Big Valley (Lassen, Modoc)
Statistics
- Basin Name
- Big Valley (Lassen, Modoc)
- Basin Number
- 5-004
- SGMA Basin Priority
- Medium
- Critically Overdrafted
- No
- Hydrologic Region Name
- Sacramento River
- Counties
- Lassen, Modoc
- Adjacent Basins
-
Round Valley 5-036,
Basin Notes
2014: CASGEM Basin Prioritization– Medium. Comment: Declining groundwater levels across much of the basin.
2018: Phase 1 (FINAL) basin prioritization – Medium
2022: January 27 – GSP submitted to DWR
2023: October 26 – GSP deemed incomplete
2025: February 27 – GSP approved
At-A-Glance
California Water Library Documents About This Basin
California's Groundwater Conditions: Semi-Annual Update May 2025
California Department of Water Resources (DWR) | June 24th, 2025
This semi-annual report presents data received by DWR as of April 2025 and reflects the impacts of a few wet years after a drought period. However, it should be noted tha
Statement of Findings Regarding the Approval of the Big Valley Basin 2024 Groundwater Sustainability Plan
California Department of Water Resources (DWR) | February 27th, 2025
Sustainable Groundwater Management Program Groundwater Sustainability Plan Assessment Staff Report – Big Valley Basin (No. 5-004)
California Department of Water Resources (DWR) | October 26th, 2023
Big Valley Groundwater Sustainability Plan
Lassen and Modoc Counties Groundwater Sustainability Agencies | December 8th, 2021
The Big Valley Groundwater Basin (BVGB, Basin, or Big Valley) lies on the border of Modoc and Lassen counties in one of the most remote and untouched areas of California.
Bulletin No. 58 Northeastern Counties Investigation
California Department of Water Resources (DWR) | December 3rd, 1957