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HomeMy WebLinkAbout4 - Developement of the Long Term Drought Response Plan CITY OF BOULDER WATER RESOURCES ADVISORY BOARD MEETING DATE: August 19, 2002 SUBJECT: Discussion of the development of a Drought Response Plan and scoping of elements and topics to be addressed in the plan including process for completion of the plan and receipt of public input on water conservation measures REQUESTING DEPARTMENT: Public Works Department: Robert E. Williams, Director of Public Works for Utilities Carol Ellinghouse, Water Resources Coordinator BOARD ACTION REQUESTED: Discussion of the development of the Drought Response Plan FISCAL IMPACT: None at this time. PURPOSE The drought of 2002 is proving to be the worst single drought year in over 100 years. It is unknown if the drought will extend into next year. Based on analysis of extended hydrologic records, there have been many instances of multi-year droughts in the.Boulder Creek basin. On July 9, 2002, City Council discussed issues related to the city's water use restrictions this year and long term drought planning. Prior to that time, staff was preparing a Drought Response Plan. The plan would provide the city with options to follow in the event of a severe drought and guidelines for recognizing when a drought year might significantly impact the city's ability to deliver water. Given the experiences of the past few months, it will be necessary to alter some of the content of previous drafts of the Drought Response Plan to accommodate new knowledge gained and evaluate the sufficiency of the city's response to this year's drought. A process is proposed for completion of a Drought Response Plan that would incorporate opportunity for public comment on the structure of water use restrictions. WRAB AGENDA ITEM, Page 1 BACKGROUND On May 1, 2002, snowcourse readings indicated that this year's spring runoff from mountain snowmelt would be significantly below average. Therefore, the city's water supplies for the next year until the next spring runoff would be greatly reduced from the average. On May 8, 2002, the city requested that its citizens and water users follow a strong voluntary water conservation effort in response to the drought. By mid-May, it was evident that streamflows were even lower than predicted, and drought conditions were more severe than in any previous year within the historic record. After two weeks of voluntary water use restrictions, it was clear that voluntary efforts were not successful in reducing water consumption. On May 21, 2002, it was determined that mandatory water use restrictions would be required to assure that sufficient water supplies were available to meet the city's needs until the following spring snowmelt. On June 4, 2002, City Council adopted Ordinance No. 7215, by emergency to amend the City Code to set forth measures for water conservation implementation, including restrictions on water use. City Council also requested that an ordinance be presented at the next Council meeting concerning an increase in water rates as another means to achieve water conservation. On June 5, 2002, the "Regulations Concerning Water Conservation and Water Waste" were approved by the City Manager, and the city began active enforcement of water use restrictions. To date, Boulder's water customers have successfully met each week's water use target. At the July 9, 2002, meeting, City Council considered an ordinance to increase water rates. It was determined that a rate increase was not necessary at this time since the mandatory water restrictions in place were effective in reducing water use to the target levels. Council requested that a Drought Response Plan be completed to review drought planning issues and potential elements of future water conservation efforts during drought periods. WATER PLANNING Since Colorado has a semi-and climate, the need for management and planning for available water supplies is critical. Although surface water is a renewable resource, its quantity changes on an annual basis depending on a variety of factors. Given Boulder's location so near the continental divide, the city's water supplies are almost entirely dependent on mountain snowmelt. The mountain snowpack accumulates every winter and melts in the spring. Almost all of Boulder's water supplies for the entire year are captured in reservoirs during the spring snowmelt in May and June. A low winter snowpack in the mountains can lead to a shortage of water supplies for the next year. Droughts can take many forms. A drought can be severe for a single year with a return to average precipitation