HomeMy WebLinkAboutCC 2026-05-26_09i Water Supply and Demand UpdateItem 9.i.
MEMORANDUM
TO: City Council
FROM: Bill Robeson, Assistant City Manager/Director of Public Works
BY: Shane Taylor, Utilities Manager
Hailie Hix, Utilities Manager
SUBJECT: Quarterly Water Supply and Demand Update
DATE: May 26, 2026
RECOMMENDATION:
Receive and file the Quarterly 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.
In addition to the annual Lopez Lake Reservoir contract entitlement, the City will have
1567 AF of stored Lopez water, which is unused entitlement from water year 2025 -26.
There will be no surplus water available for purchase as was done in previous water years
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 3,857 AF. The predicted
water use for the 2026-27 water year is 2,200 AF.
In April 2026, the City’s water use was 192.7 AF. The overall per capita use was 116
gallons per day. The residential per capita use was 89 gallons per day. There has been
a total of 18.1 inches of rain since July 2025 at the Corp Yard gauge.
Page 165 of 466
Item 9.i.
City Council
Quarterly Water Supply and Demand Update
May 26, 2026
Page 2
ANALYSIS OF ISSUES:
As of May 14, 2026, the USDA Drought Monitor reports San Luis Obispo County as
normal. Lopez Lake is at 86.8% (42,962 acre feet). The deep well index for the second
quarter of 2026 was completed on April 14, 2026. The index level was 11.87 feet above
sea level, which is 4.27 feet above the threshold value. The current deep well inde x is 0.4
feet lower than February 2026, and 0.2 feet lower than April 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
May 13, 2026, was 3.4 cubic feet per second (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 status of the litigation and the City’s water system,
staff have developed a webpage where updates will be published. The webpage 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.
ENVIRONMENTAL REVIEW:
No environmental review is required for this item.
Page 166 of 466
Item 9.i.
City Council
Quarterly Water Supply and Demand Update
May 26, 2026
Page 3
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. Operation Report for April 2026
2. Lopez Lake Reservoir Storage Projections
3. Previous Use Comparison
4. Deep Well Index Levels for 2nd Quarter
Page 167 of 466
Page 168 of 466
Page 169 of 466
Page 170 of 466
Page 171 of 466