GSP Annual Report
1-003 BUTTE VALLEY
2022 (OCT. 2021 - SEP. 2022)
Single Annual Report
GSP Annual Report Information Comments
03/27/2023 12:49 PM
2022 (OCT. 2021 - SEP. 2022)
Single Annual Report
A Groundwater Extraction
Total Groundwater Extractions (AF)
81,400
Water Use Sectors
400
0
78,000
3,000
0
0
0
B Groundwater Extraction Methods
Meters
0
Electrical Records
0
Land Use
0
Groundwater Model
78,000
Estimate
60-70 %
Butte Valley Integrated Hydrologic Model
Model results are estimated to have medium accuracy due to documented data gaps.
Other
3,400
Estimate
80-90 %
Population data from DWR (https://gis.water.ca.gov/app/bp-dashboard/final/) to estimate urban water demand. Wetland pumping estimated by the amount needed to flood and maintain about 2,000 acres.
Data source 2010 US Census for basin population. Estimate an average annual water use of 1 acre-foot per 3.5 persons. Wetland estimate from CDFW.
C Surface Water Supply
Total Surface Water Supply (AF)
0
Methods Used to Determine
None. All streams entering the groundwater basin had no functional stream gages in WY 2022 and thus surface water supply cannot be estimated.
Water Source Types
0
0
0
0
0
0
0
0
D Total Water Use
Total Water Use (AF)
81,400
Methods Used to Determine
Methods for groundwater use is the Butte Valley Integrated Hydrologic Model and an estimate based on the Census population in the groundwater basin. Managed wetland water use estimate supplied by CDFW. Applied surface water is a data gap in WY 2022 and an estimate cannot be determined. Applied water for native vegetation water use sector is a data gap.
Water Source Types
81,400
0
0
0
0
Water Use Sectors
400
0
78,000
3,000
0
0
0
E Change in Storage
Method used to calculate change in storage
The change in groundwater storage for the Basin is calculated based on the change in groundwater levels between Fall 2022 and Fall 2021. This change in groundwater level was then multiplied by the aquifer storage coefficients to estimate change in aquifer storage. The groundwater contours are cropped to the extent of the groundwater level monitoring points to avoid low accuracy contours, thus the groundwater storage change is only calculated for the portion of the Basin where there is sufficient groundwater level data. Additionally, groundwater level stations are only used if they exist in both the current and previous year to avoid discrepancies in groundwater contour due to a lack of historic data. As more groundwater level monitoring stations are installed during plan implementation the groundwater contours will cover more of the Basin producing more accurate change in groundwater storage estimates.
