Project Description

The urban portion of the watershed contributes about 70% of the fine sediment that is delivered to Lake Tahoe. These fine particles significantly affect water clarity in this otherwise pristine lake. Current pollutant reduction strategies are targeting their removal through erosion control and stormwater treatment projects. The investment of significant financial resources to improve the Lake's clarity requires that our understanding of the sources, transport and potential for removal of these particles from urban stormwater be accelerated. The intent of this project is to add to our current, yet incomplete knowledge concerning fine particles. Specifically, this project will provide information to (1) help establish reliable, calibrated relationship(s) between turbidity, the mass of size fractionated suspended solids, and the number of <16 ?m micron particles in stormwater runoff, (2) provide details on mechanisms involved in the removal of fine particles in vegetated BMP treatment basins and (3) provide data on the efficiency of this type of commonly used BMP while giving recommendations for design characteristics to increase fine particle removal. The Lake Tahoe TMDL (Total Maximum Daily Load) program and associated efforts to improve lake clarity (e.g. EIP) will greatly benefit from increasing our understanding of fine sediment removal and how to measure success.