American Public Works Association
2013 Public Works Project of the Year
Small Cities/Rural Communities
Improving stormwater discharge from a dense downtown
Project: Riverfront Basin Stormwater Retrofit
Managing agency: City of Fort Myers, Fla.
Primary consultant: Johnson Engineering Inc
Primary contractor: Wright Construction Group
Cost: $5.7 million
You’ve got 15 acres of heavily developed downtown sitting on assets buried before the city’s founding in the late 1880s. The central business district runs along the environmentally sensitive Caloosahatchee River, which the state’s deemed impaired.
You’ve been tasked to meet a total maximum daily load (TMDL) to help reduce the river’s nitrogen levels. Most (80%) of the 15-acre downtown area is impervious. Due to the high groundwater table, existing soils and intensity of rainfall, underground systems and dry detention aren’t options for managing stormwater runoff.
That leaves one option: wet detention. But how to shoehorn a retention basin into such a dense downtown?
In 2009, the City of Fort Myers, Fla., launched an extensive riverfront redevelopment plan that’s spawned several innovations. In its first project using a construction manager, for example, Public Works upgraded all utilities beneath 52 blocks and completely streetscaped the area.
Having saved almost $3 million in the process, the department suggested treating stormwater runoff using a visually appealing waterfront attraction. A weir structure at the river’s edge hidden below a walkway appears suspended over the water but actually divides a 1.4-acre detention basin from the river to allow water in the basin to be treated before discharge. This solution provides the city with credit for reduced nitrogen loading to the river as well as excess treatment capacity for environmentally acceptable future development.
Even better, the city wouldn’t have to go into debt. Public Works loaned the Fort Myers Community Redevelopment Agency most of the $5.7 million project cost, to be repaid with tax increment revenues. The rest came from a state appropriation and state TMDL grant.
Since opening in December 2012, the basin is a focal point for public events. Pathways connect to the waterfront, along with passive recreation and healthy living benefits.
Next page: Returning a park shelter to its Depression-era roots