levels immediately afterward, or it can continue for several years. A long series of slightly below average years can gradually diminish available water supplies over a WRAB AGENDA ITEM, Page 2 i longer period of time. Based on hydrologic records for the Boulder Creek basin, several severely dry years can follow each other in succession once or twice each century (see Attachment A.) Water planning efforts are a means to deal with the certainty that there will be periods when available water supplies are limited. Water planning can include three elements as follows: 1. Water resource evaluation includes the analysis and forecast of snowpack, rainfall and streamflow to determine specific yields of water rights and quantities of available water. 2. Water supply management includes the construction, operation, and management of the infrastructure necessary to divert, store, deliver and treat water supplies. 3. Water demand management includes methods to control and reduce water use through public education, plumbing codes, landscape requirements, water use restrictions, and water rate structures. DROUGHT RESPONSE PLAN DEVELOPMENT Much of the information to support development of a drought plan has previously been developed through the Raw Water Master Plan, the Treated Water Master Plan, the Boulder Creek basin watershed model, Boulder Creek tree ring studies, and the Water Conservation Futures Study. A Drought Response Plan was in the process of being prepared prior to the 2002 drought. The preliminary information developed for this plan will need to be updated and revised to contain information developed as a result of this year's experiences. It is proposed that a Drought Response Plan will evaluate the following items: Water Resource Evaluation 1. Review current water rights and determine reliable water yields through droughts of varying severity including the 2002 drought and those of greater severity identified in tree ring studies. 2. Review the Instream Flow Program and use of local irrigation ditches to determine untreated water demands to be satisfied by the city. 3. Document historic municipal water demands and adjust as needed for future planning scenarios. 4. Determine if new water supplies are required to meet long-term community needs under various use scenarios. Water Supply Management 1. Evaluate previously adopted reliability criteria and level of public tolerance for supply interruptions in greater than 1-in-100 year droughts. 2. Evaluate the amount of system water loss as well as the effectiveness of current operation and maintenance activities at reducing losses to an acceptable minimum. WRAB AGENDA ITEM, Page 3 3. Optimize the balance between maximizing water supply availability, minimizing water quality threats to human health, minimizing water treatment costs, and maximizing hydropower generation revenue. Water Demand Mana ement 1. Review the current water rate structure to determine if the present 3-block, inverted rate structure most effectively meets the community's goals. Evaluate alternatives such as seasonal rates, penalty rates, surcharges, lower rates for interruptible customers and inside/outside city rate differentials. 2. Evaluate plumbing codes for their effectiveness in managing water demand including low flow fixture requirements and rebate programs for retrofits. 3. Establish priority of water use for implementing interruptions of service as between uses such as home indoor use, commercial use, and landscaping use. 4. Evaluate land use codes for effect of changes such as limitations on building or lot size. 5. Evaluate landscape requirements for houses, public areas, commercial areas and medians for effects of maximum turf area limits, xeriscape use, and irrigation system design. 6. Evaluate modifications needed for existing water use restrictions in the event of a multi-year drought. 7. Determine the effect of discouraging water-intensive uses or industries from connecting to the municipal system. STAFF RECOMMENDATION Staff recommends that a Drought Response Plan be completed prior to next spring. An outline for a draft Drought Response Plan will be available for the next WRAB meeting in September. Staff recommends that a public hearing be held at this next WRAB meeting to allow public comment on the issues to be considered in a Drought Response Plan and to provide scoping for the plan development. Following this meeting, two separate public meetings can be held in late September and early October. The comments from this public meetings can be incorporated into the plan development process and a final draft Drought Response Plan presented at the October WRAB meeting. Following WRAB acceptance of the plan, it can be presented to City Council. ACTION REQUESTED Provide input to staff on the scope of the Drought Response Plan and the process for its development. ATTACHMENTS Attachment A--Historic Boulder Creek Flow Based on Tree Ring Evidence WRAB AGENDA ITEM, Page 4 Hydrosphere Resource Consultants, Inc. August 13, 2002 Natural Flow, Boulder Creek Near Orodell 2002 Compared to Flows Reconstructed From Tree Ring Evidence 180,000 Flows for 1703-1987 based on tree ring reconstructions (Dr. Flows for 1988-2001 reconstructed from gage flows (Hydrosphere). Projected flow for 160,000 - Connie Woodhouse and Hydr_osphere). 