DESCRIPTION: The Shell Point drainage basin area is geographically located on Port Royal Island within Beaufort County, SC. Through the period of 3/8/2017 to 2/5/2020, Beaufort County received over 49 flooding complaints from residents that live within the Shell Point drainage basin. The drainage basin encompasses approximately 1.3 square miles and features single-family residential, multi-family residential, and commercial land uses. Flooding complaints include ditches, streets, and yards to the extent that residents are unable to leave their homes due to streets that are not passable during smaller more frequent as well as larger storm events. A preliminary drainage study (by others) identified 12 areas of proposed improvements which include approximately 41,163 LF of right of way ditch restoration, 4,372 LF of culvert cleaning, 6,990 LF of channel restoration, and 985 LF of stormwater management system improvements.

J. Bragg Consulting (JBC) was tasked with providing all aspects of program delivery including, but not limited to, program/project management, public outreach, hydrologic and hydraulic analysis using PCSWMM, HY-8 and the SCDOT Unit Hydrograph (UH) Hydrology Method, management of 7 subconsultants, design for both SCDOT and Beaufort County stormwater management systems, stormwater management system condition assessment, and environmental permitting through USACE and SCDES-BCM. The team also provided grant application assistance for the SC Office of Resilience grant (SCOR), Flood Mitigation Assistance grant (FMA), and the SC Rural Infrastructure Authority grant (RIA).

By performing the condition assessment, JBC determined multiple flooding issues would be improved/resolved through maintenance activities. This resulted in the County acquiring drainage easements along multiple outfalls and performing maintenance activities, such as removing debris, trees, or other obstructions, and clearing a maintenance shelf for future work. JBC and the County also coordinated with SCDOT for maintenance of their assets.

The condition assessment also yielded one area, Hamrick Drive outfall, which required a detailed design for its improvement. A tidally influenced outfall, the Hamrick Drive area routinely floods during normal rain events, even during low tides. JBC initially performed preliminary hydrology & hydraulic (H&H) design to determine potential options to improve the outfall and presented them to the County. JBC and the team are performing the design and permitting for the selected option.

RESPONSIBILITIES: JBC is performing program/project management, coordination of subconsultants, hydrology & hydraulic (H&H) design, civil/site design for a stormwater pond, roadway design to Broad River Drive for the outfall improvement, QA/QC, stakeholder/public education & outreach program with public meetings, project branding, grant assistance and other items as needed.

JBC performed the condition assessment and prepared the report which included ownership (County, SCDOT, or other) responsibilities. JBC coordinated with the County to determine where drainage easements existed and where easements were still required. In addition, JBC also prepared bid documents for the County so they could advertise and select a contractor to perform their maintenance activities.

For the Hamrick Drive project, JBC is developing the preliminary, right-of-way, and construction plans for the stormwater pond and improvements to the outfall ditch and its crossing under Broad River Drive. JBC will also perform the MS4 and SCDES permitting and coordinate with the subconsultant for the USACE and BCM critical area activities permitting.