Study Says Pot Grows Drying Up Streams In Northern California

Apr 20, 2015

California is four years into a historic drought, and water for human use is vying with the water needs of wildlife, such as threatened salmon.

In parts of northern California, an explosive and unregulated increase in marijuana cultivation is contributing to the problem. Now, a study says the impact of pot grows on fish-bearing streams is threatening their survival.

Credit Wikimedia Commons

Researchers monitoring water levels in streams in Humboldt and Mendocino Counties last summer say the water impacts of cannabis grow operations are dramatic.

Scott Bauer: “What we found is that in four of the streams that had marijuana cultivation, those four streams went dry. And the only stream that we monitored that did not go dry was free of marijuana cultivation.”

Scott Bauer is a biologist with the California Department of Fish and Wildlife. He’s also the lead author of a recently-published study that found the proliferation of unregulated pot grows in the so-called “Emerald Triangle” is dangerously depleting the water needed for survival of salmon and other threatened fish. Bauer says the area has already lost some local fish populations to lack of water.

Scott Bauer: “For coho salmon in particular, they’re on a three-year life cycle. So if we lose three consecutive years of fish in any given watershed, we’ve essentially lost that run of fish.”

Bauer’s report attempts to quantify the problem by estimating the number of pot plants being grown in key watersheds and calculating how much water they use. The results are startling. In some areas, the amount of water calculated to grow marijuana exceeds the amount of water available in the streams.

The report has generated some push-back from growers. The Emerald Growers Association opposes illegal water diversion and promotes environmentally sensitive growing practices. But the group says Bauer’s report overstates the amount of water pot plants require by 300 percent. The group also says the report fails to account for the millions of gallons of stored water that growers use.

Bauer acknowledges that his “six gallons per plant per day” estimate is based on limited data.

Scott Bauer: “But when you go out on the ground and you see streams going dry, it’s hard to dispute that – regardless of what number you want to use – it’s having an impact and it’s impacting salmon and steelhead populations.”

Last year, California lawmakers approved a pilot program designed to get pot growers to abide by land use, water use and environmental laws. Chris Carrigan heads the State Water Resources Board Office of Enforcement, which runs the program. He says so far his teams have made more than 50 on-site inspections of grow operations on private land.

Chris Carrigan: “We’ve issued quite a few notices of violation. Some clean-up and abatement orders which require property restoration. And also some fines and civil penalties for violations of the Clean Water Act.”

Carrigan says inspectors have found everything from illegal water diversions from creeks to unpermitted grading work to unsafe use of pesticides. He says some growers are coming from out of state to cash in on California’s medical marijuana market.

But many others, he says, are like the man who told him, “I’m a third-generation cannabis grower.”

Chris Carrigan: “(He said) My grandfather started growing cannabis on this land in the 1960s. I want to make sure that I preserve the legacy of this property and be a steward of this land.”

Carrigan’s office plans to roll out a permit process soon that would put marijuana farmers under the same regulatory requirements as other land users.

Chris Carrigan: “Treat ‘em like a dairyman. Treat ‘em like a timber harvester. Treat ‘em in the same way that you would treat any other business. Because whether you agree with it or not, in California cultivation of cannabis for medicinal purposes is lawful.”

Carrigan says his program deals only with grows on private property. So-called “trespass grows” on public land, he says, are left to law enforcement.

Jim Wood represents the Second District in the California Assembly. All three counties that comprise the Emerald Triangle are included in his district. Wood is sponsoring a bill that would make the regulatory program Chris Carrigan is piloting permanent and statewide. He says he’s responding to the concerns of many constituents who say pot grows in the region are simply out of control.

Jim Wood: “The number of grow sites has grown dramatically and the pressure on watersheds that is happening because of the unregulated water diversion is really reaching catastrophic proportions.”

Wood says his bill is an effort to establish a regulatory framework for bringing cannabis cultivation into compliance with environmental laws, much like any other agricultural product.

Jim Wood: “If you’re growing tomatoes commercially you’ve got to deal with a permitting process through the county, you’re going to have to deal with water quality control, you’re going to have to potentially deal with water diversion and getting permission to do that, and we just haven’t done that with marijuana.”

But even beyond the bill itself, Wood says he’s trying to send a message to urban marijuana consumers ...

Jim Wood: “There is a price that we’re paying environmentally for the weed that you’re smoking. And you need to be at least aware that that’s happening.”

Wood hopes that awareness might contribute to political support for ending the environmental abuses of a lucrative but unregulated cannabis trade.

Copyright 2015 Jefferson Public Radio.