Cannabis Cultivation Existing Flow Requirements

Existing Flow Requirements

Many rivers in California have existing instream flow requirements through licenses issued by the Federal Energy Regulatory Commission for hydropower projects, Biological Opinions issued by the National Marine Fisheries Service or the United States Fish and Wildlife Service, or water right orders and decisions issued by the State Water Resources Control Board (State Water Board). This webpage provides a comprehensive list of existing instream flow requirements in California, as reflected to the best knowledge of State Water Board staff.  While this webpage was developed to assist cannabis cultivators with compliance with the Cannabis Policy, it has utility beyond cannabis cultivation. Cannabis cultivators should refer to the Cannabis Cultivators section below.

The estimated geographic extent of each requirement is represented by a polygon layer in the interactive GIS mapping tool below. Clicking on a polygon will provide an overview of the flow requirement for the applicable stream reach. More information on the existing instream flow requirements is located below the mapping tool and is organized by Cannabis Policy region and stream reach. The associated compliance gages are also included, as applicable.

While the goal of this website is to compile a comprehensive list of existing instream flow requirements in California, the list may be incomplete and the estimated geographic extent of the flow requirements may have been misinterpreted. If you have comments, corrections, or additional information, you are encouraged to contact State Water Board staff by email at

Cannabis Cultivators:

Per the Cannabis Policy, cannabis cultivators shall comply with either: (a) existing instream flow requirements (e.g., Biological Opinion or Federal Energy Regulatory Commission license flow requirements); or (b) the Cannabis Policy Tessmann instream flow requirements, whichever is greater. Cannabis cultivators should refer to the Online Cannabis Policy Compliance Gage Mapping Tool (online mapping tool) to determine whether an existing flow requirement may apply to their point of diversion.

Cannabis Policy Regions:


Klamath River

Upper Sacramento

McCloud River

Pit River

North Eastern Desert

No Existing Flow Requirements

North Coast

Eel River

Mattole River

Middle Sacramento

Battle Creek

Butte Creek

Sacramento River

Southern Sacramento

American River

Middle Fork American River

South Fork American River

Feather River

North Fork Feather River

South Fork Feather River

Mokelumne River

Putah Creek

Sacramento-San Joaquin Bay Delta Legal Boundary and Major Tributaries

Yuba River

North Yuba River

Middle Yuba River

North Central Coast

Russian River


Upper Truckee River

South Central Coast

San Gregorio Creek

San Joaquin

Merced River

Old River

San Joaquin River

South Fork San Joaquin River

Stanislaus River

North Fork Stanislaus River

Middle Fork Stanislaus River

South Fork Stanislaus River

Tuolumne River

Willow Creek


Mammoth Creek

Pine Creek


Kern River

Kings River

North Fork Kings River

Tule River

Middle Fork Tule River

South Coast

Piru Creek

Santa Ana River

South Eastern Desert

No Existing Flow Requirements