Action Needed to Keep Tahoe Blue

Published in the Reno Gazette Journal.

This opinion column was submitted by Darcie Goodman Collins, Ph.D., CEO of the League to Save Lake Tahoe.

For many, Lake Tahoe is a refuge. It’s a place to escape, unwind and recharge. Yet the recent Lake Tahoe Summit made one thing crystal-clear: to keep Tahoe blue, we can’t afford to take a vacation from protecting the lake we love. When it comes to tackling Tahoe’s aquatic invasive weed problem, inaction could spell disaster.

Aquatic invasive weeds are underwater plants that don’t naturally occur in the lake. Unintentionally introduced to Tahoe decades ago, they threaten to destroy Lake Tahoe’s native ecology, pristine water quality and world-famous clarity, while also impacting our enjoyment of the lake we love.

For more than eight years, the League to Save Lake Tahoe has been deeply involved in efforts to control Tahoe’s aquatic weed problem where it’s most severe: the Tahoe Keys. With more than 90% of its 172 acres of lagoons infested, this planned community developed on the South Shore in the 1960s is ground zero for the invasive weed problem in Lake Tahoe. And the infestation is spreading. More than 100 acres of the lake itself are now infested with weeds.

The tools on hand are not sufficient to treat a problem as big and complex as in the Keys. Testing innovative technologies and new combinations of treatments — including UV light, laminar flow aeration and targeted herbicides — will show us how to overcome the challenge. Crucially, the new tools must not only be effective, they must be safe for the Lake Tahoe environment and everyone who enjoys it. 

Enter the proposed Tahoe Keys Lagoons Aquatic Weed Control Methods Test. As its name suggests, the test is not a full-scale project; it is a highly regulated, three-year trial of all available methods and combinations of treatments. At the heart of this proposal is a novel approach: a one-time test application of EPA-approved herbicides at low concentrations in dead-end lagoons to knock down the weeds, followed by nonchemical treatments to keep the population in check for the long term. If proven successful, Tahoe can continue to serve as a global model for sustainable environmental protections.

The League to Save Lake Tahoe is concerned about the potential use of herbicides at the Lake. For 63 years, we have defended Big Blue from all threats to its famously clear waters — and aquatic invasive weeds pose the greatest ecological threat today. If science shows the test can be conducted safely, we must try. Failing to take control of the problem now puts all of Lake Tahoe at even greater risk.

Currently, the application for the test is undergoing a rigorous scientific review and public consultation process, including an “antidegradation analysis” to assess even the slightest risk from limited herbicide use. The process has produced one of the most extensive environmental impact reports/statements ever compiled for a small-scale testing project. It includes multiple layers of protections, mitigations and monitoring to protect human and environmental health.

While we await the completion of the environmental review, one thing is as clear as Lake Tahoe’s waters: if we do nothing, the problem will get worse. To keep Tahoe blue, we must tackle the invasive weeds problem in the Tahoe Keys now.

For more information, visit TahoeKeysWeeds.org.

Read the story at the Reno Gazette Journal.