Environmental Incentives
Environmental Incentives
Emerald Bay, Lake Tahoe

Water, Adaptive Management

Lake Tahoe TMDL Management System

Click here to visit the TMDL Online Interface


South Lake Tahoe, CA


The Challenge

Lake Tahoe is famous for its remarkable clarity and striking blue color. As the largest alpine lake and second deepest in North America, it is designated an Outstanding National Resource Water by the state of California and a “water of extraordinary ecological or aesthetic value” by the state of Nevada. The Lake Tahoe Basin is a destination for millions of visitors annually and is home to approximately 60,000 year-round residents.

Between 1968 and 2000, approximately one-third of Lake Tahoe’s unique clarity was lost. To address this issue, the Lahontan Regional Water Quality Control Board (Lahontan Water Board) and Nevada Division of Environmental Protection (NDEP) collaborated to develop the Lake Tahoe TMDL. The Lake Tahoe TMDL is a science-based plan to better understand the causes of the loss in lake clarity, determine how much pollution needs to be reduced to reinstate historic clarity, and develop a workable, cost-effective implementation strategy.

The TMDL program estimates it will take at least 65 years of targeted effort and investment to restore clarity to historic levels. Over this long period program implementation will be influenced by a variety of factors, including shifting political and economic environments, new scientific findings, stakeholder input, and unforeseen conditions caused by climatic, geologic or wildfire events. In the face of the extended timelines and changing circumstances, it is essential the TMDL Program remain flexible and adaptable.

The Solution

Environmental Incentives worked closely with Lahontan and NDEP, and in partnership with Northwest Hydraulic Consultants, 2NDNATURE, and Sitka Technology Group to design, test and launch the Lake Tahoe TMDL Mangement System. The Management System effectively establishes the operational practices that guide program management into the future by providing the means to consistently track and report program accomplishments and identify and respond to challenges, relevant research findings, and technical information that warrant programmatic or policy adjustments.

The Outcome

The TMDL Management System is now being fully operated by staff at Lahontan and NDEP. It represents one of the most robust and significant environmental adaptive management efforts in the country, and it continues to streamline TMDL Program operations. Agency staff have used the TMDL Management System to coordinate effective water quality actions and generate input from stakeholders in the Tahoe Basin. While Lake Tahoe’s clarity continues to fluctuate year after year from a variety of environmental factors, those working to improve clarity over the long-run have the tools they need to make this possible.

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