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Home My WebLink AboutCC 2026-04-28_09c Monthly Water Supply and Demand UpdateItem 9.c. MEMORANDUM TO: City Council FROM: Bill Robeson, Assistant City Manager/Director of Public Works BY: Shane Taylor, Utilities Manager SUBJECT: Monthly Water Supply and Demand Update DATE: April 28, 2026 RECOMMENDATION: Receive and file the Monthly Water Supply and Demand Update. IMPACT ON FINANCIAL AND PERSONNEL RESOURCES: Approximately two (2) hours of staff time are required to prepare the report. BACKGROUND: The City of Arroyo Grande’s water entitlements are calculated on a water year that begins April 1, 2026. The current water supply for water year 2026 -27 includes:  2,290 Acre Feet (AF) from Lopez Lake Reservoir/Lopez contract entitlement.  The current modeled safe yield is 357 AF of groundwater from the Santa Maria River Groundwater Basin, with an entitlement of 1,323 AF.  An additional 160 AF of groundwater is available from the Pismo formation from the existing City well system. In addition to the annual Lopez Lake Reservoir contract entitlement, the City will have 1,573 AF of stored Lopez water, which is unused entitlement from water year 2025 -26. There will be no surplus water available due to the downstream release made in water year 2025-26 of 5,290 AF, which is 1,090 AF above the contract amount. The total supply from Lopez Lake Reservoir for this water year is 3,863 AF. The predicted water use for the 2026-27 water year is 2,200 AF. In March 2026, the City’s water use was 159.1 AF. The overall per capita use was 93 gallons per day. The residential per capita use was 72 gallons per day. There has been a total of 15.6 inches of rain since July 2025 at the Corp Yard gauge. Page 27 of 209 Item 9.c. City Council Monthly Water Supply and Demand Update April 28, 2026 Page 2 ANALYSIS OF ISSUES: As of April 10, 2026, the USDA Drought Monitor rep orts San Luis Obispo County as normal. Lopez Lake is at 87.1% (43,124 AF). The deep well index for the First quarter of 2026 was completed on February 24, 2026. The index level was 12.28 feet above sea level, which is 4.78 feet above the threshold value. T he current deep well index is 1.74 feet higher than October 2025, and 0.04 feet higher than January 2025. On January 15, 2025, in response to a preliminary injunction issued by the United States District Court to the County of San Luis Obispo, Lopez Lake downstream release rate was in place until December 29, 2025. The 9th District Court of Appeals overturned the preliminary injunction and returned the water releases to the interim downstream release schedule. The current release rate on January 14, 2026, was 4.8 cubic feet per second (cfs) or 3.1 million gallons per day. A gradual decrease in the release process to former rates is necessary to monitor creek conditions. The current rate as of April 10, 2026, is 3.4 cfs or 2.2 million gallons per day. The City and all other Zone 3 contractors will continue to work with the County to assess and report on the impact on our water supply from Lopez Lake until the litigation is resolved. However, the significant costs of the ongoing litigation and future improvements will be shared by the ratepayers of the City and other Zone 3 member agencies. To keep the community informed of the current status of the litigation and the City’s water system, staff have developed a webpage where updates will be published. The we bpage can be accessed at www.arroyogrande.org/lopezlakelitigation. Council Goals Workplan In the current Council Goals workplan for Fiscal Year 2025 -27, under the Council Goal of “Achieve Water Resilience”, the Council has directed staff to Pursue 2026 State Water Ballot Measure, with the specific subtask to Seek Council approval placing a November Ballot Measure. On March 10, 2026, the Council provided direction to bring back final ballot language for consideration to place the item on the ballot for the November 2026 General Election. ALTERNATIVES: The following alternatives are provided for the Council’s consideration: 1. Receive and file the report, or 2. Provide other directions for staff. ADVANTAGES: The report provides the City Council and the public with the current and projected water supply and demand conditions. Page 28 of 209 Item 9.c. City Council Monthly Water Supply and Demand Update April 28, 2026 Page 3 ENVIRONMENTAL REVIEW: No environmental review is required for this item. PUBLIC NOTIFICATION AND COMMENTS: The Agenda was posted at City Hall and on the City’s website in accordance with Government Code Section 54954.2. ATTACHMENTS: 1. Monthly Operations Report for March 2026 2. Lopez Lake Reservoir Storage Projections 3. Previous Use Comparison 4. 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