Instream Flow Program Documents

Information on current and completed instream flow studies are presented in alphabetical order.

• Big Sur River
• Butte Creek
• Deer Creek
• Fresno River Watershed Criteria Report (PDF)
• Mark West
• Mattole River Watershed Criteria Report (PDF) New - Added June 2025
• Mill Creek
• Navarro River Watershed Criteria Report (PDF) New - Added June 2025
• Scott River and Shasta Rivers
• South Fork Eel River
• Ventura River
• West Fork San Gabriel River Watershed Criteria Report (PDF) 

The Instream Flow Program has developed several short documents to communicate new or essential information about different elements of the program, flow assessment methods, and tools. 

• Overview of Instream Flow (PDF)
• Quality Assurance Program (PDF)
• Standard Operating Procedures (PDF)
• Common Methods and Models (PDF)
• Low Flow Threshold Fact Sheet (PDF)
• The California Environmental Flows Framework (PDF)
• Watershed Criteria Fact Sheet (PDF)
• Functional Flows Fact Sheet (PDF)
• Two-Dimensional Modeling Fact Sheet (PDF)
• Two-Dimensional Modeling of the Ventura River Fact Sheet (PDF)
• Instream Flow and Habitat Suitability Criteria (PDF)
• Groundwater-Dependent Ecosystem Fact Sheet (PDF)

• SOP for Discharge Measurements in Wadeable Streams in California (PDF)
  • CDFW Discharge SOP Data Forms (Excel) 
• SOP for Streambed and Water Surface Elevation Data Collection in California (PDF)
  • Streambed and Water Surface Elevation Data Forms (Excel)
• SOP for Flow Duration Analysis in California (PDF)
• SOP for Critical Riffle Analysis for Fish Passage in California (PDF)
  • Workbook for Critical Riffle Analysis for Fish Passage (Excel)
  • Updated Critical Riffle Field Form (Excel)
• SOP for the Habitat Retention Method in California (PDF)
• SOP for the Wetted Perimeter Method in California (PDF) 

Additional guidance documents are available to assist instream flow practitioners in the development of complete, consistent, and defensible instream flow studies.

• Instream Flow Study Results Checklist (PDF)

• Mesohabitat Delineation Guidance for Instream Flow Hydraulic Habitat Analysis (PDF)

• Study Site and Transect Location Selection Guidance for Instream Flow Hydraulic Habitat Analyses (PDF)

The Instream Flow Program produces a public report each year to provide updates on flow studies and program activities, spotlight available tools, and continue public outreach. The current report is listed below. Archived reports may be found in the Document Library.

2024 Annual Report (PDF)

• Hwan, J. L. and R. W. Holmes (2020). Flow regimes in coastal California steelhead trout streams: Spatiotemporal patterns in magnitude, duration and timing. River Research and Applications 36: 247-258. (PDF)
• Cowan, W. R., D. E. Rankin and M. Gard (2016). Evaluation of Central Valley spring-run Chinook Salmon passage through Lower Butte Creek using hydraulic modelling techniques. River Research and Applications 33(3): 328-340. (PDF)
• Holmes, R. W., D. E. Rankin, E. Ballard and M. Gard (2016). Evaluation of steelhead passage flows using hydraulic modeling on an unregulated coastal California river. River Research and Applications 32: 697-710. (PDF)
• Holmes, R. W., M. A. Allen and S. Bros-Seeman (2014). Seasonal microhabitat selectivity by juvenile steelhead in a central California coastal river. California Fish and Game 100(4): 590-615. (PDF)

• Priority Streams List, 2008 (PDF)
• Historical Flow Recommendations Summary Report, 2008 (PDF)
• Instream Flow Recommendations Map