Illegal marijuana cultivation is devastating California’s public lands
Scattered throughout California’s public forests, authorities found 315,000 feet of plastic hose, 19,000 pounds of fertilizer and 180,000 pounds of trash on more than 300 illegal marijuana plantations in 2012 alone.
The tally comes from a new video by the U.S. Forest Service, describing the extensive and alarming damage caused by “trespass grows” hidden within the state’s public forested land. According to the video, the nation’s high demand for weed and paradoxical policies are exacting an “overwhelming” price on the environment, to the point where trespass grow investigations now comprise the bulk of Forest Service law enforcement work in the region, which includes California, Hawaii and the Pacific Islands.
But for a moment, put aside the fact that the crop in question is marijuana. For Rick Fleming, director of the High Sierra Volunteer Trail Crew and a devoted trespass grow cleanup partner in the Sierra region featured in the film, it might as well be illegal corn or strawberries.

“They’re killing our animals, trashing our forest and destroying our water supply,” Fleming said of the illegal growers. “It’s not so much a political issue as it is just trying to preserve public lands.”
Since 2008, Fleming has been organizing volunteer crews to work with the Forest Service and local law enforcement to clean up illegal grow sites. In 2013, the Forest Service and law enforcement officials removed nearly one million marijuana plants across hundreds of sites in California. “Sometimes it’s 10,000 plants (at a site). Sometimes it’s 50 plants,” he said. “That doesn’t matter so much for us. What matters is the infrastructure that’s left,” like makeshift reservoirs filled with diverted water from streams.
But for Fleming’s volunteer cleanup crews, the most remarkable thing is always “just how much trash – tons and tons of trash.” Among the waste typically hauled out: tents, sleeping bags, stoves, propane tanks, clothing, food packaging, even discarded weapons.

The thousands of pounds of herbicides and pesticides used by trespass growers pose another threat; most of them are applied in dangerously high doses, and some of them have even been banned in this country. California’s Eastern District U.S. Attorney Benjamin Wagner notes that his office is “increasingly charging marijuana growers not only with drug crimes, but with environmental crimes,” including dozens of indictments of trespass growers on public lands in 2012 and 2013.
Mourad Gabriel, wildlife pathologist and another trespass grow cleanup expert in the film, has been tracking the harmful effects of some of the toxins on Pacific fishers, small carnivorous mammals already being considered for the endangered species list now being pushed to the edge by pesticide poisoning.
And what about those hundreds of thousands of feet of hose? In a state plagued by drought, trespass growers illegally obstruct and divert water, sometimes from miles away. At about 6 gallons of water per plant per day over 150 watering days, a trespass grow site with 10,000 plants diverts 60,000 gallons of water per day, or 9 million gallons in a season. Herbicides and pesticides added to irrigation water seep into the ground and back into the local water supply, causing everything from algal blooms to total ecosystem destruction. In the coho salmon habitat of Humboldt County’s Mattole watershed, hundreds of trespass grow sites threaten to undo millions of dollars of habitat preservation efforts.