Description

The Town partnered with CDM Smith to undergo a comprehensive drainage study of the entire Hobcaw Point Subdivision in 2019. The study area is approximately 295 acres, bound on the North by Hobcaw Creek, on the South by Molasses Creek, on the West by the Wando River, and on the East by the ION Subdivision. The Town identified Hobcaw Point subdivision as an area whose aging drainage infrastructure is in need of repair, replacement, or reform as a result of development, changes in engineering practices, and challenges to regular maintenance within the area.

The study area was broken into 34 drainage basins or areas of land draining to a common point. The level of service (LOS) for each basin was determined by comparing system capacity to projected peak runoff during a storm. A priority analysis was performed and basins ranked based on drainage area acreage, number of parcels, pipe LOS, infrastructure/flooding service requests, number of FEMA flood claims, number of redevelopment permits, closed basin acreage, and system coverage within each basin. The study results determined 6 priority basins to receive improvements: East Molasses, Isaw, West Molasses, Muirhead, Sampa, and Seewee Circle.

The Town has partnered with RK&K to develop construction documents for selected priority basins. The proposed system will provide a ten-year storm level of service. Construction will include installing new pipes, upsizing old pipes, re-establishment of swales, and incorporating low impact development (LID) stormwater management practices. As part of this process, some trees within the right-of-way and drainage easements will have to be removed. The original drainage systems incorporated shallow roadside swales which, over time, have been filled in. In many cases, homeowners added street parking in these areas. As part of this project, many of the swales will be restored within the right-of-way. It is incumbent upon us as citizens collectively benefiting from a properly functioning drainage system to maintain these areas.

Resources

View the Hobcaw Point Subdivision Drainage Study Report

Funding

FEMA Hazard Mitigation Grant Program (HMGP) Award administered by the South Carolina Emergency Management Division (SCEMD)

South Carolina Office of Resilience (SCOR) Community Development Block Grant - Mitigation (CDBG-MIT) Agreement

Schedule

• Permits Submitted October 2023
• Bid Advertisement Summer 2023
• Notice to Proceed Fall 2024
• In Operation Fall 2025

Cost

$3.3M

Contact

Marissa Noble, PE

• Ph: (843) 856 - 3080 
• Email: MNoble@tompsc.com