to the
original agreement was made, the water for Silver Lake Ditch has primarily been delivered out of
Barker and Boulder Reservoirs.
The need for the 1955 Agreement was triggered for two reasons. The first reason was the Silver
Lake Ditch Company’s dissatisfaction with how water was being stored under the various water rights
for Silver Lake Reservoir. The second was the city’s concern that land irrigated by the Silver Lake
Ditch had decreased since 1906, but the city’s storage water delivery obligation had not decreased.
When the city had lowered the Silver Lake outlet pipe in 1928, the lower portion of the reservoir
became accessible. Therefore, when water was diverted by the city under the most senior Silver Lake
water right that had an appropriation date of 1887, it naturally began filling the reservoir from the
bottom up and occupied the space below the elevation of the two planes defined within the 1906
Agreement for storage of water to benefit the Silver Lake Ditch Company. The next water rights to
fill storage space in Silver Lake were the city’s 1906, 1928, and 1941 water rights. Therefore, water
that was actually placed in-between the two elevation planes defined in the 1906 Agreement was
derived from more junior water rights that might not yield in dry years, and the amount of water
delivered to Silver Lake Ditch could be reduced in dry years. The Silver Lake Ditch Company
contended that the city had not been legally allowed to make changes to the reservoir facilities
without company approval. The issues were resolved through agreement that Silver Lake Ditch
Company would be provided with an amount of storage water to be calculated according to a
formula based on acreage still being served by the ditch and up to an amount equal to what the city
was allowed by the state to divert under the 1887 Silver Lake and 1890 Island Lake water rights.
Both water rights were adjudicated in 1907 and are junior to all water rights adjudicated prior to
1907, even if those rights have a more junior appropriation date. It was agreed that the city could
deliver this water from any available source. Therefore, the Silver Lake Ditch Company was no longer
confined to deliveries of water that physically existed in a defined reserved storage space within the
two reservoirs 140 . The city gained a defined methodology for calculating how much water delivery
the Silver Lake Ditch Company was entitled to receive under the contract as irrigated acreage
decreased and gained the ability to select the source for the Silver Lake Ditch water deliveries from
any water available to the city.
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Under the 1955 agreement, the city was initially obligated to provide the Silver Lake Ditch Company
with a maximum of 800 acre-feet from any city source, which equaled two acre-feet of water for
every irrigated acre under the Silver Lake Ditch. The city’s delivery obligation would decrease over
time in the following manner:
1. If the area irrigated with water supplied by the Silver Lake Ditch Company exceeds or equals
400 acres, the city will deliver 800 acre-feet.
2. If the irrigated area is less than 400 acres, the 800 acre-feet will be reduced by an amount
equal to one and a half times the deficiency in acreage below 400 acres (i.e. for every acre
abandoned, the amount delivered is reduced by one and a half (1.5) acre-feet). Therefore,
for the last acre of land irrigated with Silver Lake Ditch Company water, 201 acre-feet of
water will be delivered.
In the event the city was 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 Silver Lake Ditch Company from the city’s water sources, then the
amount the city must deliver to the ditch is reduced to an amount equal to the city’s actual yield from
the two water rights 141 . Because of the seniority of the subject water rights as compared to other
storage water rights, this situation might only occur in drought years or in years when spring snowmelt
occurs so slowly that few storage rights come into priority. For example, in 2002, the city was unable
to divert any water under the 1890 right and was only able to divert 148 acre-feet under the 1887
right.
In this agreement, the Silver Lake Ditch Company agreed that it would not carry water in the Silver
Lake Ditch for any other person or entity if this water carriage would adversely affect the city’s
ability to transfer and exchange water from any source for the municipal water system, excluding
contracts entered into by the Silver Lake Ditch Company prior to 1954. Additionally, the Silver Lake
Ditch Company agreed that the city could make alterations to the Silver Lake or Island Lake reservoir
outlets and agreed to drop the company’s objections to the city’s previous outlet changes.
Second Supplemental Agreement – June 12, 1965
In 1963, the city concluded that the Silver Lake Ditch Company Board of Directors had been
approving the transfer of Silver Lake Ditch 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 142 . The irrigation of new land using the Silver Lake Ditch would violate the terms of the
previous agreements between the Silver Lake Ditch Company and the city because the ditch company
was prohibited from entering into any new water delivery contracts. After trying to resolve the issue
with the ditch company, the city asked the courts to stop the Silver Lake Ditch Company from
transferring water to new land 143 . The Silver Lake Ditch Water Users Association met, replaced the
old Board of Directors, appointed a new board, and signed the 1965 Agreement with the city 144 .
The 1965 Agreement identified specific parcels of land that had historically been irrigated with
water from the Silver Lake Ditch. From that point of identification on, only land associated with a
specific Map Number under the 1965 Agreement was allowed to be irrigated with the contract
water delivered under the previous agreements 145 . The 1965 Agreement specifies that this water
may not be transferred to other parcels of land.
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The 1965 agreement provided that the right of individual properties to receive deliveries of storage
water under the contractual obligation between the city and the Silver Lake Ditch 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 property;
2. failure by the water user to pay an assessment when the payment is 5 years overdue;
3. no use of water upon the individual property for a consecutive period of 7 years during which
no assessments have been paid for the most recent 2 years out of the 7 years; and
4. a gift or other assignment to the city by the property owner.
Each year, the Silver Lake Ditch Company is required to provide the city with a list of the individual
properties on which water was used during the previous year and a list of properties upon which an
assessment is in arrears. Included with such information are changes in ownership and any subdivision
or re-grouping of separate parcels to the extent reflected in the Silver Lake Ditch Company records.
In 2008, there were active contracts for water delivery to 258 acres under the Silver Lake Ditch.
3.4.9.4 | BOULDER AND WHITEROCK DITCH AND RESERVOIR COMPANY AGREEMENT
The city and the Boulder and Whiterock Ditch and Reservoir Company (Boulder and Whiterock) have
an agreement for an “internal exchange.” When the internal exchange is operating, Boulder and
Whiterock diverts less water than it is entitled to take at its Boulder Creek diversion structure and the
city increases its diversions at its upper Boulder Creek intakes by an equal amount. The city then pays
the ditch company back by delivering an equal amount of the city’s CBT water supplies directly into
the Boulder and Whiterock Ditch from a channel connecting Boulder Reservoir and the ditch. The city’s
right to operate the internal exchange is based on an agreement with Boulder and Whiterock 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 awarded the city a right to exchange 250 cfs with an
appropriation date of 1954. The court also recognized that Boulder and Whiterock had a more
senior exchange right, dated 1926, but the court limited the Boulder and Whiterock exchange to its
historical maximum rate and volume of 100 cfs and 4,620 acre-feet annually vii . After the city filed an
appeal with the Colorado Supreme Court in Case No. 80SA102, the parties entered into an
agreement that allowed for the internal exchange and allowed the CBT water owed to Boulder and
Whiterock to be stored in Boulder Reservoir during the irrigation season. This agreement came about
because of the limitation on the Boulder and Whiterock exchange and the ditch company’s desire to
take advantage of the city’s storage space in Boulder Reservoir. For the city, the agreement was
appealing because of the potential advantage of reducing the Boulder and Whiterock exchange
needs even further. The relevant portions of the stipulated agreement were incorporated in the
amended decree entered in 1982 in Case No. W-7852-74 146 .
vii Boulder and Whiterock’s exchange limitation is not in the original decree for Boulder’s Boulder Creek exchange entered in 1980 by
the water court. A limitation on the amount of the Boulder and Whiterock exchange that is senior to Boulder’s exchange was put in the
amended decree entered in 1982 as a result of the stipulation in Case No. 80SA102, which was an appeal to the Supreme Court of
the original 1980 decree.
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3.4.9.5 | FARMERS’ DITCH COMPANY FOREIGN WATER CARRIAGE AGREEMENT
The city entered into an agreement with the Farmers’ Ditch Company 147 , dated May 2, 1967, that
allows the city to use any available excess capacity in the Farmers’ Ditch to carry foreign water
(water not attributable to the Farmers’ Ditch Company water rights) owned by the city. Therefore, the
city is allowed to divert any appropriately-decreed water it might own into the Farmers’ Ditch near
the mouth of Boulder Canyon and carry that water to Boulder Reservoir at times when the full
capacity of the ditch is not needed to carry water to Farmers’ Ditch Company shareholders. The city
pays one-fifth of the salary of the Farmers’ Ditch Company superintendent each year whether or not
any foreign water is carried and pays an additional amount for foreign water carriage that actually
occurs based on a formula contained in the agreement.
3.4.9.6 | NORTH BOULDER FARMER’S DITCH COMPANY AGREEMENT
Utilities purchased 656.2 shares in the North Boulder Farmer’s Ditch Company and sought to change
the use of those shares to include municipal use. The ditch company opposed the change of use
because the company believed transferring water out of the ditch would negatively affect the long-
term viability of the ditch. In an agreement dated November 30, 1993, the city agreed to not take
delivery of 96 shares of its stock when the company’s June 1, 1863 water right is out of priority.
(There is another water right associated with the ditch company dated June 1, 1862). Instead, the city
will leave the water associated with the shares in the ditch for the general benefit of the company
shareholders. The city may use this 1862 water in its municipal system at times the city determines is
necessary, such as in a drought or emergency. When the 1863 right is out of priority, the city can to
take delivery of the 1862 water attributable to the remaining 560.2 shares of stock for municipal
uses in or through the ditch.
