Marijuana is the top cash crop in California and nationwide. In 2005, the U.S. Deptartment of Agriculture found that the average production value of marijuana—more than $30 billion—far exceeded the value of corn or soybeans. More recent numbers indicate that the value of marijuana exceeds the combined value of corn and soybeans, but these market estimates vary widely. Marijuana is an exceptionally water-loving crop. A pilot study by the California Department of Fish and Wildlife (CDFW) found that concentrated marijuana cultivation has the potential to completely dewater streams and other sources of water (e.g. mountain seeps and springs). The most common method for securing water for growing cannabis is siting grow operations in locations with reliable year-round water sources to draw upon. It is no coincidence that the so-called “Emerald Triangle”—the most productive region for cannabis in the country—is located in the part of California that receives the most average rainfall. In regions with less water and/or during recent drought years when precipitation levels dropped, CDFW also documented the groundwater use for grow operations and importing water by truck. These findings are significant, particularly during the third year of California’s historic drought. Despite a statewide law that allows for the legal cultivation, sale, and use of marijuana, illegal grow operations have proliferated especially in the past two decades. Every year, California authorities receive complaints about marijuana on public lands, often involving armed trespassers who divert water from local sources. Many of these operations are secretly set up in protected wilderness areas that provide limited habitat for vulnerable species, like salmonids and fishers. In addition to high-volume water use, chemical fertilizers and rodenticides have impacted local and downstream water resources as well as wildlife. California’s medical marijuana law and subsequent regulations allow California residents who are U.S. citizens to obtain a doctor’s recommendation (often via quick and remote video consultations), and then to grow and/or purchase, possess, and use marijuana and marijuana extracts at almost any time. This law directly violates the federal Controlled Substances Act (CSA), but the tide is clearly shifting against established federal law. Twenty states have legalized cannabis for medical and/or recreational use already, and more will consider similar measures in the coming months and years. Federal lawmakers have already relaxed certain standards regarding law enforcement, and are considering a bill that would remove hemp from the CSA definition of marijuana, reclassifying it as an agricultural commodity (as states like Indiana and Kentucky have already done). Under existing California law, certain limits apply to growers and certain rules to dispensaries, but in general the industry lacks oversight or regulation. As a result, applicable environmental and land use laws can be disregarded by individuals who cultivate marijuana, and comprehensive information about California’s cannabis industry at-large—e.g. how much is grown, where and how it is grown, where and how it is marketed, sold, and used, how it impacts local water and wildlife—is completely lacking. The federal Bureau of Reclamation, which oversees management of federal water resources and programs like the Central Valley Project, has investigated water use for marijuana and advised local irrigation districts that federally-managed and subsidized water may not be used for purposes that are illegal under federal law, including marijuana production. Insofar as marijuana cultivation leads to violations of existing federal laws like the Endangered Species Act, state and federal authorities can become involved. Enforcement activities regularly include arrests and seizure of plants and equipment. A recent raid next to the City of Modesto Water Treatment Plant uncovered elaborate irrigation equipment and approximately two tons of garbage and hazardous materials, as well as 4,216 plants equivalent to 2,000 pounds—worth approximately $12.6 million. At another raid in Napa County, law enforcement officials eradicated nearly 14,000 plants estimated to be worth $13.9 million. Meanwhile, California lawmakers regularly consider statewide measures intended to close loopholes in the 1996 law, often including proposals for full legalization of recreational marijuana use (the most recent proposal for recreational use was delayed until 2016). Other proposals including one that passed the state Senate last week, would give state agencies the ability to regulate marijuana and enforce basic environmental, public health, public safety, and licensing standards. While these state and federal debates continue, some communities have stepped up to address local concerns and prevent ongoing environmental harm in the near-term. Lake County, for example, recently passed an ordinance limiting certain marijuana-related activities, e.g. requiring setbacks from schools, parks, and bodies of water. Major financial incentives for marijuana production will continue to provide powerful motivation for illegal grow operations and distribution activities, at least until the risks are perceived to outweigh the benefits. At the same time, state authorities have few options for assessing the environmental impacts of cannabis cultivation or for determining exactly how many acres of California land (and acre-feet of increasingly precious California water) is being devoted to marijuana production. Until the patchwork of local, state, and federal regulation is addressed in a comprehensive way, California is very likely to remain the “wild-wild west” of cannabis cultivation. This article was authored by Annie Beaman and was originally published by Rural California Report. Ms. Beaman is an independent consultant working on water issues and sustainable agriculture in California. COPYRIGHT © 2014 CALIFORNIA INSTITUTE FOR RURAL STUDIES. REPRINTED BY PERMISSION.