GSP Annual Report
2-002.01 NAPA VALLEY
2022 (OCT. 2021 - SEP. 2022)
Single Annual Report
GSP Annual Report Information Comments
03/29/2023 5:08 PM
2022 (OCT. 2021 - SEP. 2022)
Single Annual Report
A Groundwater Extraction
Total Groundwater Extractions (AF)
25,230
Water Use Sectors
1,520
0
14,210
180
0
6,260
3,060
Self-Supplied Users (e.g., Domestic wells)
B Groundwater Extraction Methods
Meters
450
Direct
90-100 %
Meters and comparable measuring devices operated by municipal water systems in compliance with AWWA and other relevant standards.
Meters are understood to be regularly maintained and tested; therefore, reported data meet high accuracy levels in compliance with AWWA and other relevant standards.
Electrical Records
0
Land Use
0
Groundwater Model
23,710
Estimate
Other
The Napa Valley Integrated Hydrologic Model (NVIHM) developed for the Napa Valley Subbasin GSP was used to estimate the Subbasin water budget and groundwater extraction and use for Water Year 2022. The NVIHM uses MODFLOW-OWHM code to simulate groundwater flow, and other integrated packages, including the Farm Process, to simulate streamflow, evapotranspiration demand, and sources of supply including precipitation, groundwater extraction, surface water, recycled water, and direct uptake of groundwater. Groundwater demand by agriculture and self-supplied users is estimated based on crop and vegetation water demand that is not met by precipitation, surface water, recycled water, and direct uptake of groundwater. Groundwater use by GDEs, other native vegetation, and managed wetlands is also accounted for by the NVIHM and reflects the direct uptake of groundwater by vegetation. Due to the limited availability of some data obtained from other agencies at the time of report preparation, such as water use by small public water systems and surface water diversions reported to the SWRCB, Water Year 2021 groundwater use estimates developed for this Annual Report are considered preliminary and subject to revision in subsequent annual reports and GSP updates.
Medium Accuracy. Typical accuracy associated with water demand estimates developed by regional scale numerical modeling methods. See Section 8 and Appendix 8A of the 2022 Napa Valley Subbasin GSP for more information.
Other
1,070
Estimate
Other
Groundwater extraction by Small Public Water Systems in 2022 were estimated based on historical data available in the SWRCB Electronic Annual Report database. Due to the limited availability of some data obtained from other agencies at the time of report preparation, such as water use by Small Public Water Systems, Water Year 2022 groundwater use estimates developed for this Annual Report are considered preliminary and subject to revision in subsequent annual reports and GSP updates.
Medium accuracy. Other Method Volume corresponds to Small Public Water Systems, where groundwater extraction is self-reported annually and considered high accuracy based on the variability of historical groundwater pumping data reported. WY 2022 is considered to be medium accuracy because it is largely based on historical data.
C Surface Water Supply
Total Surface Water Supply (AF)
15,080
Methods Used to Determine
Due to the limited availability of some data obtained from other agencies at the time of report preparation, such as water use by small public water systems and surface water diversions reported to the SWRCB, Water Year 2022 surface water use estimates developed for this Annual Report are considered preliminary and subject to revision in subsequent annual reports and GSP updates. Self-reported data available in the SWRCB Water Rights Information Management System (eWRIMS) were used to estimate annual surface water diversions by Agricultural Users. When 2022 diversion data were not available in eWRIMS, historical data were used to estimate diversions. Municipal water systems report surface water supplies sourced from State Water Project (SWP) and local reservoirs, and also report SWP supplies sold to Small Public Water Systems and Agriculture. Local reservoir supplies used by Small Public Water Systems in 2022 were estimated based on historical data available in the SWRCB Electronic Annual Report database. Recycled water supplies are reported by Municipal water systems, including recycled water supplies sold to Small Public Water Systems and Agricultural users.
Water Source Types
0
8,290
0
400
5,170
1,220
0
0
D Total Water Use
Total Water Use (AF)
40,302
Methods Used to Determine
Methods used to determine total Subbasin water use include direct measurements made by meters, estimates developed using the Napa Valley Integrated Hydrologic Model, and other estimates made for direct measurements not yet available from other agencies at the time of report preparation. Due to the limited availability of some data obtained from other agencies, such as water use by small public water systems and surface water diversions reported to the SWRCB, Water Year 2022 water use estimates developed for this Annual Report are considered preliminary and subject to revision in subsequent annual reports and GSP updates. Please see the method descriptions provided in other sections of this Annual Report submittal for additional information.
Water Source Types
25,230
13,852
1,220
0
0
Water Use Sectors
15,940
0
14,865
180
0
6,260
3,060
Self-Supplied Users (Domestic wells)
E Change in Storage
Method used to calculate change in storage
The change in groundwater storage result presented here is calculated by the Napa Valley Integrated Hydrologic Model (NVIHM). The NVIHM calculated storage change reflects changes from the start of the water year on October 1, 2021 through September 30, 2022. The NVIHM numerical code is mass conservative (inflows equal outflows including flows to and from groundwater storage). Net change in groundwater storage is a function of groundwater level increases or decreases throughout the Subbasin and inflows or outflows that indirectly induce depletion or accretion of groundwater storage.
F Monitoring Network Module
G PMA Module
PMA Implementation Updates Implementation Update Export (CSV) PMA Export (CSV)
| PMA ID | PMA Name | Lead GSA | Status | # Updates during WY |
|---|---|---|---|---|
| 2-002.01_PMA_1 | Project #1 (P1): Managed Aquifer Recharge | County of Napa GSA | 0 | |
| 2-002.01_PMA_2 | Project #2 (P2): Expansion of Recycled Water Use | County of Napa GSA | 0 | |
| 2-002.01_PMA_3 | Management Action #1 (MA1): Water Conservation (Vineyards, Wineries and Other Water Users) | County of Napa GSA | 0 | |
| 2-002.01_PMA_4 | Management Action #2 (MA2): Groundwater Pumping Reductions | County of Napa GSA | 0 | |
| 2-002.01_PMA_5 | Management Action #3 (MA3): Groundwater Ordinance and New Well Permit Conditions | County of Napa GSA | 0 | |
| 2-002.01_PMA_6 | In-lieu Aquifer Recharge | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_7 | Groundwater Ordinance and New Well Permit Condition | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_8 | County and municipalities revise local codes to align future land use approvals with GSP water budget results and sustainable yield analysis | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_9 | Active Production Well Inventory | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_10 | Tracking Impacts to Drinking Water Users Caused by Groundwater Management | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_11 | Stakeholder Engagement and Outreach | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_12 | Coordination with Land Use and Water Management Agencies | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_13 | Adopt Well Metering and Reporting Standards | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_14 | Model Limitation and Recommendations | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_15 | GSA Collaboration | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_16 | GSP Advisory Committee and Future Advisory Work Group | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_17 | Watershed Information and Conservation Council (WICC) | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_18 | Well Owner Outreach and Education | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_19 | Grower Outreach and Education | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_20 | Participation in Integrated Regional Planning | County of Napa GSA | Submitted | 0 |
| 2-002.01_PMA_21 | Project Financing | County of Napa GSA | Submitted | 0 |
