CC 2024-04-23_09e Monthly Water Supply and Demand UpdateItem 9.e.
MEMORANDUM
TO: City Council
FROM: Bill Robeson, Assistant City Manager/Public Works Director
BY: Shane Taylor, Utilities Manager
SUBJECT: Monthly Water Supply and Demand Update
DATE: April 23, 2024
SUMMARY OF ACTION:
The update reports the City’s total water supply and demand for March 2024. Current
Lopez Reservoir level and projected levels are provided in the attachments.
IMPACT ON FINANCIAL AND PERSONNEL RESOURCES:
Approximately two (2) hours of staff time is required to prepare the report.
RECOMMENDATION:
Receive and file the Monthly Water Supply and Demand Update.
BACKGROUND:
On March 28, 2023, the City Council adopted a Resolution rescinding the declaration of
a State 1 Water Shortage Emergency and related water shortage restrictions and
penalties.
The City of Arroyo Grande’s water entitlements are calculated on a water year that begins
April 1st. The current water supply for water year 2024/2025 includes 2,290 Acre Feet
from Lopez Reservoir, the current modeled, safe yield is 357 -acre feet of groundwater
from the Santa Maria River Groundwater Basin, with an entitlement of 1323 acre feet from
the City’s wells that draw from the Pismo Formation.
The predicted water use for 2024/2025 water year is 3,100 -acre feet.
In March 2024, the City’s water use was 129.3-acre feet with a per capita use of 76 gallons
per day/per person. The residential per capita use was 58 gallons per day/per person.
There was a total of 3.75 inches of rainfall in the city in March 2024.
Item 9.e.
City Council
Monthly Water Supply and Demand Update
April 23, 2024
Page 2
ANALYSIS OF ISSUES:
The United States Drought Monitor, as of April 11, 2024, shows San Luis Obispo County
is not in a drought. Rainfall for the period of July 1, 2023, through April 11, 2024, is 15.75
inches at the Corporation Yard rain gauge. Lopez Lake is at 100.2% capacity as of April
11, 2024. The lake began spilling on February 7, 2024, and is currently spilling at a rate
of 22.8-acre feet/day which is 7,400,000 gallons/day.
The deep well index for the first quarter of 2024 was completed on January 9, 2024, and
is 12.33 feet above sea level, which is 4.83 feet above the threshold value. The current
deep well index is 1.38 feet higher than October 2023 and 1.75 feet higher than January
2023.
ALTERNATIVES:
The following alternatives are provided for the Council’s consideration:
1. Receive and file the report, or
2. Provide other directions to staff.
ADVANTAGES:
The report provides the City Council and the public with the current and projected
conditions of our water supply and demand.
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
2. Lopez Reservoir Storage Projection
3. Monthly Water Use Comparison
4. Deep Well Index Levels
108.9129.36976020406080100120140Mar‐23 Mar‐24Monthly Water Use ComparisonAcre FeetUsage (gpcd)Attachment 3
Attachment 4