California Drought Caused By Marijuana Cultivation?

As winter turns to spring, the Californian drought has brought on record-setting heat waves as the state records its worst drought in more than a 1,000 years. Now, The California Department of Fish and Wildlife has published a study that has linked the water shortage to the cultivation of marijuana.

The study, which was published in the PLOS journal, reports that "the environmental impacts associated with marijuana cultivation appear substantial, yet have been difficult to quantify, in part because cultivation is clandestine and often occurs on private property."

The study interpreted aerial footage in order to estimate the number of marijuana plants being cultivated in four watersheds in Northwestern California.

According to the study, most of the data used are available via public sources however, "specific spatial locations of marijuana grown cannot be shared due to legal and private concerns."

The study maintained that the water demand for these farms in the growing season far exceeds the supply provided by the streams in some areas of California.

"Our water demand estimates were based on calculations from the 2010 Humboldt County Outdoor Medical Cannabis Ordinance draft, which states that marijuana plants use an average of 22.7 liters per plant per day during the growing season, which typically extends from June-October (150 days)."
The study may have also found delinquency among these marijuana cultivation sites (MCSs). Domestic and agricultural water is primarily obtained from small surface water diversions in many rural watersheds in Northern California. This requires registration with the agency responsible for issuing water rights, the State Water Resources Control Board.

State Water Resources Control Board registrations are also subject to conditions set by the California Department of Fish and Wildlife in order to protect fish, wildlife, and their habitats.

"When querying the State Water Registration Control Board's public database, we found low numbers of registered, active water diversions on file relative to the number of MCSs we counted in the study watersheds. The total number of registered, active diversions on file with the State Water Registration Control Board accounted less than half of the number of parcels with MCSs that were visible from aerial imagery."
The scientists observed that "All the streams we monitored in watersheds with large scale marijuana cultivation went dry" however, the inverse was seen with the only stream that did not go dry had no evidence of marijuana cultivation.

The study concluded that "due to climate change, water scarcity and habitat degradation in northern California is likely to worsen in the future."

Does the study on effects of marijuana cultivation on Northwestern California water supply concern you given the current drought?

(Photo by Justin Sullivan/Getty Images)