Marijuana Cultivation Poses Environmental Threat to Dwindling Salmon Populations

The Northern California marijuana industry is booming, but issues with water consumption and downstream pollution produced by the large-scale cultivation of marijuana are threatening populations of salmon already on the brink of extinction.

2 minute read

January 14, 2014, 11:00 AM PST

By James Brasuell @CasualBrasuell


The environmental impacts of the recent boom in marijuana growing operations have prompted calls for stronger regulation of the business of cultivating marijuana. At stake is the protection of multiple species of salmon, which has dwindled to the brink of extinction along the North Coast of California. “As many as a half-million Chinook salmon once spawned in the Eel River each year. By the 1950s, the fish were almost gone. Since then, the population has slightly rebounded, and several thousand Chinook now return to the Eel annually,” reports Alastair Brand. Dave Bitts, a Humboldt County commercial fisherman and the president of the Pacific Coast Federation of Fishermen's Associations is quoted describing the importance of maintaining watersheds as habitat for salmon: "There is no salmon-bearing watershed at this point that we can afford to sacrifice."

The impacts of marijuana cultivation on watersheds are at least twofold. First, there is the process’s water supply requirements. According to Brand, “Growers of marijuana often withdraw water directly from small streams and use up to six gallons per day per plant during the summer growing season.” Growers might be cultivating as many as 20,000 or 30,000 plants in one watershed.

The effluents produced by marijuana growers poses another risk: “Fertilizers that drain into rivers can cause floating carpets of algae to grow in the water. When these mats begin to decay, the breakdown process steals oxygen from the water, suffocating fish."

Monday, January 13, 2014 in NPR The Salt

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

April 30, 2025 - Diana Ionescu

Close-up on Canadian flag with Canada Parliament building blurred in background.

Canada vs. Kamala: Whose Liberal Housing Platform Comes Out on Top?

As Canada votes for a new Prime Minister, what can America learn from the leading liberal candidate of its neighbor to the north?

April 28, 2025 - Benjamin Schneider

Hot air balloons rise over Downtown Boise with the State Capitol building visible amidst the high rises.

The Five Most-Changed American Cities

A ranking of population change, home values, and jobs highlights the nation’s most dynamic and most stagnant regions.

April 23, 2025 - GoodMigrations

Sleeping in Public

Housing, Supportive Service Providers Brace for Federal Cuts

Organizations that provide housing assistance are tightening their purse strings and making plans for maintaining operations if federal funding dries up.

45 minutes ago - KSL

Conductor walks down platform next to Amtrak train at station in San Jose, California.

Op-Ed: Why an Effective Passenger Rail Network Needs Government Involvement

An outdated rail network that privileges freight won’t be fixed by privatizing Amtrak.

1 hour ago - Streetsblog USA

Aerial view of flooding during Hurricane Helene in North Carolina.

‘Quality Work, Fast’: NC Gears up for Homebuilding After Helene, Trying to Avoid Past Pitfalls

The state will field bids to demolish, repair and rebuild homes in the mountains. After struggles in eastern NC, officials aim to chart a different course.

2 hours ago - NC Newsline

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.