Infiltration BMP Design and Maintenance Study

Scientific Publications

Structural BMP

Prepared by 2NDNATURE and Northwest Hydraulic Consultants for Tahoe Regional Planning Agency.

Executive Summary excerpt

Infiltration BMPs are installed throughout the Tahoe Basin to meet regulatory requirements to retain and infiltrate the runoff volume generated by a 20‐year, 1‐hour storm from all impervious surfaces on a parcel.   When this regulation is successfully applied, the hydrologic impacts of impervious surfaces and pollutant loading via stormwater runoff can be significantly reduced. However, sustaining the hydrologic and water quality benefits of infiltration BMP implementation requires regular maintenance. Previous studies have identified a lack of BMP maintenance in the Tahoe Basin as a common occurrence, resulting in infiltration BMP performance declines and failures (DRI 2004, 2NDNATURE 2006, 2009, and 2010a). Funded by the Tahoe Regional Planning Agency (TRPA), this research relies upon field surveys and laboratory experiments to improve our understanding regarding the timing and mechanics of infiltration BMP performance declines. The findings from this research are intended to guide a series of recommended improvements to infiltration BMP design and maintenance guidelines, including those within the TRPA BMP Handbook (TRPA 2012).