Side effects

In a video released last fall by the Humboldt Institute for Interdisciplinary Marijuana Research, Google Earth zooms in on Humboldt County, Calif.'s forested hills. Cruising the ridges from one watershed of this virtual landscape to the next, one gets a bird's-eye view of the hundreds of new roads, out-buildings, and even the tall, leafy pot plants that define northern California's "Green Rush."

All these marijuana farms on private lands are theoretically legal under California law, which allows licensed growers to sell to the state's medical marijuana dispensaries. But because the federal government still regards marijuana as a dangerous and illegal drug, California's marijuana economy straddles a legal question mark that's kept regulation, including enforcement of environmental rules, at bay.

The rise of the cash crop has been especially baffling to the California Department of Fish and Wildlife, which oversees the area's streams. With a separate Google Earth project, the agency recently counted over 1000 "grows" in two watersheds that feed the South Fork of the Eel River, an area less than 60 square miles. The agency estimates that these grows divert as much as 30 percent of summer stream flow, stressing the endangered Coho salmon that spawn there.

Marijuana grows identified by the California Department of Fish and Wildlife in a tributary of the South Fork of the Eel River

"I'm not sure we're at a point where we comprehend the significance of this issue," says Scott Bauer, Coho recovery coordinator with the California Department of Fish and Wildlife. "This is one of the biggest issues for Coho salmon recovery."

Fish and Wildlife wants to collaborate with growers to establish practices, like scheduling water pumping in order to prevent sudden draining of streams, that safeguard water and species like Coho, but the agency faces numerous challenges. Growers are hesitant to apply for water-use permits because they think it might attract federal prosecution. And the agency, which can bust growers for violating stream rules, is overwhelmed by the magnitude of the problem. Since 2009, the number of grows in the two Eel River tributaries has more than doubled, as California's laws have become even more marijuana-friendly -- in 2010 the state's Supreme Court struck down limits on the amount of pot residents can grow or possess -- and growers seek to cash in before more widespread legalization makes the crop less lucrative.

"There's still some misconception that the issue is illegal, Mexican cartel grows" on public lands, says Bauer. Those grows contribute to the overall environmental impact, he says, but "the biggest marijuana cultivation activity is occurring on private lands" under the auspice of providing legalized medical marijuana. Most of the crop actually goes to illicit recreational markets out of the state.

Humboldt State University faculty member Tony Silvaggio, who made the Google Earth video of marijuana grows, says this lack of regulation is causing all kinds of environmental problems, not just low stream flows. Sediment run-off from new roads and pesticides is degrading water and rodent poisons are killing off forest critters and birds. High Country News and others have reported on these problems before, but it can be hard to visualize the impact and scale of industrial pot growing in Northern California. That’s where Silvaggio’s video comes in.

In a narrated version of the video for Mother Jones, Silvaggio suggests that the solution to the widespread environmental damage wreaked by industrial pot growers is to end the federal prohibition of marijuana, a sentiment shared by Gary Graham Hughes, executive director of the Arcata, Calif.-based Environmental Protection Information Center. “(Marijuana) is clearly something that's here to stay," he said.

“This vacuum that's created by the way the federal government continues with prohibition, it's making it very difficult to address the environmental issues."

Marshall Swearingen is an intern at High Country News.

Image courtesy California Department of Fish and Wildlife.