Whenever the company’s June 1, 1863 water right is in priority, Boulder may take delivery of water
associated with all its shares at any decreed point or for any decreed use 148 .
The water utility entered into an agreement with the Parks and Recreation Department to allocate use
of the 656.2 North Boulder Farmers shares at Valmont City Park for irrigation 149 .
3.4.9.7 | CARIBOU RANCH AGREEMENTS
Caribou Ranch is located north of Nederland adjacent to the city’s Lakewood Reservoir property.
Through a complex series of agreements in 1996 (known as Caribou 1) and in 2001 (known as
Caribou 2), the city and Boulder County jointly purchased 2,181 acres of Caribou Ranch and
associated water rights from James Guercio, owner of Caribou Ranch viii . The city and Boulder County
each had separate agreements with Guercio. An agreement was also entered into between the city
and Boulder County in 1996, with revisions in 2001, to address financing of the acquisition, transfer
of ownership interests and other issues. A subsequent amendment to the city/ Guercio agreement was
made in 2004 to clarify provisions of the earlier agreements. The city, operating through the water
utility enterprise fund, used a portion of the revenue from the 1991 sale of 43 of Boulder’s 80 Windy
Gap units to the city of Broomfield to fund the Caribou Ranch purchase and was reimbursed for much
of the cost by Boulder County over a period of years 150 .
viii The series of agreements that accompanied these purchases can be found in the Appendices.
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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 Silver Lake Pipeline would be reconstructed. In addition,
the city desired to protect the quantity and quality of the portion of the city’s water supply
emanating from Caribou Ranch and diverted directly into Lakewood Reservoir. Provisions mandating
the city’s right to be involved in any Boulder County management activities that might affect water
quality were included in the agreement. The agreements also accomplished several other property
trades such as a land trade made to clear up property boundaries adjacent to Lakewood Reservoir.
Through the Caribou 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 conservation easement over this parcel. The city gained title from Guercio to a few
parcels of land at Lakewood Reservoir necessary to bring property boundaries into alignment with
the location of city facilities. Boulder County obtained title to the remainder of the purchased
acreage with the city holding a conservation easement over that acreage (Figure 3-3).
The County also acquired some of the water rights used for irrigating the ranch. Guercio retained
ownership of about 1,159 acres of Caribou Ranch, water rights for irrigation of his retained acreage
and water rights for some ponds. In addition to the fee properties, the city and Boulder County
acquired 1,517 acres of conservation easement over the Caribou Ranch property retained by
Guercio. Moreover, the city acquired a perpetual easement across the portions 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 (2001) agreement included discussion of development of a parcel of
land owned by Guercio that was adjacent to Caribou Ranch. The property, known as Caribou City,
had received plat approval from Boulder County in the 1970’s for development of 115 residential
lots. Boulder County no longer believed that level of development was appropriate, and the city was
concerned 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 units
plus a fishing lodge and a non-commercial horse barn.
The city of Boulder Open Space and Mountain Parks Department (OSMP) also participated in the
complicated Caribou agreements by contributing some funds that were used to purchase 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 (owned by the city through the water utility enterprise fund) that would still allow the
city 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 in the watershed that feeds the city’s municipal water system.
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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 irrigation of certain meadow areas only.
Another five 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 ix .
The city acquired Guercio’s interests in water rights he had initiated to develop hydropower on North
Boulder Creek, Caribou Creek and on the city’s Silver Lake Pipeline. The hydropower rights had been
decreed in Case Nos. 81CW419 and 82CW444. The city did not want these competing hydropower
rights to interfere with its hydro generation activities and so gave notice to the Water Court of intent
to abandon these hydropower water rights in 1999. The court issued orders abandoning the water
rights in 2001 and 2007.
The city provided almost all of the initial 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 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 Caribou Ranch property, the city water utility has input to the property’s
management plan to ensure watershed and water quality protection 151 .
3.4.9.8 | TOWN OF NEDERLAND AGREEMENTS
Water Storage Agreement
The town of Nederland operates its municipal water system based on an augmentation plan,
approved by the water court in 1980, which includes various water rights, including a 5/8 share of
the Farmers Ditch Company 152 . Because Nederland must supply water year-round, yet owns some
water rights that only yield water in the spring and summer, Nederland must store some water to
replace its fall and winter water use. The decree provides that the water attributable to Nederland’s
5/8 share of Farmers Ditch Company may be stored in Barker Reservoir up to an annual maximum
amount of 39.6 acre-feet. At the time of the decree, Nederland had an agreement with PSCo (now
Xcel Energy) to use storage space in Barker Reservoir for augmentation water. Nederland’s
agreement was not binding on Boulder and was not transferred to Boulder at the time of the Barker
Reservoir system sale in 2001. Boulder did allow Nederland to use otherwise empty Barker Reservoir
storage space on an informal basis until a Water Storage Agreement between Boulder and
Nederland was signed in 2008.
The 2008 agreement allows Nederland to use the same amount of storage space in Barker Reservoir
that was available to it under its prior agreement with Xcel Energy 153 . Releases of this water are to
be made by Boulder in accordance with normal operating procedures of Boulder’s water system in a
manner that does not interfere with those operations. Boulder may satisfy the water delivery
obligations with any water that is available to Boulder. Nederland grants Boulder a first right of
refusal to purchase any Farmers Ditch water that Nederland chooses to sell or lease during the term
of the agreement. Under Nederland’s court decree, Nederland projected the amount of water that its
ix Documents related to these leases can be found in the Caribou Ranch documents in the Appendices.
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service area would consume through at least the year 2010. The decree requires Nederland in 2010,
or sooner, to return to water court for a review of its augmentation plan. If any modifications are
made to the decree that result in a need for additional water to be stored for augmentation
purposes, a new agreement with Boulder will be required for any additional storage. The Water
Storage Agreement will terminate in 2026 unless the agreement is extended or a new agreement is
negotiated.
Land and Utility Tap Exchange Agreement
The Town of Nederland owns land on the west side of Barker Reservoir, on which it operates a Teen
Center. Nederland approached Boulder about building a skate park adjacent to the Teen Center
that would extend onto a portion of land owned by Boulder. Boulder agreed to deed this portion of
land (approximately 4,386 square feet) to Nederland in exchange for Nederland granting three
water taps and three sewer taps to Boulder at no cost 154 . Boulder will use the taps at restroom
facilities around Barker Reservoir. One facility will be located along the west end of the reservoir
near existing water and sewer pipelines. Nederland will operate and maintain this facility. The other
two facilities will be located along Highway 119. Boulder will have the option to exercise its right for
taps for these two restroom facilities whenever Nederland extends water and sewer mains to within
200 feet of the facility sites. Boulder will pay for construction of the facilities and for construction of
connections to the water and sewer mains.
3.4.9.9 | XCEL ENERGY POWER PURCHASE AGREEMENTS
The city is not an electric utility and therefore, it sells all electricity generated at the eight
hydroelectric plants located on the city’s water system to Xcel Energy on a wholesale basis. The city
has a series of power purchase agreements with Xcel Energy that specify the terms and conditions
governing the sale of power from each facility. Most of the agreements pertain to individual facilities,
and one pertains to multiple facilities. Each agreement contains rates of payment for generation
capacity and actual generation (the latter being subject to annual 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 with PSCo, Xcel Energy’s predecessor. 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 155 . Specific requirements and details of the
individual agreements affect the operation of the individual hydroelectric plants as the city balances
goals of maximizing renewable energy generation and hydropower revenues while maintaining
electricity generation as a by-product of municipal water supply operation.
Revenue calculation for the hydros, except Boulder Canyon which has a fixed monthly capacity
payment, includes two components: capacity and energy. Capacity is the instantaneous rate at which
a hydro facility can generate electricity and is measured in kilowatts (kW). Energy is the work
available as the electricity is generated over time and is measured in kilowatt-hours (kWh). As an
analogy, capacity is like the speed a car can travel and generated electricity is like the number of
miles traveled by the car. The speed of a car is the instantaneous rate the car is traveling, for
example 60 miles per hour (mph), and the number of miles traveled is the work performed. A car
may have the capacity to move at 100 mph, but it only travels at the rate necessary to meet the trip
conditions. The speed of the car typically will vary throughout the trip, and over time a certain
number of miles will have been traveled.
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-50
The methodology for calculating capacity and energy payment is defined in the Xcel Energy tariff.
The tariff defines four categories of facilities, one through four, depending on maximum facility
output. Maxwell, Kohler, and Orodell Hydros are category two facilities and Betasso, Lakewood,
Silver Lake, and Sunshine Hydros are category three facilities. The methodology for calculation of
capacity payment is unique to each category.
The energy payment method is the same for both category two and three facilities. Energy payment
is the number of kilowatt-hours generated times the energy payment rate ($/kWh). The energy
payment rate, adjusted annually, is determined from the operating costs of Xcel Energy’s Pawnee I
Generating Plant during the previous year.
Contract terms differ between each of the city’s contracts as summarized below in Table 3-2. An
important contract term to note is the date by which the city is required to give notice of its desire to
renew the contract for each facility. This is particularly important for the Betasso/ Lakewood/ Silver
Lake Hydros contract because the capacity payment terms are so favorable to the city, and every
effort should be made to continue this contract on the same terms.
