The site design for a new 2-million-gallon finished water ground storage tank and booster pump station in a fully developed area of the City posed a stormwater runoff management challenge. The storage tank and booster pump station are located on a former bank site that featured no existing stormwater infrastructure and simply sheet flowed runoff to Hampton Blvd, a major thoroughfare in the City of Norfolk. Ultimately, a stormwater solution was developed through a partnership with the City of Norfolk and Virginia Port Authority (VPA) that benefited both parties and the public.

The initial stormwater design approach was to connect to the nearest curb inlet on Hampton Blvd. which was located 150 ft south of the tank site. After performing additional field evaluations, major challenges including an abundance of utility conflicts and stormwater ponding issues on Hampton Blvd. were identified. Preliminary solutions for addressing these utility conflicts consisted of installing conflict manholes, adjusting communication duct banks, and offsetting an existing 24-inch water main. All these approaches would be costly, disruptive to the public, and would contribute to the ponding issues on the road. This approach would also have required the City to drain the tank to the already overcapacity Hampton Blvd. drainage system on an infrequent basis.

A more cost-effective alternative solution was proposed to utilize the drainage infrastructure on VPA’s property adjacent to the tank site. The alternative solution required hydrologic and hydraulic modeling and water quality calculations to be performed and presented to VPA and DEQ for approval. This presentation will provide more details on the ultimate design solution and highlight the benefits in developing a partnership to solve a complex stormwater design challenge.