The purpose of this project was to provide treatment for unpermitted impervious surfaces in the Stevens Brook watershed and provide flood control and slow erosive velocities of runoff entering Rugg Brook. Ruggiano Engineering worked with the Town and City of St. Albans, VT DEC Stormwater Section, and Vermont Agency of Transportation in supervising construction activities and preparing an Erosion Prevention and Sediment Control Plan.
This project involved the improvement of the existing diversion structure connecting Stevens and Rugg Brooks in St. Albans, Vermont. This structure is a man-made flood control device, constructed in the mid 1970’s, that diverts stormwater flows from Stevens Brook to Rugg Brook during larger storm events. In order to improve the structure’s performance, the Town of St. Albans proposed to construct a series of sediment and flow attenuating practices to ensure the flow entering Rugg Brook is treated to the maximum extent practicable. Ruggiano Engineering supervised principal work items for this project including: (1) modification of the Stevens Brook weir into a rip rap weir, (2) construction of sediment traps, and (3) construction of an extended detention basin.
Removal efficiency of the weir with respect to Stevens Brook is 100%, since the diversion structure removes the runoff from the receiving water. Annual sediment removal of Stevens Brook is estimated to be 9.63 tons. The extended-detention structure will also significantly reduce the in-stream erosion and sediment loading for Rugg Brook. Annual sediment removal from Rugg Brook is estimated to be 7.70 tons.