TABLE 3-2. SUMMARY OF FACILITY-SPECIFIC CONTRACT TERMS
Contract Term Maxwell Kohler Orodell Sunshine
Betasso/
Lakewood/
Silver Lake
Boulder
Canyon
Contract
Signing Date
March 11,
1985
August 12,
1986
July 27,
1987
December 1,
1986 March 14, 1984 April 21, 2000
Commercial
Operation Date
April 10,
1985
October 31,
1986
September
10, 1987
September
10, 1987**
December 17,
1987
See specifics
below
Contract Term
from Date of
Commercial
Operation
30 years 30 years 30 years 30 years 30 years See specifics
below
Summer
Seasonal Test
capacity (kW)
70 148 220 810
Betasso/
Lakewood=5531
Silver
Lake=3043
See specifics
below
Extend Contract
No Later Than
Date *
April 10,
2013
October 31,
2014
September
10, 2015
September
10, 2015**
December 17,
2015
August 31,
2009
Winter
Seasonal Test
capacity (kW)
70 148 220 200
Betasso/
Lakewood=
2715
Silver
Lake=2000
See specifics
below
Category IPPF
facility 2 2 2 3
3 w/special
contract
provisions
Not Applicable
Capacity Rate
($/kW-month) $20.11 $19.38 $17.84
On-Peak=
$10.41
Off-Peak=
$7.43
$17.84/$8.92 See specifics
below
2008 Energy
Rate $/kWh $0.01659 $0.01659 $0.01659 $0.01659 $0.01659 $0.01659
*IMPORTANT NOTE: City must notify Xcel Energy to keep same contract terms.
** This is also the date for the 75th Street Wastewater Treatment Facility Cogeneration Plant.
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-51
Maxwell Pump-Generation Facility
“Seller (city) may extend the agreement, by written notice to Buyer at least two years prior to
the expiration of the initial term, under the foregoing terms and conditions in accordance with
the methodology set forth in the Company (Xcel Energy) Tariff”156 . “Seller agrees that Buyer
has the right to file with the Commission (PUC) proposed revisions to the current Company
Tariff (which the Seller has the right to protest) and that this Agreement shall be deemed to
be modified to incorporate any revisions to the Company Tariff, whether resulting from
revisions proposed by Buyer or otherwise”157 .
In the event of a power shortage by Xcel Energy, at Xcel Energy’s request, the city shall
implement all reasonable steps to provide additional energy as requested, and, if necessary,
delay any scheduled maintenance periods.
The city must submit a schedule showing scheduled maintenance periods annually. Any
scheduled maintenance period may be rescheduled upon mutual agreement.
Annual trip test performed on the protective relay equipment and a full calibration test a
least once every three years.
Induction generator - Must operate within leading or lagging 90 percent power factor
City must buy all power necessary to operate facility from Xcel Energy.
Contract is subject to the jurisdiction and applicable regulations of the PUC.
Kohler Pump-Generation Facility
“Seller may extend the agreement, by written notice to Buyer at least two years prior to the
expiration of the initial term, under the foregoing terms and conditions in accordance with the
methodology set forth in the Company (Xcel Energy) Tariff. Seller will give Buyer earlier
notice of its intent to extend if reasonably feasible”158 . “Seller agrees that Buyer has the right
to file with the Commission (PUC) proposed revisions to the current Company Tariff (which the
Seller has the right to protest) and that this Agreement shall be deemed to be modified to
incorporate any revisions to the Company Tariff, whether resulting from revisions proposed by
Buyer or otherwise”159 .
In the event of a power shortage by Xcel Energy, at Xcel Energy’s request, the city shall
implement all reasonable steps to provide additional energy as requested, and, if necessary,
delay any scheduled maintenance periods.
The city must submit a schedule showing scheduled maintenance periods annually. Any
scheduled maintenance period may be rescheduled upon mutual agreement.
Annual trip test performed on the protective relay equipment and a full calibration test a
least once every three years.
Induction generator - Must operate at or within a 90 percent power factor
City must buy all power necessary to operate facility from Xcel Energy.
Contract is subject to the jurisdiction and applicable regulations of the PUC.
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-52
Orodell Hydroelectric Facility
“Seller may extend the agreement, by written notice to Buyer at least two years prior to the
expiration of the initial term, under the foregoing terms and conditions in accordance with the
methodology set forth in the Company [Xcel Energy] Tariff. Seller will give Buyer earlier
notice of its intent to extend if reasonably feasible to do so 160 … If the Seller intends to
contract with a buyer other than the one stated in this Agreement following the expiration of
the 30 year term, Buyer shall have the right to match the provisions of the proposed contract
with this third party…”161 . “Seller agrees that Buyer has the right to file with the Commission
(PUC) proposed revisions to the current Company Tariff (which the Seller has the right to
protest) and that this Agreement shall be deemed to be modified to incorporate any revisions
to the Company Tariff, whether resulting from revisions proposed by Buyer or otherwise”162 .
In the event of a power shortage by Xcel Energy, at Xcel Energy’s request, the city shall
implement all reasonable steps to provide additional energy as requested, and, if necessary,
delay any scheduled maintenance periods.
The city must submit a schedule showing scheduled maintenance periods annually. Any
scheduled maintenance period may be rescheduled upon mutual agreement.
Annual trip test performed on the protective relay equipment and a full calibration test a
least once every three years.
Induction generator - Must operate at or within a 90 percent power factor
City must buy all power necessary to operate facility from Xcel Energy.
Contract is subject to the jurisdiction and applicable regulations of the PUC.
Sunshine Hydroelectric Facility
“Seller may extend the agreement, by written notice to Buyer at least two years prior to the
expiration of the initial term, under the foregoing terms and conditions in accordance with the
methodology set forth in the Company (Xcel Energy) Tariff. Seller will give Buyer earlier
notice of its intent to extend if reasonably feasible. Buyer shall have first right of refusal to
purchase Metered Capacity Output and Metered Energy Output if Seller intends to contract
with a buyer other than the one stated in this Agreement after the initial 30 year period”163 .
In the event of a power shortage by Xcel Energy, at Xcel Energy’s request, the city shall
implement all reasonable steps to provide additional energy as requested, and, if necessary,
delay any scheduled maintenance periods.
The city must submit a schedule showing scheduled maintenance periods annually. Any
scheduled maintenance period may be rescheduled upon mutual agreement.
Annual trip test performed on the protective relay equipment and a full calibration test a
least once every three years. City must submit certified copy of test results to Xcel Energy.
Induction generator - Must operate at or within a 90 percent power factor
City must buy all power necessary to operate facility from Xcel Energy.
Contract is subject to the jurisdiction and applicable regulations of the PUC
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-53
Betasso, Lakewood, and Silver Lake Hydroelectric Facilities
In 1984, the city negotiated a power purchase agreement with PSCo that included all three proposed
facilities. Betasso Hydro was constructed in 1987, followed by Silver Lake Hydro in 1988 and
Lakewood Hydro in 2004.
Contract term - 30 years from date of Commercial Operation of first operational facility. The
city may, by written notice to Xcel Energy two years prior to the expiration of the initial term
and each additional term, extend the contract for additional terms, for additional periods of
five years. The city will use its best efforts to give Xcel Energy earlier notice of its intent to
extend.
Billing capacity is the coincident maximum one-hour metered capacity output during the
monthly billing period of all three facilities.
Metered energy output (kWh) and metered capacity (kW) output mean respectively that
electrical energy and capacity generated by the facility.
Capacity Factor is the total net energy produced in kWh divided by the produce of the billing
capacity and the hours lapsed between monthly meter readings.
The capacity rate of $17.84 will be paid on the highest one-hour billing capacity if the
combined capacity factor of the three facilities is 50 percent or greater for the monthly billing
period. If the three facilities operate at a capacity factor of less than 50 percent, the
capacity rate will be 50 percent ($8.92).
In the event of a power shortage by Xcel Energy, the city shall implement all reasonable steps
to provide additional energy as requested.
The city must submit a schedule showing scheduled maintenance periods annually. Any
scheduled maintenance period may be rescheduled upon mutual agreement.
Annual trip test performed on the protective relay equipment and a full calibration test a
least once every three years. City must submit certified copy of test results to Xcel Energy.
Synchronous generators - Must operate at a power factor equal to1.
City must buy all power necessary to operate facility from Xcel Energy.
Boulder Canyon Hydroelectric Facility
Contract commencement date - March 7, 2001.
The contract shall terminate August 31, 2009 subject to the early termination provisions.
Xcel Energy shall own and maintain the facilities necessary from Xcel Energy’s transmission
facilities from the contract defined interconnection point and the 115-25 kV distribution
facilities.
Facility capacity is 10 MW.
The energy payment rate is $35/MWh for the on-peak hours in the months of June, July,
August, and September and $18/MWh for the on-peak hours in all other months. During off-
peak hours year round, the energy rate shall be the Qualifying Facilities energy payment
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-54
rate that is filled annually with the CPUC. The 2008 energy payment rate is $0.01659 /
KWh.
No payment will be made for energy produced in excess of 87,840 MWh in any year.
Annual trip test performed on the protective relay equipment and a full calibration test a
least once every three years. City must submit certified copy of test results to Xcel Energy.
Synchronous Generator—must be capable of operating at power factor of 90 percent
leading or lagging.
Xcel Energy has metering, bus relay protection, transmission line relaying and communications
equipment associated with Xcel Energy’s facilities.
Annual trip test performed on the protective relay equipment and a full calibration test a
least once every three years. City must submit certified copy of test results to Xcel Energy.
3.4.9.10 | 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 164 . These species included the whooping crane, the interior least tern, the piping plover
and the pallid sturgeon. 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
permit. The United States Fish and Wildlife Service (USFWS) had issued the opinion that any
depletion of water flowing in the Platte 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.
