Watershed-Wide Instream Flow Criteria

CDFW’s Instream Flow Program has initiated the implementation of the objectives described in Section 9 of the Water Resilience Portfolio by supporting rapid flow assessment methodologies to develop watershed-wide instream flow criteria. These instream flow criteria (PDF) are developed using existing hydrologic and modeling tools and are supplemented with site-specific data, when available. Flow criteria are presented for watersheds throughout the state in a series of “Watershed-Wide Instream Flow Criteria” reports (Watershed Criteria Reports).

The Watershed Criteria Reports use approaches and tools developed by the California Water Quality Monitoring Council’s California Environmental Flows Framework (PDF) (CEFF). CEFF provides guidance and a set of tools for developing flow criteria statewide using a functional flows approach, where functional flows are key aspects of the natural flow regime that perform important ecological and geomorphic functions. Functional flows provide the basis for the development of instream flow criteria in the Watershed Criteria Reports, and CEFF tools such as the California Natural Flows Database may be used to provide background hydrological data and generate flow results.

The development of Watershed Criteria Reports aligns with the California Salmon Strategy for a Hotter, Drier Future: Restoring Aquatic Ecosystems in the Age of Climate Change (PDF) (Salmon Strategy). The Salmon Strategy outlines priority actions state agencies are taking to stabilize and recover salmon populations and the riverine habitats upon which they depend. Under the Salmon Strategy, the Instream Flow Program is directed to complete instream flow analyses for priority streams across the state, coordinate with the State Water Board on setting environmental flows, and complete the development of rapid instream flow methodologies through the CEFF.

Overview Document

The Overview of Watershed-wide Instream Flow Criteria Report Methodology document provides background, section by-section explanations, and guidance on interpretation of results and development of flow criteria relevant to all Watershed Criteria Reports.

• Overview of Watershed-wide Instream Flow Criteria Report Methodology (PDF)

Watershed Criteria Reports

Reviewing the Overview document is essential to understanding the results of the analyses and the flow regime criteria contained in these Watershed Criteria Reports.

• Watershed-Wide Instream Flow Criteria for Mark West Creek (PDF)
• Watershed-Wide Instream Flow Criteria for the West Fork San Gabriel River (PDF)
• Watershed-Wide Instream Flow Criteria for the South Fork Eel River (PDF)
• Ventura River Watershed Criteria Report (PDF)
  • Appendix B: Supplemental information on field methods for Ventura River Watershed Criteria Report (PDF)
• Fresno River Watershed Criteria Report (PDF)

Reports are best viewed in the Chrome browser, or downloaded using Firefox or Chrome.