Surface Runoff

In developed watersheds with large impervious surface areas such as roads, driveways, and rooftops, stormwater runs over impervious surfaces, collecting pollutants such as sediment, nutrients, and oil and grease as it travels, enters the nearest storm drain or stream and ultimately ends up in Lake Tahoe. All storm drains eventually lead to Lake Tahoe. Runoff containing fine sediment and nutrients cloud the water and feed algal growth, which has led to over 30 feet of clarity loss since the 1960’s. Science shows that implementing Best Management Practices (BMPs) on new or existing development can improve Lake Tahoe’s water quality and clarity. BMPs are measures taken to minimize soil erosion and capture polluted water before it enters Lake Tahoe and are required on all new development and redevelopment projects in the Region.

Indicators

THRESHOLD CATEGORY REPORTING CATEGORY INDICATOR
THRESHOLD CATEGORY REPORTING CATEGORY INDICATOR

The threshold evaluation assigns a status to an indicator relative to the adopted standard. As shown on the icon legend below, the background color of the reporting icon communicates the indicator “status” or estimate of current condition. For numerical standards, the status of an indicator is classified into “better” or “worse” categories based on the percent divergence of the current indicator value from the standard or interim target. For most indicators, the current value is taken directly from the value recorded in the most recent year. In some cases, the average value calculated from all data collected during the evaluation period is used. When an average value is used, it is noted and explained on the indicator evaluation page for that specific evaluation year.  

Note: Thresholds reported as "Implemented" refer to thresholds that were adopted as policy guidance in the development of the Regional Plan. In these cases, the subject policies, ordinances, or environmental protections have been incorporated into the TRPA Regional Plan and TRPA Code of Ordinances.