Santa Clara River Valley – Piru
Statistics
- Basin Name
- Santa Clara River Valley – Piru
- Basin Number
- 4-004.06
- SGMA Basin Priority
- High
- Critically Overdrafted
- No
- Hydrologic Region Name
- South Coast
- Counties
- Ventura
Basin Notes
2003: Bulletin 118 basin description
2014: Basin prioritization: high. Comment: GW quality impacts: nitrates, storm runoff, leaking tanks, etc. (B‐118). High Selenium and other inorganics, average TDS was 1450 mg/l (Ventura co 2011 annual GW report)
2018: Draft basin priority: high. Comments on groundwater level decline, salt intrusion subsidence –
- CASGEM/WDL/GWIDS: Longterm hydrographs show groundwater level decline. Source: DWR 2) Groundwater level decline shown 2014-2015 Piru and Fillmore basins Biennial Groundwater Conditions Report, United Water Conservation District
- Salt intrusion: 1) Water purveyors in the Piru, Fillmore, Santa Paula, Mound, and Oxnard subbasins include United Water Conservation District and Ventura County. United Water Conservation District operates surface water facilities to encourage groundwater protection through conjunctive use (UWCD 2012). Groundwater issues within the United Water Conservation District service area (which includes all of the basin) include overdraft conditions, sea water intrusion, and high nitrate concentrations. Source: Long Term Operation EIS, Chapter 7, U.S. Bureau of Reclamation (USBR)
- Subsidence: Subsidence: Section 2.8 (2013); Figure 2.8 shows subsidence zones based on best available data (1973). Subsidence zones not updated due to lack of geodetic survey data. Source: Ventura County General Plan Hazards Appendix 2013
Comments on draft 2018 SGMA basin prioritization Basin boundary modification request pending with Fillmore and Santa Paula subbasins
2019: Basin boundary modification approved. Per DWR: It “contains three components. The first part is a jurisdictional boundary modification to the Santa Paula and Filmore subbasins that shifts the existing shared boundary to align with the eastern extent of the adjudicated Santa Paula subbasin – this results in non-adjudicated areas being added to the Fillmore subbasin. The second part is a scientific boundary modification to the shared boundary of the Piru and Fillmore subbasins. Geologic maps and groundwater elevation data support the shared boundary location at a steep groundwater gradient inflection point. The third part of the request is a scientific modification to the external boundaries of the Filmore and Piru subbasins. The supporting information follows geologic contacts on a qualified geologic map to delineate the proposed boundary revisions. Four letters of support are associated with the request. Each part of the request meets regulatory requirements and supplies sufficient scientific rationale where needed.” Draft priority: high
2022: January 26 – GSP submitted to DWR
2024: January 18 – GSP deemed incomplete by DWR
At-A-Glance

California Water Library Documents About This Basin
Statement of Findings Regarding the Approval of the Santa Clara River Valley – Piru Subbasin 2024 Groundwater Sustainability Plan
California Department of Water Resources (DWR) | February 27th, 2025
Piru Basin Groundwater Sustainability Plan Final (Revised)
Fillmore and Piru Basins Groundwater Sustainability Agency | July 8th, 2024
Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13
Establishing ecological thresholds and targets for groundwater management
Nature Portfolio (Springer Nature) | April 3rd, 2024
Groundwater is critical for many ecosystems, yet groundwater requirements for dependent ecosystems are rarely accounted for during water and conservation planning. Here w
Statement of Findings regarding the Determination of Incomplete Status of the Santa Clara River Valley – Piru Subbasin Groundwater Sustainability Plan
California Department of Water Resources (DWR) | January 18th, 2024
The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP or Plan) conforms to specific requirements
Piru Basin Groundwater Sustainability Plan
Fillmore and Piru Basins Groundwater Sustainability Agency | December 16th, 2021
The Piru Basin (the Basin) is managed (along with the downslope Fillmore Basin) by the Fillmore and Piru Basins Groundwater Sustainability Agency (Agency). The Basin is p
Status and Understanding of Groundwater Quality in the Santa Clara River Valley, 2007: California GAMA Priority Basin Project
U.S. Geological Survey (USGS) | September 26th, 2011
Groundwater quality in the approximately 460-square-mile Santa Clara River Valley study unit was investigated from April through June 2007 as part of the Priority Basin P
Simulation of Ground-Water/Surface-Water Flow in the Santa Clara–Calleguas Ground-Water Basin, Ventura County, California
U.S. Geological Survey (USGS) | July 15th, 2003
Ground-water is the main source of water in the Santa Clara–Calleguas ground-water basin that covers about 310 square miles in Ventura County, California. A steady incr
Bulletin No. 122, Ventura County and Upper Santa Clara River Drainage Area Land and Water Use Survey, 1961
California Department of Water Resources (DWR) | April 1st, 1965
Water Supply Conditions in Southern California during 1958-1959, Volume II, Water Level Data, Central Coastal and Los Angeles Regions
California Department of Water Resources (DWR) | May 1st, 1961
Bulletin No. 39-58, Water Supply Conditions in Southern California during 1957-1958, Volume II, Precipitation and Water Level Data, Central Coastal and Los Angeles Regions
California Department of Water Resources (DWR) | August 1st, 1960
Bulletin No. 39-57, Water Supply Conditions in Southern California during 1956-1957, Volume II, Precipitation and Water Level Data Central Coastal and Los Angeles Regions
California Department of Water Resources (DWR) | June 16th, 1958
Bulletin No. 39-57 Volume I Bulletin No. 39-57 Volume III Bulletin No. 39-57 Volume IV