Reduce Fine Sediment Particle Load
This indicator measures the amount of fine sediment load reduction achieved in the Lake Tahoe Region. Sediment (particularly fine sediment) delivered to Lake Tahoe is known to directly affect the transparency of Lake Tahoe. Excessive amounts of fine sediment are the leading cause of impairment in streams and lakes of the United States. Landscape disturbances including, but not limited to, impervious road and parking lot surfaces, residential and commercial development, wildfire, and the degradation of stream environment zones, can contribute to sediment inputs to the lake and its tributaries. Fine sediment reductions are monitored by partners through the Lake Tahoe Total Maximum Daily Load (TMDL) program.
Status
Evaluation Map
Lake Clarity Tracker Projects
2019 Evaluation
- Status
- Considerably Better Than Target
- Trend
- Moderate Improvement
- Confidence
- Moderate
Applicable Standard
WQ34) Reduce fine sediment particle (inorganic particle size < 16 micrometers in diameter) load to achieve long-term pelagic water quality standards (WQ1 and WQ2).
Key Points
- In 2019, TMDL implementors (CalTrans, CLST, Douglas, El Dorado, NDOT, Placer, Washoe) exceeded their load reduction targets and collectively reduced fine sediment particle load by 19.7 percent, preventing roughly 477,000 lbs/yr from reaching the lake (30 percent greater than the target).
- In 2019, approximately 7,500 miles of streets were swept using high-performance sweepers, 29 non-compliant wood stoves were removed or replaced, and nearly seven miles of pedestrian and bicycle routes were constructed. These projects all help to reduce fine sediment particle loads.
- At the September 2020 meeting of the Threshold Update Initiative Stakeholder Working Group, consistent with guidance from the Tahoe Science Advisory Group, the water quality standards related to load reduction were recommended to be removed as threshold standards and retained as Environmental Improvement Program performance measures.
Delivering and Measuring Success
EIP Indicators
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Miles of Street Sweeping
Since 2009, EIP partners have swept more than 68,000 miles of roadway in the Tahoe Region collecting fine sediment particles before they reach Lake Tahoe.
Lake Clarity Indicators
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Fine Sediment Load Reduction
TMDL urban implementing partners have acheived greater than total fine sediment particle targets required by permits and agreements.
Monitoring Programs
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Regional Stormwater Monitoring
The Regional Stormwater Monitoring Program measures pollutants in urban runoff to evaluate the effectiveness of pollutant control measures and track and report monitoring findings.