Background
Controversy developed in the early 1990’s when several water system operators sought land use
authorizations from the USFS for portions of their water projects that were on USFS land. This group
included the city of Boulder, PSCo and several other northeastern Colorado cities. Boulder was
seeking authorization for an easement for the Lakewood Pipeline. PSCo had applied for a special
use permit for the Barker Gravity Line as it crosses U.S. Forest land. As a part of the USFS process,
the USFWS was consulted under Section 7 of the Endangered Species Act (ESA)165 .
In 1994, USFWS issued a biological opinion for the Boulder Canyon Hydroelectric Project, the
Lakewood Pipeline and for the facilities owned by the other cities 166 . The USFWS found that water
depletions from projects in Colorado caused deterioration of habitat for the endangered species
listed above on the Platte River in Nebraska. The USFWS opinion concluded that the water projects
caused “jeopardy” to the species and that the “reasonable and prudent alternative” to address the
jeopardy was to replace all water depletions to the South Platte River on a one-for-one basis at the
Colorado-Nebraska state line x .
x Under the “jeopardy” standard in Section 7 of the Endangered Species Act, water project owners undergoing an individual
consultation with the USFWS would be responsible for providing the water to fully offset their own project depletions to the Platte River
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-55
Water users in Colorado did not agree with the USFWS analysis that depletions to the South Platte
River were affecting the species and formed a group to address the issue. This group hired engineers
and scientists who provided information to the USFWS demonstrating that there was more water in
the river at the Colorado/Nebraska state line during most times of the year than there had been
historically. This increase in flow has occurred due to changes in return flows into the river from human
water use and due to imported water from the West Slope. USFWS agreed that the South Platte
River in eastern Colorado had historically been dry in late summer prior to pioneer settlement and
had run at very low levels during much of the rest of the year. However, USFWS scientists argued
that the target species had become adapted to the stream temperatures resulting from year round
streamflows with the new flow regime. They also contended that the species remained dependent on
the very large flushing flows in the springtime that had moved sediment down the river prior to the
construction of reservoirs. These seemingly contradictory positions resulted in a claim by USFWS of a
need for an annual flow regime for the Platte River in Nebraska that would have required reservoir
storage in the spring to be greatly curtailed and any remaining stored water to be released for the
benefit of the species in late summer.
After much debate over differing scientific opinions, several alterations in the USFWS theories, and
threats of lawsuits by some water users in the three states over what they deemed was “arbitrary
and capricious” decision-making by the USFWS, it was determined that the problem might be better
addressed in a comprehensive manner involving participation by the three state governments rather
than through requirements placed on individual water users. This approach could also allow for
adaptive management or changes in the recovery efforts made for the species based on evolving
science and measurement of species response to previous recovery efforts.
Therefore, 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 United States Department 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 (EIS), 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.
Description of the Recovery Program
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 can be
made as needed through adaptive management. During the first 13 years of the recovery program,
the goal is to reduce shortages to the USFWS target flows in the Platte River by 130,000 to 150,000
acre-feet per year and to provide 10,000 acres of land in central Nebraska for habitat.
Recovery program costs consist of cash and cash-equivalent contributions such as water supplies. Total
costs will be shared with a 50/50 split between the U.S. Department of the Interior and the states.
Colorado’s share of the costs is 20 percent of the total recovery program budget. The program is
basin in the same amount and timing with which they occur. In addition, land acquisition and river sedimentation supplementation could
be required of project owners needing federal authorizations. Meeting these requirements on an individual basis would be onerous, if
not impossible.
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-56
projected to cost $317 million. Colorado state government will provide part of Colorado’s share and
water users will provide the rest through the South Platte Water Related Activities Program
(SPWRAP) non-profit organization. The state of Colorado will also provide water to the program
through construction of the Tamarack Project (see below) and other groundwater recharge projects.
Wyoming and Nebraska will provide much more water than Colorado due to the much higher level of
natural flow in the North Platte River in Wyoming and the Platte River in Nebraska.
The state of Colorado is presently completing the development of a recharge project in eastern
Colorado, called the Tamarack Project. This project will generate accretions from groundwater
diversions 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
years of the recovery program, the state of Colorado and South Platte River water users will be
responsible for completing the Tamarack 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.
South Platte Water Related Activities Program (SPWRAP)
The 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
recharge credits, and providing cash for recovery program operations and research. Both the state of
Colorado and SPWRAP will have representation on the recovery program Governance Committee
and its advisory groups.
The city of Boulder was contacted by the USFWS and the USFS in early 2007 about a previous
biological opinion that had been issued to PSCo in 1994 for the Boulder Canyon Hydroelectric
Project. The USFWS 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 Barker
system, the city joined SPWRAP at this time to maintain the viability of the previously completed
biological opinion and all of its associated studies. The Biological Opinion can serve to meet the
Section 7 compliance requirements for the city resulting from the USFS land use authorization for the
Barker Gravity Line and the Federal Energy Regulatory Commission (FERC) re-licensing process for
the Boulder Canyon Hydroelectric Project.
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 ESA compliance for a
participant’s water project and avoids individual mitigation requirements as a result of an ESA
Section 7 consultation. Membership payments in SPWRAP for municipalities are 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 2008 was $71,000. Payments in future years
are likely to be similar 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 assessments
for all prior years when they join later due to any future ESA Section 7 consultations they may face.
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-57
The city may withdraw from participation in SPWRAP and the recovery program with written notice
to USFWS. However, if the city withdraws, the USFWS may initiate consultation on the operation of
all or part of the city’s municipal water supply system. Participation in the recovery program does not
constitute any admission by the city regarding the application of the ESA to the depletions of the
city’s municipal water system or the validity of the facts or analyses relied upon by the USFWS. It
also does not require the city to agree that the USFWS flow recommendations for the Platte River are
biologically or hydrologically necessary to recover the target species or meet the needs of
designated critical habitat in Nebraska. Therefore, the city retains all of it rights to object if
implementation of the recovery program were to fail.
3.4.9.11 | USFS LAKEWOOD PIPELINE EASEMENT AGREEMENT
The city’s current easement for Lakewood Pipeline on National Forest land was signed in 2001 167 . As
discussed in section 4.2.1.12, Lakewood Pipeline was reconstructed from 2002 to 2004, and portions
of the pipeline include manufacturing welds which do not meet the contract specifications. In addition,
there appear to be abnormalities in the internal cement mortar lining of the pipeline. On May 12,
2004, the USFS issued a 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 USFS……” The USFS desires to terminate the existing easement and
replace it with a new one which would require the city to carry additional liability insurance and
include provisions for suspension of the easement under certain circumstances.
The acquisition of the 2001 easement agreement was laborious. The need for an easement was first
raised in 1986 because the city wanted to replace the lower four miles of the pipeline due to water
quality and pipeline reliability concerns. At issue was the city’s assertion that the Act of July 26, 1866
entitled Boulder to maintain and protect rights for the construction of ditches or canals that had been
established, as provided by the doctrine of prior appropriation (see section 3.2.1 “History of
Colorado Water Development” for more information on the prior appropriations doctrine). The Act
states, “That whenever, by priority or possession, rights to the use of water for mining, agricultural,
manufacturing, or other purposes, have vested…the…owners of such vested rights shall be
maintained and protected in the same; and the right of way for the construction of ditches and canals
for the purposes aforesaid is hereby acknowledged and confirmed”168 . It was therefore the city’s
position that it has a legal right to maintain the pipeline over the land with an express easement
because it had an implied “prescriptive easement.” The USFS contended that the city had abandoned
any 1866 Act rights it may have had by implementing a few minor pipeline alignment variations
during pipeline reconstruction in the 1940s and 1950s. In addition, the USFS intended to require the
city to bypass significant quantities of water for the purpose of mitigating impacts to aquatic habitat
resulting from city water diversions. Both the city and USFS have sought to avoid litigation over the
validity and scope of this right of way. Therefore, the city agreed in 1994 to complete an
environmental impact statement for the establishment of an express easement. Ultimately, language
to address the 1866 right-of-way and instream flows was carefully negotiated with the USFS with
Congressman David Skaggs mediating.
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-58
Other terms of the 2001 easement agreement are:
annual payment of $3,314.28 based on the fair market value of the use rights until further
notice;
perpetual easement with 30-year review for as long as the land is used for water
conveyance in accordance with the terms and conditions of the agreement (instead of 20-year
revocable Special Use Permit);
instream flow parameters, including a limit on the average pipeline flow of 20 million gallons
per day from May 20 through June 20 in order to achieve minimum streamflow identified in
the CWCB Agreement;
conducting maintenance in accordance with a USFS approved O&M plan, to be updated and
revised every five years;
a minimum of $1,000,000 in liability insurance in the event of death or injury to one or more
individuals and $50,000 for property damage, and;
a provision that the easement preclude the city from asserting its 1866 Act rights but not allow
the USFS to dispute these rights. The provision also affirms that the easement does not change
the scope of the 1866 rights, to the degree that they existed prior to execution of the
easement.
The city rejected a proposed draft of the new easement in 2004 due to concerns over liability
provisions and vague easement suspension language. Staff and USFS representatives negotiated a
new draft agreement in February 2008 refining liability provisions and conditions for easement
suspension.
