Pot Is Making California’s Epic Drought Worse

Marijuana growers in Northern California are worsening local effects of the historic drought that has gripped the state for the past four years, according to a new study from the California Department of Fish and Wildlife.

Creeks in Humboldt County, a major pot-growing region, are going dry during the May-September outdoor growing season, which also happens to be the driest period of the year, even when there is no drought.

The average marijuana plant consumes about six gallons of water a day. The report compares this to another Northern California plant: wine grapes, which take about 3.3 gallons per day (one-to-one comparisons of two totally different plants are a blunt measure, but still give a roughly useful basis for comparison).

Based on analyses of stream-flow data, aerial observation, and estimated demand, the researchers found that pot growers are in some cases using more water than local creeks can support, putting local wildlife — including the salmon and trout that use the streams — in danger. Young salmon spend their first year of life in those streams before heading to the ocean, spending two years there, and returning to spawn — that is, if there’s enough water. If there isn’t, they can die. This disrupts not only the fishing industry, but the whole food chain, since many local critters feed on fish.

Water diversion is “likely to have lethal or sub-lethal effects on state-and federally-listed salmon and steelhead trout and to cause further decline of sensitive amphibian species,” according to the Fich & Wildlife report.

The study indicates, as have earlier ones, that a majority of creeks studied in the area are at risk.

With other farming industries, such a problem could be tackled head-on. But marijuana’s murky legal status makes that next to impossible. Under state law, pot is legal in California for medical use. But, because it remains illegal for recreational use, and — especially — because it remains totally illegal under federal law — it’s very difficult to regulate. Pot growers in general try to keep as incognito as possible. They don’t apply for permits or create other records that would allow the government to amass data.

Generally, farmers are required to secure permits to redirect water from creeks or to release wastewater. That applies to pot growers, too, but the requirement hasn’t been strongly enforced. The California Water Resources Control Board has lately begun to step up enforcement efforts, but state laws are vague on the details of when permits are needed. That, combined with the reticence of pot growers, means addressing the problem will be a major challenge.

Meanwhile, the drought goes on, with no end in sight. The snowpack in the Sierra Nevada mountains, a major source of California’s water, is now at only 9% of normal levels. As this is happening, the pot industry is growing fast. The Fish & Wildlife report estimates that the amount of land devoted to marijuana cultivation nearly doubled between 2009 and 2012.