Media Releases

League to contribute portion of funds to study solutions to aquatic invasive weeds at the Tahoe Keys

March 2, 2017

The League to Save Lake Tahoe has offered to fund a portion of a study of methods that might finally address a decades-old infestation of aquatic invasive plants in the lagoons of the Tahoe Keys, adjacent to Lake Tahoe.

Aquatic invasive plants in the lagoons of the Tahoe Keys are growing out of control and are spreading to the west, east and north shores of Lake Tahoe. Unchecked, they threaten to destroy Lake Tahoe’s ecology, pristine water quality and famous clarity. The League has offered to support a scientific test, which would be conducted in a small section of the Keys lagoons — those furthest from the Lake and to be separated by an impermeable barrier — to determine whether a combination of mechanical and chemical treatments can bring the infestation under control before more of the plants spread to the Lake.

The Tahoe Keys Property Owners Association has recently submitted an application to state regulators for an integrated control methods test that includes trials of both chemical and nonchemical methods. Soon, the property owners will vote on whether to pay for the bulk of the study, approximately $2.7 million, via a homeowner assessment. Subject to the proposal’s approval by state authorities and the necessary financial commitment by the homeowners, the League would contribute up to $100,000 over four years towards the cost of the study. The contribution would also be contingent on ongoing environmental monitoring. A special campaign to raise these funds would be initiated by the League this summer. Residents and visitors committed to preventing the spread of aquatic invasive species in Lake Tahoe are encouraged to reach out to the League to support this effort.

“Aquatic herbicides have never been used in Lake Tahoe,” said Jesse Patterson, the League’s deputy director. “The League is taking this difficult decision very seriously. Ultimately, we are following the best available science, which tells us that the status quo poses an extraordinary threat to Lake Tahoe as we know it. Through these trials, we’ll be able to test multiple control methods. The best science suggests that herbicides need to be part of the solution at the Keys. What specifically that looks like is yet to be determined. It must be done safely, and in a manner that does not threaten the rest of Lake Tahoe.”

If the Property Owners Association moves forward, the test would only be conducted in the Keys lagoons, and only after a public environmental review process. Testing of mechanical control methods would begin in 2017, with parallel tests using both mechanical and chemical methods to start in 2018 at the earliest. No chemical methods would be tested in Lake Tahoe itself. In a scenario where the test results demonstrate a viable role for chemical herbicides to control the Keys infestation, further environmental review and public input would be conducted before additional chemical use could be permitted within the Keys lagoons.

“The League will remain heavily involved in the adaptive management and review of the plan, just as we have for the past few years,” said Patterson. “At every step, we’ll continue to monitor the process and remain a watchdog for the best interests of Lake Tahoe.”

For more information, contact League staff at

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