With infrastructure costs mounting, particularly those related to stormwater, the City of Suffolk needed to develop a stormwater utility fee structure to fairly assess residents and commercial developers. Looking for guidance, the city partnered with Clark Nexsen to develop an overall master plan. Leveraging the GIS team’s expertise ensured the city conforms to Virginia Pollutant Discharge Elimination System (VPDES) Phase II requirements.
Ultimately leading to the delivery of a GIS-based, interactive system for the city’s entire storm drainage system and a prioritization of capital improvement projects, our team completed an inventory and condition assessment for all major outfalls within a 300 square mile portion of the city; the delineation of all of the major watersheds within the city; the development of a database to support the pro rata policy; the development of the pro rata policy for developers; and an inventory and inspection of the downtown core area.
To develop the GIS-based, interactive system, the team began by gathering information from a variety of sources including, but not limited to, city personnel, imagery, existing GIS data, and hard copy records and drawings. With the establishment of horizontal and vertical controls, using network-based Real-Time Kinematic (RTK), an estimated 300 major stormwater outfalls and drainage pipe location and attribution were collected. Using XP-SWMM software, a model was constructed based on GIS coverages and current USGS quadrangle maps. The end product was a comprehensive report, which included a detailed cost analysis.