California has seen a recent boom in marijuana farms, mostly on private lands but also illegal grows on public lands such as national forests. Hard data are hard to come by for this crop, which is mostly grown in the shadows. But California Department of Fish and Wildlife officials estimate that production on public lands has increased by 55 to 100 percent in ecologically fragile north coast watersheds over the past five years alone. This surge is having a decidedly unhealthy effect on some of California’s rivers and streams. The situation is heating up as many of the state’s waterways are at all-time lows and some at-risk fisheries nearing collapse.
A study of four northwestern streams by the California Department of Fish and Wildlife (CDFW) found that marijuana plants consumed 20-30% of streamflow during the dry summer low-flow season—a crucial period for salmon and other species – as well as marijuana cultivation. Illegal marijuana growing also can bring a host of other environmental problems, from polluted runoff to habitat damage from improper road construction.
Peter Moyle, a fisheries expert with UC Davis and a member of the PPIC Water Policy Center research network, says, “All of these operations are taking water directly from streams, sucking away water from endangered Coho salmon, steelhead, tailed frogs, and other stream-dwellers, while damaging the banks of the streams. These diversions require permits—both from CDFW for stream alteration and from the State Water Board for diverting water—but few such permits seem to have been issued.”
Last year, Governor Jerry Brown marked $3.3 million in his budget proposal for enforcing pot growing rules in an effort to protect both the water supply and endangered species affected by growers.
Various state and local efforts are underway. The multi-agency Cannabis Pilot Project will enforce environmental protections in cannabis cultivation. The state’s Fish and Wildlife Watershed Enforcement Team inspects farms and seeks to permit them and bring them into compliance, but the understaffed team has been able to visit only a tiny portion of the state’s farms. New permitting processes to address illegal water diversions are in the works at the State Water Resources Control Board, but funding for compliance will be an issue. A recent a senate hearing called for a crackdown on illegal water diversions by marijuana growers.
In addition to highlighting the need for better regulation on the ground, the water impacts of marijuana growing are an example of the need for targeted and reliable sources of funding to address California’s environmental challenges. Currently, none of the tax revenue from California’s nearly $1 billion-a-year medical marijuana market is allocated for environmental protection.
Next year, Californians will likely be asked to vote on a ballot initiative to legalize possession of marijuana for recreational uses, as has been done in four other states and the District of Columbia. The potential ballot initiative provides an important opportunity to address a number of policy trade-offs, including the issue of how to pay for the environmental impacts of marijuana legalization.