Photo Courtesy of Butte County, Calif.

Unregulated marijuana cultivation, such as in California's Upper Central Valley, poses a threat to watersheds because of deforestation, watercourse diversion and uncontrolled runoff of pollutants.

California officials are considering policies to protect the state's water resources from the growing problems associated with legal marijuana cultivation. The proliferation of farms, both legal and illegal, has exploded in the state due to the loosening of legal prohibitions on the sale of marijuana.

After initially declining to place its agency inspectors at risk, the Central Valley Regional Water Quality Control Board approved allowing its field personnel to accompany law enforcement to inspect marijuana farms. The sparsely populated regions of the western flank of the Sierra Nevada range have attracted growers who operate with little regard for the safety of the streams and groundwater.

"We will be looking at water-quality impacts, grading adjustments, watercourse diversion and pollutants," said Clint Snyder, the water district official overseeing the initiative. "We will use our standard set of enforcement tools to go after the landowners."

With the 1996 passage of Proposition 215, which legalized the use of medical marijuana in California, growing the plant technically became legal at the state level, although it remains subject to the federal Controlled Substances Act.

Since then, the cultivation of marijuana has boomed, especially with the proliferation of industrialized marijuana farms operated by drug cartels. Typically located on public lands, these operations use construction equipment and industrial fertilizers to maximize production. They often cover several acres and involve as many as 100,000 plants.

Today, marijuana is believed to be the state's biggest cash crop, with an annual harvest worth at least $14 billion. Outside of law enforcement, there is limited legal recourse to control the growing environmental impact of marijuana cultivation, which includes deforestation, watercourse diversions and, entering the watershed, unrestrained runoff containing fertilizers, herbicides and pesticides.

Earlier this year, Bill Connelly, Butte County Board of Supervisors chairman, requested that the Central Valley water board assist local law enforcement overseeing water-pollution regulations with regard to the marijuana farms. The board agreed it is a serious issue but declined to provide staff, citing safety concerns.

The exchange promoted the creation of the task force at the direction of Assemblyman Dan Logue (R-Loma Rica). The group includes representatives of the Central Valley Regional Water Quality Control Board, local sheriff's offices, the Dept. of Fish and Wildlife, and the office of Gov. Jerry Brown (D).

The task force struck the agreement that paved the way for the water board to approve allowing its inspectors to examine marijuana farms for violations of water-pollution rules. Snyder says they expect to begin inspections in the next few weeks.

It isn't an isolated case. The North Coast Regional Water Quality Control Board currently is developing a category for medicinal marijuana as part of its Agricultural Lands Discharge Program that will provide authorization for discharges of waste if water-quality protection requirements are met.

Logue said the next step would be to align state laws regulating marijuana cultivation with existing statutes covering timber and agricultural crops.

"Right now, there is nothing [within] state government on how to address the impact to the environment from these farms," Logue said. "Our next step would have to be legislation."