Legal cannabis uses less water than you probably think

With California in the midst of another drought, there are growing questions about the impact of the state’s newest legal crop, cannabis. But a new report from the University of California Berkeley Cannabis Research Center says legal marijuana farms don’t use nearly as much water as one might expect.

The researchers relied on data from the North Coast Regional Water Quality Control Board Cannabis Program, so it pertains only to legally-grown crops. Annual data was combed from over 600 farms in the counties of Humboldt, Trinity, Mendocino, and Sonoma. The researchers looked at both water use and water extraction, with special attention paid to storage sufficiency.

The researchers found that permitted, outdoor grows use the same amount of water as many other traditional crops like tomatoes. Because cannabis farms are typically smaller, they often use much less.

Former California Cannabis Growers Association Director Hezekiah Allen called it an ‘I told you so moment.’

“This report is a landmark moment in that it advances sound science and is realistic about the impacts of cannabis irrigation,” Allen wrote in an email to High Times. “Notably, that cannabis cultivation is a water-light crop. But even so, reliance on hydrologically connected groundwater is a real threat to sensitive and threatened rare upland aquatic habitat.”

The study comes amid a worsening water situation in California. On Friday, Gov. Gavin Newsom expanded the drought state of emergency to include 50 counties that comprise around 42% of the population. He has asked residents to voluntarily cut water usage by 15%. The governor has also approved an extra $500 million for wildfire prevention following a scathing Capradio/NPR California report that found he had "overstated, by an astounding 690%, the number of acres treated with fuel breaks and prescribed burns in the very forestry projects he said needed to be prioritized to protect the state’s most vulnerable communities."