Save Lake Tahoe from invasive weeds and herbicides (Opinion) |

Save Lake Tahoe from invasive weeds and herbicides (Opinion)

Carolyn Willette
Guest column

More than 50 years ago, developers committed one of the greatest injuries to Lake Tahoe — dredging the lake’s largest natural wetland to build the Tahoe Keys development — 1,500 homes with canals for private boaters.

Today, local powers are considering making that injury much worse.

The Tahoe Keys artificial lagoons are an ecological disaster, because they destroyed the lake’s natural filtering system (a healthy wetland) that purified the largest inflow. The lagoons are now rife with invasive aquatic weeds (Eurasian milfoil and curly leaf pondweed) and dangerous algae blooms. Signs line the lagoons, warning people of the dangerous waters caused by toxic algal blooms.

Ignoring these dangers, the Tahoe Regional Planning Agency and the Lahontan Regional Water Quality Control Board are moving forward with a reckless proposal by the Tahoe Keys Property Owners Association to treat the invasive weeds with deadly herbicides. And for what? To allow boaters at this private development to boat from their backyards to the lake.

Chemical herbicides have never been allowed in Lake Tahoe before, because the Environmental Protection Agency classifies it as a Tier-3 Outstanding Natural Resource Water that cannot be degraded. The above agencies admit using herbicides in Lake Tahoe will never eliminate the weeds; it will only “manage” them so boats can pass. Continued use of dangerous chemicals will be necessary in perpetuity to keep the weeds under control. To add insult to injury, taxpayers will pay tens of millions of dollars for a treatment that will never work, to suit the convenience of Tahoe Keys’ boat owners.

Earlier this summer, the UC Davis Tahoe Environmental Research Center reported the lake’s fabled clarity declined by more than 8 feet in 2019. This measure demonstrates that we need to take more aggressive action to save our favorite lake from climate change and the impacts of human development.

Now is our chance to demand long-term solutions that actually benefit the health, beauty, and water quality of the lake, as well as the everyone who lives in and visits the Tahoe basin, not just the boating homeowners of the Keys.

It’s time to heal Lake Tahoe by addressing the underlying cause of the Keys’ weeds and algae infestations by restoring the lake’s own water-purifying systems, the natural wetlands that existed before the Keys were constructed.

Restoring the Keys lagoons to a healthy functioning wetland would solve the weed problem by eliminating the shallow, warm canals that are the weeds’ habitat. Without weeds, we would need no herbicides to control them. Restoring the wetland would immediately improve the water quality and clarity of our cherished lake by filtering nutrients, sediments and pollution from the largest inflow tributary. Done well, it could enhance the Tahoe Basin’s health, beauty, tourism economy, and quality of life, while saving tens of millions of taxpayer dollars.

Replacing the Keys’ canals and lagoons with natural wetland habitat (and perhaps some boardwalks or hiking trails) would restore wildlife habitat and natural beauty, while enhancing quality of life, opportunities for outdoor recreation, and property values.

Proposing to treat these weeds with herbicides is like trying to put a bandaid on a severed artery. The Tahoe Keys lagoons never should have happened. But now that they exist, it’s time to do the most effective and responsible thing by healing the damage they continue to inflict on the lake and everyone who lives and visits the region by removing the canals and restoring them to natural wetlands. Attempting herbicide treatment only adds expense, injury and cost, without solving the problem.

Nature has proven time and again, if we put the pieces back, natural systems will return and they will begin filtering and purifying the waters that feed Lake Tahoe. Wetland restoration has been a success in countless places around the world. If we really want to Keep Tahoe Blue, it’s time to restore the Keys lagoons.

Public comments on the herbicide proposal are being accepted through Sept. 3. If we do not reject this irresponsible proposal now, Lake Tahoe will continue to decline because we failed to address problems the development created decades ago.

The Draft Environmental Impact Statement and Environmental Impact Report, “Tahoe Keys Lagoons Aquatic Weed Control Methods Test” may be found here.

More about Sierra Club’s concerns with the herbicide proposal can be found here.

Carolyn Willette is the chair of the Sierra Club Tahoe Area Group and longtime Tahoe City resident.

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