Cabin Branch

Cabin Branch

ANNAPOLIS, MD

The Cabin Branch Stream Restoration project was designed to restore the headwaters of Saltworks Creek and treat highly polluted runoff from the adjacent shopping mall and warehouse store complex. It features three distinct prototype demonstrations for the Regenerative Design approach. First, a Legacy Sediment Removal End-of-Pipe restoration restored the upper 750 linear feet of stream into a system of cascades, riffles, and vegetated pools flowing through a valley ringed by fill and bisected by a filled utility right-of-way. In order to accommodate the fixed elevations of the existing culverts. U&A  removed thousands of cubic yards of sediment which provided the space to construct the riffles and pools at the appropriate elevations. The second part of the project was a retrofit of a Stormwater Dry Pond identified in the Anne Arundel County Watershed Implementation Plan (WIP) as in need of conversion to current practices. U&A raised the landscape (with the excavated material generated from the legacy sediment removal) to capture water from the adjacent parking lot and channel it through 490 linear feet of pools, cascades, and seeps before flowing into the stream.

Third, a Sand Seepage RSC raised the invert of the incised stream channel and established riffles and berms to reconnect 500 linear feet of the stream to the floodplain. The total project extends 1,740 linear feet. In order to minimize tree removal and keep the forest intact, U&A constructed gravel seeps rather than over-excavating the area. This allowed us to remove only four trees on this entire project, two of which were successfully transplanted to new locations on the project site.

This stream restoration is a showcase for the Regenerative Stream Channel (RSC) approach, which integrates ecosystem restoration into the project. Through the installation of a system of cobble riffles, berms, seepage wetlands, shallow pools, and native plants, we restore stream and wetland function, reconnect the stream to the floodplain, and restore historic plant communities. Restoration focused on three areas: 1) end of pipe restoration, 2) retrofit of an outdated 1970’s Stormwater Dry Pond, and 3) Creation of Sand Seepage RSC below the filled right-of-way The completed project will provide habitat for resident fish and amphibians, improve water quality downstream, reduce nutrient and sediment loads from the Annapolis Mall, restore base flow to the stream, and re-introduce native plant species into the forested wetland and valley shoulders.

Severn River Keeper Collaboration Project