The California Department of Fish and Wildlife (CDFW) is investigating the potential environmental impacts of water diversions associated with cannabis cultivation in three streams in the upper Mattole River watershed in Humboldt County.

The study is comparing hydrological and biological parameters such as stream flow, water temperature, dissolved oxygen levels, aquatic insect community composition, and fish movement in streams with and without cannabis cultivation.

This pilot research project could support efforts to establish sustainable levels of cannabis cultivation in sensitive watersheds on the North Coast and lead to the initiation of similar studies throughout the state. 

The study findings are expected to be published on the CDFW website in the fall of 2019

“Research is an important tool in understanding the impacts of cannabis cultivation on the environment,” said Joshua Grover, CDFW Cannabis Program Director. “CDFW supports the legalized cannabis market and works with cultivators to limit environmental impacts. Using a science-based approach will help our staff make informed management decisions on sustainable levels of cannabis cultivation.”

More details on the pilot study can be found in the January/February issue of Outdoor California with an article titled, “Cultivating Cooperation.” To read the article, please visit: www.wildlife.ca.gov/Conservation/Cannabis/News and click on the link. Additional details about the study can be found here: www.wildlife.ca.gov/Conservation/Cannabis#53534624-environment.

Cannabis cultivators with questions can email CDFW [email protected].

CDFW encourages cannabis cultivators to obtain all necessary state licenses and county permits, as well as implement best management practices to reduce environmental impacts. Following these recommended actions can help cultivators avoid common pitfalls that may lead to enforcement actions.