The South Lakes community in Fuquay-Varina straddles Black Creek, a FEMA-studied stream with an established floodplain. The developer sought to connect the multiple phases of the development and allow easy traffic access to US 55 by extending Jones Lake Road across Black Creek via an existing dam. Before the dam could support a road, however, the dam needed to be widened and a spillway structure needed to be installed.
To understand how changes to the dam would impact the surrounding area, WithersRavenel developed a hydrologic and hydraulic model of Black Creek its associated drainage areas. These tools enabled the firm to appropriately design the dam improvements to protect the safety of downstream residents and properties.
In addition, WithersRavenel incorporated a private road, a greenway trail with a bridge over the spillway, and utility crossings. Through extensive agency coordination, WithersRavenel was able to design an aesthetically pleasing connector that met all required design and safety standards.
WithersRavenel obtained a Conditional Letter of Map Revision (CLOMR) from FEMA approving the impacts of the proposed dam improvements and recognizing that, upon construction, the project would affect the characteristics of the Black Creek and result in the modification of the floodplain. Once construction was complete, WithersRavenel worked with FEMA to approve a Letter of Map Revision (LOMR), which documented the revised BFEs on the relevant Flood Insurance Rate Map (FIRM) and Flood Insurance Study (FIS) report.