Client: Berkeley County, South Carolina Department of Transportation (SCDOT)
Location: Berkeley County, SC
In January 2013, Berkeley County (County) solicited proposals for coastal stream mitigation to support projects funded by the County’s One Cent Local Option Sales Tax. The ‘full-delivery mitigation’ solicitation, managed by the SCDOT, was only the second to be issued in the state of South Carolina and has allowed local municipalities and the SCDOT to contract for turn-key mitigation where mitigation credits were not readily available, expedite USACE permitting timelines, focus on core competencies (transportation infrastructure improvement), and transfer the development and risk of mitigation to the private mitigation sector.
The Cannon Creek Mitigation Site provides stream mitigation credits in the Cooper River watershed and Mid-Atlantic Coastal Plain. Cannon Creek was a degraded incised coastal plain stream system which provided limited habitat diversity. Nutrients and stormwater runoff were discharged directly into Cannon Creek and conveyed into the Cooper River; a 303d listed waterbody. The project restored 4,764 linear feet of Cannon Creek and its tributaries. Improved in-stream and terrestrial (riparian) habitats were provided, along with improved stream stability, reduced risk of sewer infrastructure encroachment, and improved hydrologic function. Nutrient and sediment reduction is being provided through vegetative buffering, cattle exclusion, and relocation of the stream away from the sanitary sewer line and residential backyards. Excavation of a new floodplain at a lower elevation allows for frequent floodplain inundation, nutrient filtration, and reduced loadings to the Cooper River. Construction was completed in 2015 and Wildlands is currently conducting five years of post-construction monitoring.