Sierra Colina Village
P. O. Box 129
Lake Tahoe, NV 89448

Planning for...
LEED* Green Certification
Energy Star Rating
Pedestrian & Bike Trails
All Fire Sprinklered Homes
Preserving Open Space
Moderate Income Homes

The Lake Tahoe Total Maximum Daily Load (TMDL) is the scientific analysis at the forefront of the effort to restore lake clarity. A “TMDL” identifies the maximum pollutant load a waterbody is able to assimilate while maintaining its water quality standards and supporting its designated beneficial uses. To date, the Lake Tahoe TMDL has involved research, investment by federal and state government, design of technologies to address Tahoe-specific issues, and inter-agency cooperation. (Master Comment F at page 2-250 of the Sierra Colina Final EIS).

The federal Clean Water Act (CWA) establishes water quality standards. Waters of the United States are assigned beneficial uses such as drinking water supply, water contact recreation, and aquatic life support according to the beneficial ways that these waters are used by people, animals, and the environment. One of the beneficial uses of Lake Tahoe is termed “recreation (water contact and non-water contact).” This beneficial use is also referred to as, “aesthetic enjoyment of Lake Tahoe clarity.” This aesthetic enjoyment is impaired by the declining clarity of the lake waters. When the water quality standards that describe a minimum requirement for a beneficial use are not being met, a TMDL is required by the CWA.

The Lahontan Regional Water Quality Control Board (Lahontan RWQCB) and Nevada Division of Environmental Protection (NDEP) are developing a sediment and nutrient TMDL. Findings to-date provide an understanding of the magnitude of reduction of fine sediment particles and nutrients (nitrogen and phosphorous) needed to achieve nearly 100 feet of clarity. TMDL findings serve as a valuable basis for focusing efforts to restore Lake Tahoe, using the most effective and cost-efficient mechanisms. The TMDL also helps to develop and prioritize research and monitoring efforts and focus resource management policy on results. Most importantly, the TMDL will define pollutant load reduction requirements for inclusion in permits and inter-agency agreements.

The Lake Tahoe TMDL strategy will likely be implemented by local, state, and federal regulatory and land management agencies and jurisdictions through their respective programs. The distribution of allocations (pollutant load reduction requirements) to these entities will be managed by Lahontan RWQCB for California and NDEP for Nevada. According to the TMDL guidelines, the sum of all Tahoe Basin allocations must result in attainment of the nearly 100-foot clarity standard over time. Allocations are expected to satisfy the principles of cost-effectiveness, equitability, public acceptance, and accountability (For further discussion, see Master Comment F at page 2-250 of the Sierra Colina Final EIS).

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