The external pressures for cannabis cultivation and the immediate need for water use regulation may provide opportunities for broader, long-sought environmental objectives in California. Specifically, legislation and state programs regulating water use for cannabis cultivation could produce collateral benefits for environmental instream flow and water quality management in general.
The Medical Cannabis Regulation and Safety Act included several state laws from 2015 and 2016. Of these, Assembly Bill 243 and Senate Bill 837, passed in October 2015 and June 2016, respectively, include several provisions for regulating water use for cannabis cultivation.
Assembly Bill 243 established responsibilities for state agencies to regulate the impact of medical marijuana cultivation on the environment. The bill called for several agencies, including the California Department of Fish and Wildlife and the California State Water Resources Control Board (SWRCB), to reduce the effects of cultivation on the environment and required the SWRCB to regulate marijuana cultivation water use and waste discharge.
The bill also has the California Department of Food and Agriculture administer a cultivation licensing system. These state agencies would coordinate with local agencies to enforce environmental cultivation regulations. Senate Bill 837 required the California Department of Fish and Wildlife and SWRCB to further develop water diversion and use standards for cannabis cultivation. The bill also requires that cultivators specify water diversion sources and report diversion amounts to the SWRCB at least annually.
This previous legislation was adopted into the Medicinal and Adult-Use Cannabis Regulation and Safety Act, enacted as Senate Bill 94 in June 2017. This bill increased regulatory authority for state agencies in permitting and required cultivators to report additional cultivation specifications.
With these laws, several state agencies were tasked with developing programs and policies to regulate and enforce cultivation water use. The table below summarizes the main state agencies involved in developing regulation and the primary purpose of each policy and program.

State agencies involved in regulating cannabis water use.
The SWRCB, working with the California Department of Food and Agriculture and California Department of Fish and Wildlife, developed the Cannabis Cultivation Policy: Principles and Guidelines for Cannabis Cultivation, released in October 2017. This policy outlines regulatory jurisdictions for state agencies regarding water quality, waste discharge, groundwater use, instream flow, monitoring, licensing and enforcement requirements for cannabis cultivation.
An exemption from the California Environmental Quality Act allowed timely development of statewide instream flow requirements. The policy establishes 14 regional boundaries for cultivation water use regulation and identifies nine priority regions with sensitive salmon migration habitats, shown below.
The immediate need for cultivation regulation and the development of these state agency programs, which call for environmentally focused regulations of water quality and flows, has provided an opportunity to expedite long-sought environmental objectives and flow regulations for streams affected by cannabis production, and perhaps environmental flow management in general.
Progress on environmental flow management often seems slow or stalemated in California. External pressures for cannabis cultivation and its regulation could bring broader progress and precedence on instream flow and water quality management.
Water policy often moves in mysterious ways. External forces sometimes are needed to innovate over the status quo. Just as a drought was needed to finally bring groundwater management to California, perhaps marijuana is needed to bring more effective environmental management to California’s streams.
This story first appeared on California WaterBlog, published by the University of California, Davis Center for Watershed Sciences.
The views expressed in this article belong to the author and do not necessarily reflect the editorial policy of Water Deeply.