Assessing the Impacts of Cannabis Cultivation on Water Use in the North Coast Region of California Five Years Post Legalization

Cannabis cultivation is known to have many adverse impacts on the environment some of which include dewatering of streams from direct diversions, pollution, sediment erosion, and wildlife poisoning from pesticide use. While policies have been developed to mitigate these impacts, their effectiveness is difficult to quantify due cannabis’ long illicit history and limited availability of information. However, there is a critical need for understanding the true extent of cannabis impacts as the newly legalized industry continues to grow. This research assessed existing literature on known environmental impacts, what factors drive or hinder compliance, and examined annual water use reports submitted by cultivators in 2018, 2019, and 2020 in Humboldt, Mendocino, and Trinity Counties respectively to determine if any new insight can be obtained. There has been a steady increase in cannabis licenses issued in the North Coast Region between 2018 and 2020. While there is a general willingness among growers for compliance, high compliance costs and confusing regulatory requirements have deterred many cultivators from applying for permits in the first place. As a result, many are continuing to cultivate unregulated despite the risk of law enforcement. As California’s cannabis program enters its fifth year, continued research and enforcement efforts are still needed to fill knowledge gaps. Therefore, the recommendations in this report focus on the need for further analyses of cannabis applications and reported water use data as well as improved outreach and enforcement efforts to educate the public on cannabis cultivation regulatory program and its requirements