Cannabis (Cannabis sativa) agriculture is rapidly increasing throughout California following legalization of adult recreational marijuana in 2016. In response, regional research and regulatory policies are addressing current and historic water use for cannabis cultivation and its environmental implications. However, research has yet to explicitly explore how climate-induced changes in water supply impact water-use availability for cannabis and the anticipated ecological tradeoffs of this industry’s growth. This is especially pertinent for growers in northern California, where surface water supply is dependent on atmospheric rivers (ARs) and surface water use is heavily regulated to protect sensitive aquatic species. To understand water availability concerns for cannabis cultivation in northern California (Humboldt, Trinity, and Mendocino Counties), we analyzed both hydro-climate data and relevant news media articles. First, we used correlation and regression analysis to determine how ARs impact cannabis water-user access to surface water diversions given current water management policies. This analysis used streamflow data and instream flow criteria from 18 northern California gages (1980-2019) and a landfalling AR reanalysis dataset (1948-present). Second, we conducted a content analysis of local, regional, and national news articles (2015-2019) to characterize how interactions between water, climate, and cannabis are represented through media coverage across stakeholder perspectives.
Results/Conclusions
Preliminary results show that seasonal surface water availability for cannabis cultivation is variable and modulated by large-scale climate features. From 1980-2019, the average number of legal diversion days for cannabis growers ranged from 25 days (in 2014 during California’s most recent drought) to 128 days (in 2017 during an extremely wet year). Our analysis supports a strong relationship between the number of annual ARs and number of days where surface water diversions for cannabis are permitted (R=0.72). Despite this relationship, cannabis and water use discussions in news media seldom focus on climatic drivers of surface water availability. Rather, most media coverage represents the controversiality of water for cannabis cultivation and its presence in the Emerald Triangle. Major concerns are largely related to surface water supply, current protection of sensitive aquatic species, and the viability of regulating illicit water activity. Given the rapid expansion of this industry, social-ecological challenges associated with water use are likely to amplify in the face of a changing climate. The strong relationship between AR events and surface water availability, paired with the lack of public concern for these changing trends highlights the need for more long-term climate planning for cannabis agriculture.