Citywide Watershed Master Plan | City of Fayetteville

Gradient’s collaboration with the City of Fayetteville featured comprehensive studies across multiple drainage basins, paralleling the extensive watershed planning necessary in Raleigh. This work showcases Gradient’s capability in managing large-scale projects effectively with a team comprised of multiple subconsultants.

Overview

The City of Fayetteville, with 15 drainage basins, had not undergone a complete drainage study until 2020,when Gradient was hired to assess four basins. Phase I developed H&H models and inundation maps for high-priority sub-basins, used HEC-RAS for primary stormwater systems, and Info Works ICM for secondary systems, with additional 2D and unsteady modeling as needed.

The Bones Creek Watershed project included a detailed H&H analysis over 2.0 square miles and 12 river miles, subdividing the watershed into 429 sub-basins for citywide analysis. Inundation maps showed flooding extents for various storm events, identifying concern areas and flooded structures. The primary hydraulic analysis developed a steady-state HEC-RAS model using peak discharges from the revised citywide.

HEC-HMS model, while an InfoWorks ICM model was created for the secondary system. These models predicted flooding for 2-, 10-, 25-, 50-, and 100-year, 24-hour rainfall events, identifying 88 concern areas, with 40 chosen for proposed solutions.

Gradient Solution

Gradient completed the Cape Fear and Bones Creek subwatersheds and is developing a Buckhead Creek watershed plan, leading technical model maintenance and design standards development. CIP projects identified during studies or from known flooding issues are being designed, with Gradient assisting the City on stormwater infrastructure improvements, developing ICM and PCSWMM models, and providing full design and construction administration.

Award Winning Program

2024 ASFPM James Lee Witt Local Award for Excellence. The City of Fayetteville won the 2024 ASFPM James Lee Witt Local Award for Excellence for the Watershed program! The award was announced at the Association of State Floodplain Managers 2024 National

Conference in Salt Lake City, Utah on June 27, 2024. The award seeks to find and recognize outstanding programs or activities at the front lines of floodplain management — local programs where “the rubber meets the road.”