2002 reconstructed from gage flows and City operation records, and adjusted upward to incorporate uncertainty inherent in tree ring data (Hydrosphere). Actual projected natural flow for 2002 is expected to be less than 29,000 AF 140,000- Projected Flow for 2002 120,000 Lowest year since 1703 Average (adjusted to be consistent based on tree ring evidence - Annual Flow - with tree ring data) = 29,600 A 73,700 AF 32,000 AF 100,000 - - - - - - a. m L 80,000 a 60,000- ~ F1i3 ~ y^ w r.. 40,000 u . 20,000 0 's) b '(P '\Na' .~'~p .~Q;> A'5 ,~6`b ,~C`b ~O`b ~'`~ry`b ~^~`b ~~rb ~5P ~p ~00rb ~0`b 0`b pu923 p p~0 9"p po'o`h '1b p~0rb pu'(p 4P 1 1 ,c6 N(>, N N 0 No, / CITY DEPARTMENT OF PUBLIC WORKS P.O. Box 791 OF 1739 Broadway BOULDER Boulder, Colorado 80306-0791 website: www.ci.boulder.co.us/publicworks AREA CODE 303 ADMINISTRATION July 20, 2002 INFORMATION J 441-3200 FAX 4414210 BUILDING MAINTENANCE Mr. Chips Barry FAX 441-4063 Denver Water Department BUILDING SERVICES 041-1668 1600 West 120i Avenue FAX 441 3241 FACILITIES Denver CO 80204-3412 ASSET MANAGEMENT M 441-4058 FAX 4414063 FLEET 54R37037 RE: Cloud Seeding Program FAX 4, 3-]157 DEVELOPMENT 6 INACTION BERVICES Dear Chips, ENVIRONMENTAL ENFORCEMENT 441 -3239 FAX 441.4070 Thank you for your July 2, 2002 letter exploring the possibility of regional FLOODPLAI MANAGEMENT participation in a cloud seeding program. I'd like to express my conditional interest 441-4232 FAX 441-3241 in participating in the cloud seeding program, depending upon what our literature RousR RENTAL LICENSING review might show concerning the environmental impacts of silver iodide on 441-3152 FAX 441-3241 surface water supplies and on the final locations of the cloud seeding target areas. INSPECTION SERVICES 4414088 FAX 441-40]0 LAND INFORMA ION . The areas that Denver Water are considering for the cloud seeding program do not MAPPING H RECORDS 210 entirely include the watersheds that supply Boulder's municipal supply. In terms of FAX °°14271 through its inclusion ZONING CODE water sulip1y> Boulder is more of a northeastern Colorado city ii ENFORCEMENT in the Northern Colorado Water Conservancy District (~NCWCD) than as Denver 441-3346 Y \l, FAX 44,-4070 metropolitan area. Therefore, I do not believe a cost distribution based on TRANSPOARRAPOIORTT population is an equitable plan for Boulder. However, Boulder may gain some FAX 440190 benefit from cloud seeding efforts in the Winter Park and Fraser River basin area GO BOULDER 441-3266 when storms cross the continental divide into the Boulder Creek watershed. FAX 441-4271 ENGINEERING Therefore, Boulder would consider a contribution of $3,000 toward a program FAX °444;- 266 targeted for the winter of 2002-2003. STREET MAINTENANCE 413-]162 FAX 413-7160 In addition, I am also trying to better understand any environmental impacts ENGINEERING concerning the use of silver iodide in cloud seeding efforts. While I am reviewing FAX "1-427166 literature on this topic, it would be helpful if Denver Water would: UTILITY BILLING 441-3260 a share any information or analysis it has related to this topic, FAX 441-4089 Y UTILITES MAINTq 3A7N E • request such information from your weather or cloud seeding consultants, and FAX 413-7163 WASTEWATER • let us know if there will be any testing and monitoring program associated with TMENT 75 HESTREET the cloud seeding activity for the winter of 2002-2003. 413-7340 FAX 413-73]3 WATER RESOURCES 441-3266 I appreciate your initiative in the effort to increase our region's precipitation. Please 441-4271 WATERFTREATMENT keep me informed as the program develops and let me know if Boulder's response 63SO STEET 413-7430 is satisfactory. FAX 530-113] WATERTREATMENT BETASSO 441-3245 Sincerely , FAX" 14474 WATER DUALITY ENVIRONMENTAL SERVICES S 114- W L. !X/ 1~/.~ ^^"V 63RD STREET - 413-7400 FAX 530-0137 Ned Williams WATER DUALITY ENVIRONMENTAL SERVICES S SH STREET Director of Public Works for Utilities 413-7350 FAX 413-7373