CC 2024-09-24_09g Monthly Water Supply and DemandItem 9.g.
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: September 24, 2024
RECOMMENDATION:
Receive and file the Monthly Water Supply and Demand Update
IMPACT ON FINANCIAL AND PERSONNEL RESOURCES:
Approximately two (2) hours of staff time is required to prepare the report.
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 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 1,323 Acre Feet.
An additional 160 Acre Feet of groundwater is available from the Pismo formation.
The predicted water use for the 2024/2025 water year is 2,100 Acre Feet.
As shown in Attachment 3, the monthly water use for the City in August 2024, was 201.3
Acre Feet, compared to the previous 5-year average of 213.5 Acre Feet. This
demonstrates that water conservation is occurring. The per capita monthly water use for
August 2024 is 118 gallons per day/per person. The residential per capita use was 91
gallons per day/per person. There was a total of 0.0 inches of rainfall in the City in August
2024.
Attachment 3 shows current monthly water use as compared to the previous five-year
average for the month. Staff has provided a “Commercial Usage Portion of Production as
an additional information point highlighting conservation effort.
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Item 9.g.
City Council
Monthly Water Supply and Demand Update
September 24, 2024
Page 2
ANALYSIS OF ISSUES:
The United States Drought Monitor, as of September 13, 2024, shows Sa n Luis Obispo
County is not in a drought. Rainfall for the period of July 1, 202 4, through September 13th,
2024, is 0.0 inches at the Corporation Yard rain gauge. Lopez Lake is at 94.9% capacity
as of September 13, 2024.
The deep well index for the third quarter of 2024 was completed on July 3, 2024, and is
11.57 feet above sea level, which is 4.07 feet above the threshold value. The current deep
well index is 0.66 feet lower than April 2024, and 6.23 feet higher than July 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 for August
2. Lopez Reservoir Storage Projection for August
3. Monthly Water Use Comparison for August
4. Deep Well Index Levels for 3rd Quarter
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30.7213.512529201.3118050100150200250Commercial Usage Portion of Production Acre Feet Production Usage (gpcd)Monthly Water Use Comparison Attachment 3Previous 5‐year average for August August 2024Page 104 of 117
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