Urban Stream Restoration
Recent research has shown differences in nutrient and sediment delivery rates between healthy, degraded and restored urban streams. In particular, urban streams experience high rates of channel erosion that deliver high nutrient and sediment loads. For example, the current version of the CBWM utilizes a strong empirical relationship between impervious cover and sediment delivery in urban watersheds (Langland and Cronin, 2003). The CBWM predicts sediment loads of 100 lbs/acre occur in watersheds with the least development, but this climbs to nearly 700 lbs/acre for the most intensely developed watersheds.
In early 2012, an Expert Panel was convened to review all of the available science on the nutrient and sediment removal performance associated with qualifying urban stream restoration projects in relation to those generated by degraded urban stream channels. The final recommendations of the urban stream restoration expert panel were approved by the Water Quality Goal Implementation Team (WQGIT) on May 13, 2013.
Because of the complexity of the stream restoration protocols, the Expert Panel decided there would be a “Test Drive Period” so that states and localities could “test” the protocols on actual projects. The results would identify sections of the reports that require clarification or editing to improve the protocols. The revised recommendations were approved by the Urban Stormwater Workgroup January 21, 2014 and more recently by the Water Quality GIT in August 2014. They can be downloaded below.
Also, don’t forget to check out our newly developed Urban Stream Restoration “Fact Sheet” which breaks down the practice and the expert panel recommendations into delicious bite-size pieces…yum, yum, enjoy!