In a March 2008 letter to the Boulder City Manager, the USFS included revised liability provisions in
a proposal for a new easement based on successful negotiations with city and USFS staff. The liability
insurance for the new easement is increased from $1 million to $3.5 million for death or injury of one
or more individuals; however the difference in insurance premiums is minimal. Other important
additions to the 2008 easement include that the immediate suspension clause require a threat that is
both “imminent and dire;” that the potential for immediate suspension include consideration of “the
threat to public health and safety of the residents of the city of Boulder who are dependent upon the
pipeline for drinking water;” and clarification that the failure to maintain instream flows as required
by the easement would not justify invocation of the immediate suspension clause. In addition, the
annual payment to the USFS is adjusted to $460 per year and may be adjusted annually to
“…reflect more nearly the fair market value of the use…” of the land 169 .
At the July 2008 Water Resources Advisory Board meeting, the board raised concerns about third
party indemnification and strict liability but recommended in a motion that City Council approve the
revised 2008 Lakewood Pipeline agreement with the proviso that the approval reference the USFS’
“interpretation of the immediate suspension clause and liability provisions” in the easement and affirm
that the easement does not diminish the city’s rights under the Act of July 26, 1886. Council is next
scheduled to review the new terms of the easement in 2009.
City of Boulder Source Water Master Plan Volume 2 – Detailed Plan
Final - April 2009 Page 3-59
3.4.9.12 | FIRE DISTRICT COOPERATIVE AGREEMENTS
The city’s North and Middle Boulder Creek source water facilities are located west of Boulder in
unincorporated Boulder County. Water utility land and infrastructure are located within various Fire
Protection Districts, which are special taxation districts formed to provide emergency services outside
of cities and towns. The Fire Protection Districts support fire departments, most of which are volunteer-
based. Because the city is a tax-exempt municipality, the districts do not collect tax revenues for city
lands and facilities. Some city facilities (e.g., Betasso WTF and several hydroelectric facilities) involve
response dangers that are beyond the normal volunteer fire fighter familiarity. Therefore, the city has
entered into separate agreements with several Fire Protection Districts to ensure timely and
appropriate response to emergencies which could arise at its source water facilities.
Fire Protection Districts are required to provide response to all properties within their district
boundaries, regardless of whether those properties are taxable or tax-exempt. In the absence of a
mutual agreement with a tax-exempt property owner, it is common for districts to bill tax-exempt
property owners for the actual cost of response to those properties. A major incident such as a
wildland fire requiring a large and lengthy response could easily cost the city hundreds of thousands
of dollars. The city therefore prefers to enter into agreements with districts and attempts to base
payments on land and facility value, such that the districts receive payment approximately equivalent
to what they would receive were the properties taxed.
The city first provided for fire protection of the Silver Lake Municipal Watershed in 1916 by entering
into a cooperative agreement with the USFS for the purposes of conserving and protecting the city’s
water supply. In addition to providing for mutual aid in the suppression of forest fires, this agreement
placed partial responsibility on the USFS to patrol the area and monitor activities within the
watershed. It allowed the USFS to remove timber that could be removed without injury to the water
supply. This agreement became obsolete upon the city’s closure of the watershed to public access
during the 1920s. However, due to the large tracts of National Forest land surrounding the city’s
watershed, under current forest fire management structure, the USFS would no doubt participate in
any fire suppression efforts required within the city’s watershed property.
The Silver Lake Municipal Watershed, including dams, reservoirs and the Silver Lake residence is
located within the boundaries of the Indian Peaks Fire Protection District. Indian Peaks entered into an
agreement with the city in 2004 to provide watershed fire suppression and rescue services free of
charge for 20 years in exchange for the city selling 5 shares of the capital stock of the Left Hand
Ditch Company to the Town of Ward for $10.
The Sugar Loaf Fire Protection District encompasses the Betasso WTF, Betasso and Lakewood Hydros
and much of the Lakewood Pipeline. In 2002, the city entered into a 20-year agreement with Sugar
Loaf to provide the full range of fire protection and other services which are normally provided to
other properties to all city lands, facilities and employees, contractors, vehicles and equipment within
District boundaries. The agreement requires the water utility to pay Sugar Loaf Fire Protection District
$155,000 between 2002 and 2021 for these protections. The city also provided Sugar Loaf with
two fire hydrants installed on the Lakewood Pipeline within the District’s boundaries.
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Boulder Canyon Hydro, Orodell Hydro, various pipelines and water utility land are located within the
Four Mile Fire Protection District. In 2006, the city entered into a 10-year agreement with Four Mile
to provide the full range of fire protection and other services which are normally provided by the
District to all city lands, facilities and employees, contractors, vehicles and equipment within District
boundaries. The agreement requires the water utility to pay Four Mile Fire Protection District $30,000
between 2006 and 2015.
Kossler Reservoir and portions of the Barker system fall within the boundaries of the Rocky Mountain
Fire District (formerly Cherryvale Fire Protection District). While the water utility does not have a
formal agreement with Rocky Mountain Fire, the city facilitates the District’s use of Kossler Reservoir
as a fire suppression water supply by allowing Rocky Mountain to construct fire suppression water
supply infrastructure on its Kossler Reservoir property.
Lakewood Reservoir, Silver Lake Pipeline, Silver Lake Hydro, the Lakewood and Barker residences,
several North Boulder Creek diversions, portions of the Lakewood Pipeline and Barker Reservoir fall
within the boundaries of the Nederland Fire Protection District. The water utility has proposed but has
not finalized a formal agreement with Nederland for the protection of water utility lands and
facilities. The water utility provided Nederland with one fire hydrant on the Lakewood Pipeline within
the District boundaries.
The water utility works with the Boulder Fire Department Wildland Fire Division to provide fire
hazard mitigation for its wildland-urban interface properties. Projects have included removal of dead
trees and downed fuel at the Silver Lake Municipal Watershed and forest thinning efforts at the
Betasso WTF and on Boulder Canyon Hydro and Kossler Reservoir lands.
The Boulder Fire Department has mutual aid agreements with most Boulder County Fire Protection
Districts. These help to ensure that sufficient manpower will be available for fire suppression on water
utility lands outside the city limits.
3.4.10 | WATER AND DISTRICT COURT CASES
3.4.10.1 | DITCH COMPANY ISSUES
The city of Lafayette and the Base Line Land and Reservoir Company sued the Anderson Ditch
Company and the city of Boulder in 1996 and 1997 xi . There were two lawsuits. One focused on
Lafayette’s claimed acquisition of one-eighth of one percent interest in Anderson Ditch and
Lafayette’s associated claimed unlimited right to use unused capacity in Anderson Ditch to carry
Lafayette’s water other than its Anderson or Base Line water (foreign water). The other concerned
Base Line’s claim for reinstatement of its 1911 agreement for carriage of water in the Anderson
Ditch, which was terminated by Anderson in early 1997 because of Anderson’s belief that Base Line
had violated the agreement in 1996, and its claim that the Anderson Ditch capacity should be
increased to allow carriage of greater amounts of water to Baseline Reservoir. The initial lawsuit
involved Base Line and Anderson; however, the cities of Lafayette and Boulder, as well as all other
Anderson shareholders, were also parties to the case.
xi Two binders of information on the lawsuit and resulting settlement can be found in the Utilities library located in the Park Central
building.
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The Base Line case was decided in 1999. The court reinstated the 1911 Base Line agreement, but
found that the Anderson Ditch Company has no obligation to enlarge the capacity of the Anderson
Ditch for the Base Line Company 170 . Prior to trial in the Lafayette case, Lafayette and Boulder entered
into an Intergovernmental Agreement in 2001 that resulted in settlement of the Lafayette case. The
agreement provided for Boulder to move its wastewater effluent discharge to a new point several
hundred feet downstream of its then-current location near 75 Street and for Lafayette to construct a
new pipeline from Goose Haven Ponds to a diversion point on Boulder Creek above the new effluent
discharge. In return, Lafayette gave up all of its claims to an ownership interest in the Anderson Ditch
and any associated rights to use the ditch capacity to carry Lafayette’s water, other than its rights as
a Base Line shareholder for carriage of Base Line water under the 1911 Base Line agreement.
Boulder and Lafayette completed construction of the new facilities in 2003.
th
The dispute between Anderson Ditch and Base Line arose because in 1997, Anderson discovered that
during 1996, Base Line had run water through the Anderson Ditch at flow rates above the safe
carrying capacity set by Anderson and had also run water not diverted under Base Line’s water
rights. Anderson terminated its 1911 agreement with Base Line under the belief that Base Line’s
actions were in violation of that agreement.
Base Line and Lafayette’s major claims against Boulder were that Anderson is the alter ego of
Boulder, which is majority shareholder in Anderson, and that the Boulder’s use of the Anderson Ditch to
carry stormwater is unlawful. The city successfully defended against these claims, and therefore, the
city cannot be held directly liable for Anderson’s actions up to the time of the lawsuit and the city’s
use of Anderson Ditch to carry stormwater cannot be attacked by Base Line or Lafayette again.
Lafayette was denied its claim to use the Anderson Ditch to carry water owned by Lafayette other
than its Baseline Reservoir water.
Base Line’s claim that the 1911 agreement was unlawfully terminated was granted and the
agreement was reinstated. The court ordered the following concerning the issues of operational
control of the ditch and Anderson’s responsibilities for maintenance and capital improvement of the
ditch under the 1911 agreement:
Anderson does not have a duty under the 1911 agreement to maintain the Anderson Ditch at
25 cfs or any other specific capacity;
Anderson has the sole and exclusive discretion to set a reasonable and safe carrying capacity
for the ditch;
Anderson’s obligations to Base Line under the 1911 agreement to clean the Anderson Ditch is
generally limited to removing trash and debris and occasionally to removing sediment
accumulation, and;
Anderson has no obligation to enlarge the Anderson Ditch from its current maximum safe
carrying capacity of 15 cfs.
