Study shows that growing cannabis uses less water than previously thought

A study by the University of California’s Berkeley Cannabis Research Center found that licensed cannabis growers use less water than previously thought. Researchers at the center began studying water use by cannabis growers in 2017 after recreational marijuana was legalized in California the previous year.

The data for the study was collected from water usage reports from growers licensed to grow cannabis and from anonymous farmer surveys. Research found that cannabis farmers water their crops with water from a variety of sources, including streams, wells, captured rainwater, springs, and municipal water systems. Researchers found that most regulated cannabis establishments use water from groundwater wells.

“There is growing concern about the effects of cannabis farming on the environment and water resources in particular, but data on cultivation practices and water use patterns have been limited,” the study authors write, adding, “The current study uses data” reported by participants in the cannabis North Coast Regional Water Quality Control Board’s program in California to model how variations in cultivation practices and uses of stored water affect the timing and amount of water withdrawn from the environment. “

Van Butsic and Ted Grantham, co-directors of the Cannabis Research Center and Adjunct Fellows at the Public Policy Institute of California’s Water Policy Center, told local media that the study “did not find that cannabis was particularly thirsty when compared to other plants “.

“Legal outdoor production uses about the same amount of water as a crop like tomatoes,” said Bustic.

Natalynne DeLapp, executive director of the Humboldt County Growers Alliance, noted that the average size of a cannabis farm in Humboldt County is about half an acre, while most farms for other agricultural products can be hundreds or even thousands of acres.

“When you add it all up, we estimated that a single large almond farm in the Central Valley uses 33 times more water than all licensed Humboldt cannabis farms combined,” said DeLapp.

“Another way to look at thirst is to see how much power a single gallon of water produces,” she continued. “With other crops such as tomatoes, lettuce or almonds, a gallon of water yields between a tenth and two cents in value. For cannabis, a gallon of water is worth nearly $ 7. In this sense, cannabis is by far the most water-efficient agricultural product in California. “

Study data says it all

Hezekiah Allen, Director of Education at A Therapeutic Alternative Licensed Medical Pharmacy in Sacramento, has worked in the California cannabis industry for most of his life and has been closely involved with cannabis policy for the past decade. He says the UC Berkeley study was “an ‘I told you’ moment” to me. While the environmental impact of unregulated cannabis in California is substantial and grave, the discussion has long been plagued by a lack of data and poor data due to prohibition stigma. “

“This report is a landmark in that it advances solid science and realistically estimates the effects of cannabis irrigation,” Allen wrote in an email to the High Times. “It is noteworthy that growing cannabis is a water-light culture. Nevertheless, the dependence on hydrologically connected groundwater is a real threat to sensitive and threatened rare aquatic highland habitats. “

Allen said innovative regulations can help cannabis growers use water efficiently, noting that in 2016 he worked with more than 1,000 growers and business owners to create a pioneering policy to introduce a new type of water law for small irrigation systems, especially cannabis growers, to advance.

“This small registration of irrigation use gives cannabis growers an optimized way to store plenty of water for the rainy season to use later during the dry season,” said Allen. “With this approach, we can ensure that cannabis is not only California’s most valuable crop, but also the most sustainable. The work of UC Berkeley underscores the importance of this “storage and forbearance” method for cannabis irrigation. “

Tom Wheeler, executive director of the Environmental Protection Information Center, said that while he is concerned about the effects of well water use on springs and surface water flows, overall “the cannabis model is a good one”.

“That doesn’t mean there aren’t any potential problems with cannabis production and water use,” Wheeler said. “I think industry in general has done a better job figuring out how to use a more limited and precious resource than other forms of agriculture. Hopefully cannabis is the first step towards better regulation for other forms of agriculture. “