Pot Growers’ Water Use: What You Need to Know

A forthcoming report aims to dispel misconceptions about water usage at cannabis grows, and lay out recommendations to improve water efficiency within the industry.

The “Cannabis Water Report,” prepared by members of the Resource Innovation Institute, New Frontier Data and the Berkeley Cannabis Research Center, is scheduled for release in February 2021. On Tuesday, though, some of the report’s authors gave a sneak peek into its findings during an online forum held as part of MJBizCon, an industry expo.

Key takeaways:

• Despite being commonly referred to as a “thirsty plant,” cannabis actually uses a fraction of the water of other major agriculture crops. 
  • Currently, illicit growers are believed to consume water at a rate of more than three times legal operators, nationwide. The report suggests the water usage from legal growers will nearly double over the next five years, but still be less than half of what illegal growers consume.
  • Including both the legal and illegal cannabis markets, overall water usage is expected to jump from about 6,850 acre-feet to 8,670 acre-feet by 2025.

• Water scarcity will be an “enduring problem” in western states, which make up the largest cannabis-growing region. 
  • This is particularly concerning in California, a state the report notes “points to our grim water-scarce future.” More than half of California was experiencing “exceptional drought” – the worst tier of a five-level drought scale – in 2014, and nearly 85% of the state is currently experiencing “abnormally dry” conditions (the least-impactful tier of the scale).
  • “We’re in the age of climate change, and droughts are increasingly common,” said Derek Smith, executive director of the Resource Innovation Institute. The imperative of figuring out how to be more efficient is not only critical for business operations, Smith added, but also “for the rest of agriculture and humanity.”

• A lack of data has held back efforts to quantify the industry’s water use, but the transition to legal production enables California to establish benchmarks that can be used elsewhere.
  • By tracking water-use info, operators and regulators will be able to better understand productivity and efficiency over time.
  • It is commonly believed that cannabis grows pose a significant threat to some of California’s freshwater resources and endangered fish species. Current research shows that isn’t the case, said Chris Dillis, a researcher at the Berkeley Cannabis Research Center. He noted that wells, not stream diversions, are the water source of choice for most legal cannabis growers. 
  • The wide range of cannabis agriculture – indoor, outdoor, different methods – makes it impossible to standardize water use per plant across the industry. Instead of plant count, the report suggests that evaluation of water efficiency be based on canopy square footage.

• “Significant efficiency gains” will be made in the coming years, driven largely by knowledge-sharing, cost-saving efforts and innovation, according to the research.