3.4.10.2 | SOUTH PLATTE IRRIGATION WELLS
Boulder is an objector in several cases filed in Water District 1 Water Court by irrigation well users
on the lower South Platte River for approval of augmentation plans. Many well users have operated
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for decades based on substitute supply plans approved annually by the State Engineer. Between
2003 and 2008, settlements were reached in many of the well user cases.
Several of these cases were filed by Central Colorado Water Conservancy District (Central).
Settlement was reached in 2005 in a case for the augmentation plan for one of Central’s two
subdistricts—the Groundwater Management Subdistrict. A scheduled May 2006 trial in the matter
involving the other Central Subdistrict—the Well Augmentation Subdistrict (WAS) - was postponed at
Central’s request on the condition, proposed by Central, that 440 Central WAS wells had to be
turned off due to the lack of an approved augmentation plan.
In June 2006, other agricultural water users in the area of the wells reported that some of the Central
WAS wells were still being operated despite the water court’s order implementing the shutdown
proposed by Central in exchange for postponement of the May 2006 trial. The State Engineer’s
Office investigated and later sent notice to several irrigators to stop well use and filed actions in
court against a few irrigators.
The re-scheduled Central WAS trial was held in February 2007 and the Water Court issued a
decree in 2008. Central has filed an appeal of the decree with the Colorado Supreme Court, which is
still pending.
Water augmentation plans allow junior water right owners to take water at times when they
otherwise would not be allowed to divert because it would take water away from senior water right
owners. Under an augmentation plan, the junior water user provides replacement water to senior
water users to substitute for the water taken by the junior user. The time delay between use of a well
and the resulting reductions in river flow that must be replaced can range from days to years
depending on distance of the well from the river. Water augmentation plans must be approved by
the Water Court.
Two groups of water users that hold water rights senior to the South Platte wells are impacted if the
well owners fail to pay back water owed:
thousands of downstream farmers in northeastern Colorado from Brighton to Fort Morgan and
beyond, and other lower South Platte River water users like the city of Sterling, and;
upstream users like Boulder and others who have to send water downstream due to calls for
water from senior water rights owners.
For many decades, South Platte irrigation wells pumped water under augmentation plans approved
by the State Engineer. Well owners had committed under the plans to offset any reduction in water
available to senior water rights owners when the delayed effect of previous well use reached the
river. However, the State Engineer had not been requiring the well users to make sufficient water
payments.
Central WAS wells had pumped for many years and had created a large deficit in river flows that
occurred years after the original pumping took place due to the distance of the wells from the river.
In 2006 and again in 2007, the South Platte River had a shortage of about 15,000 acre-feet of
water each year due to the delayed effect of Central WAS wells.
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In prior years when Central operated under substitute water supply plans, the State Engineer
directed that water that Boulder should have been legally entitled to keep had to be passed along
to more senior water rights owners downstream from Central WAS, even though Central WAS should
have been responsible for replacing this water to the river. In effect, Boulder’s water has been used
to pay the water debt of the Central WAS well owners. Central WAS did not have enough water
available to them to pay the part of the water debt that came due in 2006, 2007 or 2008.
The issue of the State Engineer’s authority to approve temporary substitute supply plans, particularly
those that operate year after year with no apparent intention to seek Water Court approval, has
been a matter of much discussion in recent years. In 2000, in a case in Water Division No. 2, Empire
Lodge vs. Moyer, the Water Court determined that Empire’s approved temporary substitute supply
plan was unlawful. The case was appealed to the Colorado Supreme Court.
Boulder challenged the State Engineer’s contention that the state legislature intended to create a
“parallel track” to the water court process that would allow the State Engineer to approve temporary
substitute supply plans and to do so over extended periods of time with no opportunity for other
water users to comment or assess the extent of their injury. In December 2001, the Supreme Court
ruled that the State Engineer has no statutory authority to approve temporary substitute supply plans
except for replacement of evaporation losses from unlined gravel pits. In 2002, the legislature
enacted substitute water supply plan statutes that gave the State Engineer authority to approve
temporary substitute supply plans in limited and narrowly-defined circumstances, including where an
application for approval of a plan for augmentation is pending in a water court case.
In response to the Supreme Court ruling, the State Engineer proposed Amended Rules and Regulations
for the issuance of substitute supply plans within the South Platte basin. The proposed rules appeared
to Boulder to continue to claim more authority for the State Engineer to approve these plans than was
allowed by statute and as had been found to exist by the Supreme Court. In July 2002, Boulder and
approximately 50 other water users filed protests with the Water Court to the State Engineer’s
proposed rules. In December 2002, the Water Court judge ruled that the proposed rules were not
within the State Engineer’s authority. The State appealed the ruling to the Supreme Court which
affirmed the Water Court ruling in 2003.
South Platte River well owners, led by Central, sought new legislation in 2003 that would extend the
State Engineer’s authority and would allow the well users to continue well pumping under substitute
supply plans without a requirement that the wells owners ever go to Water Court for approval of
permanent augmentation plans. Such legislation was introduced as Senate Bill 03-73. Many owners of
senior water rights in the South Platte River basin who are injured by the continued operation of the
wells under substitute supply plans lobbied against the legislation, including Boulder.
Following negotiations between senior water rights owners and junior well irrigators, a modified
version of the bill was approved that allowed wells to continue operating under annually-approved
temporary substitute supply plans for a period of three more years without filing an application in
water court for approval of a permanent augmentation plan. Because the requirements under this
new statute were very stringent, hundreds of applications for new augmentations plans were filed
before and shortly after December 2003 so that the well owners could apply for substitute supply
plan approval under the portion of the 2002 substitute water supply plan statute that allows State
Engineer approval of such plans during the time a water court application is pending.
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Central and other South Platte well users have continued to seek new legislation in almost every year
since 2003 that would ease requirements that they pay the full amount of the depletions to the river
that affect senior water rights. These efforts have been successfully opposed by senior water rights
owners. In 2007, the governor formed a task force to study the issue and propose legislation that
might assist the well owners without injuring senior water rights owners 171 . The task force
recommended several minor statutory changes, none of which were subsequently adopted by the
legislature. The task force also recommended review of water court procedures which is currently
being undertaken by the Supreme Court’s Water Court Reform Committee.
3.4.10.3 | CONTRACTS ASSOCIATED WITH WATER PURCHASES
From time to time, the city has entered into lease-back agreements or other arrangements with
entities from which it has purchased water shares. One example is an agreement with Lakeview
Village from whom the city acquired Lower Boulder water shares and agreed to lease instream flow
water 172 . A second example is an interruptible supply contract with Boulder Creek Farms from whom
the city purchased Lower Boulder water shares 173 .
3.5 | Operational Considerations for Water Management
The city’s water supply sources vary greatly from one year to the next due to the semi-arid climate of
the region. This creates a need to carefully balance use of the city’s available water sources to assure
that sufficient supplies will be available both during seasonal periods of low streamflow and during
extended drought periods.
Boulder’s water supply is dependent on streamflows in Boulder Creek and the Colorado River, both
of which exhibit a high degree of annual variability. Droughts in the Colorado River basin generally
coincide with droughts on Boulder Creek, but this is not always the case.
By design, the water system components work together to produce the total system yield. Some parts
of the system will be used more extensively than other parts in different years depending on the
hydrology of the particular year. For example, one of the city’s source watersheds may be
experiencing dry conditions while the others are not, or the city may have more carry-over storage in
one source basin than another. This means that a particular source that is part of the system can be
talked about in terms of its average contribution to total system yield over many years, but the yield
from any one source can vary widely from year to year, depending on the hydrologic conditions of a
year and its preceding years. Judicious management and flexibility in the selection of which city
water source to draw on at any given time is necessary to assure that the maximum yield can be
obtained from the city’s water rights.
On average over the course of several years, under the present level of water demands in the city,
approximately 35 percent of the city’s annual municipal water supply is diverted from the North
Boulder Creek basin, approximately 35 percent is diverted from the Middle Boulder Creek basin,
and approximately 30 percent is direct use of water from the CBT and Windy Gap projects and
from the Farmers Ditch through the Boulder Reservoir WTF. CBT and Windy Gap water can also be
used indirectly as an exchange source for some of the diversions from North Boulder and Middle
Boulder Creeks when the city’s native basin water rights would otherwise be out of priority. A portion
of the diversions from Middle and North 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
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transported from the western slope supports 50 percent of the city’s annual diversions on average
with the other 50 percent derived from use of native basin water rights. The Silver Lake Watershed
and Barker sources are fully used, considering the need to maintain sufficient storage reserves in the
upper reservoirs to protect against drought, but the city is believed to own enough water at Boulder
Reservoir to meet all of Boulder’s future needs. As Boulder grows, the percentage of direct use of
CBT, Windy Gap and Farmers Ditch water at Boulder Reservoir WTF will increase to about half of
the city’s supply.
3.5.1 | MANAGEMENT OF CITY WATER RIGHTS
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 tributaries of the Colorado River to
provide municipal water supply. These include direct flow rights, storage rights, exchange rights, and
contract water delivery rights.
The city’s water rights that are decreed for municipal use are held within the water utility enterprise
fund. Assets held within the enterprise fund are constrained in their use for the primary purpose of
providing municipal water supply. The city also owns water rights that are decreed for agricultural
use and are used for irrigation of open space and parks. These rights cannot be directed through the
water treatment facilities and are held as a general use asset within the general fund or as an asset
restricted for Open Space use.
Use under Boulder’s many water rights is defined and limited by the terms of each water decree.
