Stream restoration as a BMP: Development of a national performance database and crediting guidance

The International Stormwater Best Management Practice (BMP) Database (www.bmpdatabase.org) was recently expanded to include stream restoration practices. The new Stream Restoration Database (SRDB) is intended to help support stream restoration practice selection and design efforts, water quality crediting programs, and performance evaluations. Based on a literature review and assessment of the data contained in the first release of the SRDB (SRDB 1.0), the water quality benefits of various stream restoration practices can be illustrated, but significant data gaps exist that currently preclude statistically robust analyses. Concurrent with the development of the SRDB, a Stream Restoration Crediting Guidance was also developed. This Crediting Guidance provides a general technical framework for quantifying the water quality benefits of four practices with a focus on sediment and nutrients: stream stabilization, riparian buffers, in-stream enhancement, and floodplain reconnection. General technical considerations and challenges for developing stream restoration credits are discussed along with guidance for credit development.