GSP Annual Report
5-021.57 VINA
2022 (OCT. 2021 - SEP. 2022)
Single Annual Report
GSP Annual Report Information Comments
03/30/2023 12:13 PM
2022 (OCT. 2021 - SEP. 2022)
Single Annual Report
A Groundwater Extraction
Total Groundwater Extractions (AF)
354,700
Water Use Sectors
22,300
0
253,800
0
0
76,000
2,600
Rural Residential
B Groundwater Extraction Methods
Meters
22,300
Direct
10-20 %
Metered Municipal Wells
Metered connection maintained by California Water Service and Durham Irrigation District
Electrical Records
0
Land Use
329,800
Estimate
20-30 %
Land use estimates were derived from crop mapping and LandIQ survey results
Typical uncertainty for water balance calculation
Groundwater Model
0
Other
2,600
Estimate
10-20 %
Rural residential groundwater extraction is estimated based on California Water Service Company's 2020 Urban Water Management Plan 2020 usage of an average per capita water use of 184 gallons per capital per day. Population data from the 2020 census was coupled with parcel data to identify total population not serviced by municipal supplies.
Uncertainties are from population estimates and gpcd estimates
C Surface Water Supply
Total Surface Water Supply (AF)
20,500
Methods Used to Determine
Diversions for local supplies are estimated based on historic State Water Resource Control Board eWRIMS (Electronic Water Rights Information Management System) data for total diversions. Surface water delivery estimates are based on historic deliveries in the area that have occurred in dry and critical years
Water Source Types
0
0
0
20,500
0
0
0
0
D Total Water Use
Total Water Use (AF)
375,200
Methods Used to Determine
Methods used are a combination of estimates based on land use and population/per capita water use, metered municipal water use, and estimates based on historic water rights data for dry and critical years
Water Source Types
354,700
20,500
0
0
0
Water Use Sectors
22,300
0
274,300
0
0
76,000
2,600
Rural Residential
E Change in Storage
Method used to calculate change in storage
Change in groundwater storage was estimated based on change in measured spring-to-spring groundwater levels at each RMS well, multiplied by the area of a Thiessen polygon surrounding that RMS well (defining a representative area for each RMS well) and a representative storage coefficient of 0.1 for the principal aquifer.