These terms include limitations on types of use, diversion location, if and where water can be stored,
season of diversion, if reuse after the first municipal use is allowed, maximum flow rate for the
diversion, maximum storable amount, minimum instream flow levels and the all-important priority date
as compared to other water rights. Municipal use includes a broad variety of allowable uses such as
residential uses, commercial uses, manufacturing, parks irrigation, fire-fighting and filling swimming
pools, but most uses are limited to within the designated municipal treated water system service area.
Very few of Boulder’s water rights allow the water remaining after the city’s first use to be claimed
by the city for reuse or augmentation of other uses, either because the rights were originally decreed
for a one-time municipal use or were agricultural rights that were changed to municipal use prior to
the time that change decrees commonly provided for reuse. Some of the city’s municipally-decreed
water, such as CBT water or the city’s Lower Boulder Ditch water can be leased for agricultural use.
In order for the city to divert water at any of the various 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 provided from another source. The amount of
water the city derives from the water rights for each of its municipal water supply sources varies from
year to year based on several factors including calls placed by other water rights, hydrologic
conditions in each water basin, and storage levels in the city’s reservoirs. The city keeps a daily
record of the diversion amounts at each municipal water system diversion or storage location and
records the associated water right that allows the water to legally be taken 174 . These records are
then submitted to the State Engineer’s Office (SEO), which is responsible for administering all water
diversions and water rights in Colorado. Boulder’s water managers are in frequent contact with the
SEO water commissioner to determine how much water the city is allowed to take and at what
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location. Particularly during the irrigation season, there is daily coordination with the water
commissioner because the call on the river can be different everyday due to quickly changing
streamflow levels and water demands.
The city determines which of its in-priority water rights will be diverted at a particular time based on
several factors including current municipal water demand, reservoir storage levels, water quality,
volumetric diversion limits in decrees, treatment plant staffing and service status of facilities. 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. The city’s choice of which available water to use is also influenced by economics and
secondary benefits of the use.
Under normal operations at times of plentiful streamflow, the higher quality, more easily treated,
gravity-fed waters derived from North Boulder Creek, Silver Lake Watershed and Barker Reservoir
water rights are used preferentially to meet the water demands of the city to the extent that
necessary storage reserves are not reduced. The city retains a portion of its annual Boulder Creek
water yield within its upper reservoirs rather than using every drop possible of this water because
storage releases will be necessary during winter periods and droughts to maintain a continuous water
supply to Betasso WTF. Once a determination has been made that the maximum safe level for use of
Boulder Creek water sources has been reached, the balance of the water demand is met by Boulder
Reservoir sources. Betasso WTF very rarely shuts down for more than a few hours because the upper
pressure zones of the city’s treated water distribution network heavily rely on a continuous feed of
water from Betasso 175 .
3.5.2 | OPERATIONAL “SEASONS”
Although greatly simplified, the city can be considered to have four operational seasons for its raw
water supply system. Three of these seasons are “nested” within each other. First, municipal water
demand on a particular day will usually be met by using in-priority, direct flow water rights before
pulling water out of storage. All of the city’s water needs can often be met this way during spring
snowmelt periods and the early summer when streamflows at the city’s upper pipeline diversion points
are high. This “direct flow season” (when the city meets all its needs directly from streamflow with no
reservoir storage releases) usually runs from about mid-May to late July, although it varies greatly
from year to year depending on the amount of winter snowpack accumulation and how quickly
snowmelt occurs.
Second, most of the water in Boulder’s municipal reservoirs is placed in storage during the spring
runoff period when streamflows are usually high. The city’s high elevation Boulder Creek reservoirs
have a very short window to fill during a “reservoir fill season.” There may be only four to eight
weeks between the time high altitude snowmelt begins in the springtime and when senior rights lower
on the river, such as direct flow agricultural irrigation rights, call out the city’s storage rights.
The third season comes into play if storage rights are called out before reservoirs are full. In such a
case, the city can use its exchange rights to release water from Boulder and Baseline Reservoirs to
fulfill downstream calling rights and take additional water into the city’s upper reservoirs as long as
there is streamflow physically flowing into the reservoirs. Additional water can be taken directly into
the city’s pipelines in this manner as well. The “exchange season” may be limited to just a few weeks
during the reservoir fill season. In dry years or years when the snowpack melts so slowly that
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streamflows don’t reach high levels, the river call will remain senior. In these years, the exchange
season may comprise the entire reservoir fill season, and any water placed in reservoirs will be solely
due to exchanges.
Lastly, as streamflows at the city’s upper diversion points drop in the summer, there is insufficient
physical supply to meet all of the water demand using direct flow. Therefore, usually starting
sometime in July or August, the fourth season begins when the city supplements direct flow diversions
with reservoir releases. By mid-October, all of the city’s water rights derived from shares in irrigation
ditches that have been changed to municipal use are no longer allowed to divert. The city can
continue to make direct flow diversions under its original municipal water rights. By wintertime,
streamflow levels are so low that most of the city’s demand is met with storage water. The “reservoir
release season” lasts until the following spring. City reservoirs are not completely drained every year
in order to assure enough water supplies in dry years, which is a reality in this semi-arid climate.
Committing to water uses that would claim all water available in wet years would use up water that
should be stored, like a savings account, to sustain water needs in drought years.
Reducing water demand through water conservation efforts improves the ability to fill reservoirs in
the reservoir fill season and slows the decline in the reservoir release season, thereby improving the
city’s ability to weather droughts by maintaining storage reserves. However, in any given year, once
the city’s storage reservoirs are full, reductions in water demand during the direct flow season have
no benefit for sustainability of the city’s raw water supply. Savings from water conservation during
this period reduce the amount of water the city diverts to its municipal system, but the city cannot
store the savings for later use or assign the saved water to another use. The effect is that streamflow
levels below the city’s intakes increase when demand is reduced during the direct flow season, which
may be noticeable during low streamflow periods but during high streamflow periods, there is no
significant habitat benefit from a little more flow 176 . The additional streamflow will benefit
downstream water users.
3.5.3 | RESERVOIR MANAGEMENT
As discussed above, because much of the water available to the city can only be captured in May
and June during spring runoff from the melting of the winter snowpack, the city’s water system is
greatly dependent on reservoir storage. Much of the water stored in these reservoirs is used from late
summer through the following early spring period to supplement water available from direct flow
sources. The water levels in the reservoirs are the lowest in the spring, just before the mountain
snowmelt begins. Prior to 1994, all of Boulder’s mountain reservoirs operated on a “low-point”
administration basis for purposes of the SEO’s one-fill rule that limits storage rights to diversion of the
volumetric limit only once a year. In 1994, Boulder selected fixed starting dates for the “reservoir
year” for two of its reservoirs. The reservoir year start date affects the determination of which
storage water right may be exercised at a particular time. Fixed starting dates were selected for
Barker Reservoir and Silver Lake Reservoir as a result of the decree in Case No. 90CW193 (the
instream flow program case). The fixed starting dates for these two reservoirs can be and have been
adjusted to new dates occasionally in cooperation with the Water Commissioner. The remaining
reservoirs continue to operate based on low-point administration for purposes of the one-fill rule. The
new water year for these reservoirs begins when the water level in the reservoir reaches the low
point each year. This means that some water storage years will be shorter than others, but will
average 365 days over time.
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The reliable yield of a reservoir is the maximum demand that can be consistently and reliably met
year after year without jeopardizing the ability to provide the same level of supply in dry years.
Therefore, the reliable yield is less than the full capacity of the reservoir. If the reservoir is intended
to provide protection against the possibility of a multi-year drought, the reservoir contents must be
apportioned to provide water for use in successive drought years. For example, to prepare for a
potential three-year drought period, the drought reserve pool of a reservoir with very junior rights,
which will not yield during a drought, should not be drawn down by more than one-third of its
capacity (less expected evaporation and seepage) during the first drought year. Taking more water
than this out of the pool could jeopardize water availability in the third year of a multi-year drought
if it should occur. Boulder manages its reservoirs to achieve the adopted reliability criteria 177 through
conditions as severe as those found within the historic streamflow record for Boulder Creek as
extended back to the early 1500s using tree-ring records. This record contains several multi-year
drought periods 178 . In addition, due to the potentially severe jeopardy to human health if no water is
available for essential indoor needs such as drinking water and toilet flushing, Boulder maintains an
emergency drought reserve pool of no less than 3,000 acre-feet in upper reservoir (Barker and Silver
Lake watershed reservoirs) storage and 800 acre-feet in Boulder Reservoir to provide a year’s worth
of water for essential public health needs that will not be accessed except in a drought worse than
any planned for or in the historical record.
The city’s units in the CBT Project act as a storage reserve for the city’s system. The city owns enough
CBT units to equate to about 7.5 percent of the 720,000 acre-feet of storage space in the CBT
Project reservoirs 179 . CBT water is managed by the NCWCD Board of Directors as a supplemental
supply to native basin water. Each year the NCWCD board sets the amount of water, or the quota, to
be delivered to each CBT unit. High quotas are typically set when East Slope runoff is projected to be
below normal 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 normal storage levels 180 . Modeling of the CBT system has projected that it can
deliver a 100 percent quota through the first two years of a three-year drought period similar to
1954-1957, which is one of the worst multi-year drought periods in the documented streamflow
record, before having seventy percent available in the third drought year when a 100 percent quota
would otherwise be expected 181 . In practice, the quota in the severe drought year of 2002, which
was worse than 1954, was set at 70 percent due to low water levels in the CBT system reservoirs.
