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Environmental Analysis + Timeline



The lead agencies received thousands of comments about the Tahoe Keys Lagoons Aquatic Weed Control Methods Test draft environmental document. The agencies reviewed all comments, finalized the environmental document, conducted a peer review of the proposed project’s monitoring program, and coordinated with myriad agencies and partners throughout the basin.

Lahontan Regional Water Quality Control Board released a Draft National Pollutant Discharge Elimination System permit with an Antidegradation Analysis in fall 2021 with adequate time for the public to provide comments and feedback.

The Final Environmental Impact Report/Environmental Impact Statement was released prior to the lead agencies considering the document for adoption.

The Tahoe Keys Lagoons Aquatic Weed Control Methods Test was approved by both lead agencies in January 2022:



close up view of curlyleaf pondweedTKPOA submitted the Control Methods Test application proposing the use of targeted herbicides as one control method to test in combination with other methods, including Ultraviolet Light tests, to reduce and control the abundant growth of non-native and nuisance aquatic weeds that are compromising the water quality and degrading the beneficial uses of the Tahoe Keys lagoons, as well as threatening the future ecosystem and water quality of Lake Tahoe.

The environmental analysis team assembled a team of independent experts who collected and analyzed data to understand the impacts of the proposed tests, along with alternate management options during 2019 – 2021.

The final environmental analysis determined the use of U.S. Environmental Protection Agency (EPA) and Department of Pesticide Regulation (DPR) approved herbicides can meet the strict environmental standards of Lake Tahoe’s classification as a Tier Three, Outstanding National Resource Water.

A collaborative team of scientists and analysts continues to meet regularly to discuss data collected and next steps.  TRPA continues to oversee monitoring of the tests.