CC 2024-03-26_09c Monthly Water Supply and Demand UpdateItem 9.c.
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: March 26, 2024
SUMMARY OF ACTION:
The update reports the City’s total water supply and demand for February 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:
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 2023/2024 includes 2,290 -acre feet from
Lopez Reservoir, 1323-acre feet of groundwater entitlement from the Santa Maria River
Groundwater Basin, and 160-acre feet from the City’s wells that draw from the Pismo
formation.
The projected water use for 2023/2024 water year is 2,000-acre feet.
In February 2024, the City’s water use was 113.9-acre feet with a per capita use of 72
gallons per day/per person. The residential per capita use was 55 gallons per day/per
person. There was a total of 4.02 inches of rainfall in the City in February 2024.
ANALYSIS OF ISSUES:
The United States Drought Monitor, as of March 13, 2024, shows San Luis Obispo County
is not in a drought. Rainfall for the period of July 1, 2023, through March 13, 2024, is
14.05 inches at the Corporation Yard rain gauge. Lopez Lake is at 100.4 % capacity as of
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Item 9.c.
City Council
Monthly Water Supply and Demand Update
March 26, 2024
Page 2
March 13, 2024. The lake began spilling on February 7, 2024, and is currently spilling at
a rate of 81.5-acre feet/day, which is 26,600,000 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 i n accordance with
Government Code Section 54954.2.
ATTACHMENTS:
1. Monthly Operations Report
2. Lopez Reservoir Storage Projection
3. Yearly Water Use Comparison
4. Deep Well Index Levels
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111 113.3
72 72
0
20
40
60
80
100
120
Feb-23 Feb-24
Yearly Water Use Comparison
Acre Feet Usage (gpcd)
Attachment 3
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Attachment 4
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