Recorded streamflows are not generally available prior to 1900, but tree-ring reconstructions have
shown that more severe droughts than in the 1950s occurred on several occasions in the preceding
centuries 182 .
The city operates its municipal water system with the goal of maximizing water yield from the Boulder
Creek watershed while maintaining enough carry-over storage that continuous water supply to
Betasso WTF is never jeopardized. In addition to the jeopardy to adequate water supplies that
empty upper reservoirs would cause for the entire city, the effects on the upper pressure zone (Zone
Three) of the treated water distribution network on the west side of Boulder would be even more
challenging. If no water is available for delivery into the upper side of the city’s distribution system
from Betasso, then Zone Three would need to be fed by pumping water up from Boulder Reservoir
WTF. Although Boulder Reservoir WTF is sized at 16 MGD to provide sufficient water to meet the
essential indoor water needs of the entire city under build-out conditions, this water has to travel
through two other pressure zones and a series of pumping stations to make it up into Zone Three.
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Upgrades to the capacity of these pumping stations are planned in the future, but they are not
presently capable of moving sufficient water supplies into Zone Three to meet essential needs. In
addition, if the water users within Zones One and Two do not cut back all water use to essential
indoor need levels, the water provided by Boulder Reservoir WTF will be depleted before reaching
Zone Three 183 . Therefore, the city’s emergency drought reserve supply of not less than 3,000 acre-
feet is maintained in the upper Boulder Creek reservoirs to assure that water deliveries can be made
to Betasso WTF even under the most extreme conditions.
In the years when the Silver Lake Watershed reservoirs and Barker Reservoir fill and spill, the city
can be relatively confident that it will have sufficient water available to the municipal system until the
next year’s spring snowmelt period and that the city will have less vulnerability to water shortage in
the event of drought. In drier years, the city cannot store much, if any, water under its junior storage
rights, such as the 1956 and 1966 Barker Reservoir storage rights, which are often called out of
priority. In this situation, the city often relies on the ability to exchange other water to fill its
reservoirs, particularly Barker, by early summer. Factors that affect when and if the reservoirs fill
include physical water supply and municipal water demand. Physical supply is determined by spring
and summer precipitation at high elevations, mountain snowpack throughout the winter, temperature in
the mountains, streamflow runoff pattern, water rights yields and river conditions that affect the
ability to exchange water released from Boulder Reservoir or Baseline Reservoir for increased
diversions at the upper reservoirs. Water demand is influenced by the weather within the service
area of the municipal water system. For example, if weather conditions are wet and cold, irrigation
water demand drops and more water can be stored or kept in storage.
3.5.4 | MANAGEMENT OF EXCHANGES
Some of the city’s most important water rights allow the city to divert water out of priority at its
upstream diversion points in the Boulder Creek basin and replace it with an equal amount of other
water released by the city at downstream locations through what is called an “exchange.” When
exchanging, the city trades water from Boulder Reservoir, Baseline Reservoir, or several ditches for
additional water at the city’s upper Boulder Creek intakes or reservoirs. In many years, most of the
water the city stores in Barker Reservoir has been exchanged with CBT water released from Boulder
Reservoir 184 .
Exchanges help to maintain the carry-over water levels in the city’s Boulder Creek reservoirs to
protect against major water shortages during drought periods. In addition, 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 retained for later use. The city could not meet
the established water system reliability criteria without use of the exchange rights.
Use of Boulder’s exchange water rights is necessary in some years when the city’s native basin water
rights are called out of priority by more senior water rights from lower on Boulder Creek or from the
South Platte River. Only water rights calls coming from a point below the discharge point of the
exchange source can be satisfied by exchange. Senior calls occurring above this point on the river
must be answered by allowing water to pass by the city’s storage reservoirs and pipeline diversion
points. Therefore, the exchange mechanism can rarely be used outside of the higher flow periods on
the creek and is 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.
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The city has used an exchange water right since 1954, which allows exchange of up to 250 cfs from
Boulder and Baseline Reservoirs up to its diversion points on upper Boulder Creek 185 . A limitation to
the city’s 1954 exchange right is the physical space available in the Boulder Creek Supply Canal,
which carries water from Boulder Reservoir to Boulder Creek. Under the city’s contract with the
NCWCD, the city has a guaranteed right to preferential use of up to 90 cfs of the canal’s 200 cfs
capacity for its exchange 186 . It may use more than 90 cfs only if it is not needed for deliveries of CBT
water to others. Thus, including the city’s 50 cfs exchange right out of Baseline Reservoir, the city’s
total exchange capability under its 1954 right can be limited to 140 cfs at certain times.
The city can also exchange against the Boulder and Whiterock Ditch and Reservoir Company
diversions through an “internal exchange” (see section 3.4.9.4 for more information on this exchange).
Portions of the city’s Baseline Reservoir, North Boulder Farmers Ditch, and Lower Boulder Ditch water
are decreed as sources of exchange water and can only be used for municipal water supply
purposes through exchange since their diversion points are located downstream of the city’s water
treatment facilities. 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 (see section 4.3.1.3 “Exchange
Rights” for more information on Boulder’s exchange rights).
The city’s ability to use its exchange rights at any given time is limited by the minimum flow between
the city’s upstream “exchange-to” points (e.g. Barker Reservoir) and the city’s downstream
“exchange-from” points (e.g. the Boulder Creek Supply Canal outlet to Boulder Creek), which is
known as the “exchange potential.” This is because the city cannot operate its exchange in a manner
that would injure water rights that divert between the city’s upstream “exchange-to” points and
downstream “exchange-from” points. Also, even though the city’s exchange rights are senior to the
CWCB instream flow rights on Boulder Creek, it has been the city’s operating policy to not operate its
exchanges in a manner that would cause instream flows on Boulder Creek between Orodell and 75th
Street to drop below 15 cfs, which is the amount of the CWCB instream flow right in this stream
reach. In average to moderately dry years, the exchange potential is relatively high and the city’s
upper reservoirs are likely to completely fill. In more serious drought years, the exchange potential is
low, either because there is little streamflow above Barker or Silver Lake or most of that supply is
needed to satisfy senior water rights located on Boulder Creek between the exchange points. In this
situation, the city has difficulty filling its upper reservoirs.
In years when the ability to exchange water to fill the city’s upper reservoirs is limited, the ability to
exchange water from Boulder Reservoir to meet the city’s obligation to provide water to Silver Lake
Ditch is also limited 187 . Therefore, the city must deliver water to Silver Lake Ditch by releasing stored
water from Barker Reservoir. This increases the risk that the city will face shortages if drought
conditions were to continue.
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 or pumping system.
The increase in water available to the city’s upper water system also increases hydropower
generation. Water treatment costs are 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 city by gravity instead of by
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pumping, as is required for Boulder Reservoir WTF water. This both saves money and reduces
greenhouse gas emissions associated with the electricity for the pumps.
3.5.5 | INSTREAM FLOW EFFECTS ON MANAGEMENT OF CITY WATER SUPPLIES
The city donated use of some water rights to the CWCB for instream flows in Boulder Creek and its
tributaries. A condition of the new decree resulting from this donation was that Boulder had to limit its
municipal use of these rights to times when they are not being used for instream flow. To replace this
deficit in the water supply, Boulder treats more water at the Boulder Reservoir WTF. However, it costs
more to treat and deliver water from Boulder Reservoir WTF than it does from Betasso WTF. The
operational costs of the municipal water supply system have increased in order to support the
instream flow program. (See section 4.3.2.3 “Municipal Use of Instream Flow Water” for more
information).
3.5.6 | MANAGEMENT OF HYDRO OPERATIONS
The city has developed much of the environmentally and economically feasible hydroelectric
generation potential in its raw and treated water delivery system. This potential exists because of
large changes in elevation between the city’s diversion points and delivery points for its municipal
water pipelines. The city’s eight hydroelectric generators have a combined rated capacity of 20.1
megawatt-hours (MWh) and produce electricity with minimal environmental impact since the water
supply infrastructure is already in place.
The city’s Silver Lake Watershed and Middle Boulder Creek municipal water deliveries generate
hydroelectricity at the Silver Lake, Lakewood and Betasso Hydroelectric Plants above the Betasso
WTF. After the water is treated, it generates additional electricity at four small hydroelectric plants
on the treated water system below Betasso WTF. These turbine-generators were installed adjacent to
pressure reducing valves that are necessary for proper water supply operations, but that waste this
source of energy. Electricity is also generated from water returned to Boulder Creek at Boulder
Canyon Hydro. The generation capacity for each plant depends on available flow, turbine flow limits,
gross head, head loss and equipment efficiency. Available flow is set by the demand for municipal
water supply in Boulder. Much of the generation potential in the Boulder water system results from
high municipal water demand during the summer months.
The hydro plants generate about 45 million kilowatt-hours (kWh) of electricity a year that is sold to
Xcel Energy for about $2 million per year. Each year, the hydro plant generation offsets the need to
burn about 20,500 tons of coal and provides sufficient power to serve about 7,500 homes. Since the
first hydro plant went into service in 1985, 426,240,788 total kWh have been generated that
produced $20,242,118 of revenue for the water utility as shown in Figure 3-4 and displaced the
need to burn 213,332 tons of coal 188 .
Except for Boulder Canyon Hydro and on rare occasions with Silver Lake Hydro, the same amount of
water would be conveyed through the pipelines to meet municipal demand with or without
hydropower generation facilities. Therefore, water flowing through the city’s hydroelectric facilities is
mostly unavailable for other non-municipal uses because it is subsequently delivered for municipal
supply.