CC 2024-07-23_09h Monthly Water Supplu and Demand UpdateItem 9.h.
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: July 23, 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 1323 Acre Feet.
An additional 160 Acre Feet of groundwater is available from the Pismo formation.
The predicted water use for 2024/2025 water year is 2,100 Acre Feet.
In June 2024, the City’s water use was 205.5 Acre Feet with a per capita use of 124
gallons per day/per person. The residential per capita use was 96 gallons per day/per
person. There was a total of 0.0 inches of rainfall in the City in June 2024.
Attachment 3 shows current monthly water use as compared to the previous year’s
month. Staff has provided a “Commercial Usage Portion of Production” as an additional
information point.
ANALYSIS OF ISSUES:
The United States Drought Monitor, as of July 12, 2024, shows San Lu is Obispo County
is not in a drought. Rainfall for the period of July 1, 2023, through June 30, 2024, is 18.40
inches at the Corporation Yard rain gauge. The last two years have provided 50 inches
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Item 9.h.
City Council
Monthly Water Supply and Demand Update
July 23, 2024
Page 2
of rainfall. Lopez Lake is at 98.5% capacity as of July 12, 2024. Lopez Lake stopped
spilling on June 16, 2024.
The deep well index for the second quarter of 2024 was completed on April 17, 2024, and
is 13.81 feet above sea level, which is 6.31 feet above the threshold value. The current
deep well index is 1.48 f eet higher than January 2024, and 1.58 feet higher than April
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 June
2. Lopez Reservoir Storage Projection for June
3. Monthly Water Use Comparison for June
4. Deep Well Index Levels
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24.2168.110229.6205.5124050100150200250Commercial Usage Portion of ProductionAcre Feet ProductionUsage (gpcd)Monthly Water Use Comparison June 2023June 2024ATTACHMENT 3Page 179 of 184
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