STORMWATER MANAGEMENT/All along the waterfront

Employees for Palm Bay, Fla., created a unique solution to the city’s flooding problems by designing a stormwater management system that simultaneously provides recreational opportunities for residents. The results are protecting residents’ homes from damage during storms, protecting habitats for endangered birds and reptiles, and preserving open space for passive recreation activities.

Palm Bay, a city of 86,400 residents in central Florida, is located on the shores of the Indian River Lagoon and Turkey Creek. The lagoon is part of the National Estuary Program and home to myriad plant and animal species, and the creek is one of its tributaries. The beautiful environment attracted developers who built homes on the banks of the creek but made little or no provisions for removing pollutants from stormwater runoff into the creek. Years of polluted stormwater began to take their toll on the water quality of the creek and the lagoon, threatening the habitats of endangered animals.

Gradually, urban development consumed the land that was needed to perform stormwater treatment using traditional methods. Additionally, waterfront property developed so quickly that residents lost access to Turkey Creek. Moreover, development increased the amount of stormwater runoff, which eventually exceeded the capacity of the drainage system, resulting in flooding.

In the late 1990s, the city began searching for ways to resolve the flooding problems, improve water quality in the lagoon and creek, and restore access to the water for recreation activities. Mike McCabe, staff engineer for the city’s Engineering Division, designed a stormwater collection and distribution system that included a 2.23-acre retention pond where stormwater would settle before flowing into Turkey Creek. Additionally, McCabe designed trails, fishing piers and creek observation platforms on approximately 30 acres around the retention pond to provide recreational opportunities for residents.

During the final stages of the design, McCabe worked with the state Historical Office and a consultant to perform an archeological survey of the project area. The team discovered a pre-historical site that contained a 70-centimeter thick deposit of shells, ceramics and other artifacts that was added to the state registry. Rather than disturb the site, McCabe redesigned the project to ensure the sensitive site was protected.

City employees from the Transportation and Drainage Division and the Parks and Recreation Department constructed the stormwater system and recreation facilities. Work included digging a retention pond; installing underground pipes to convey water from the pond to the creek; building concrete and mulched bicycle and pedestrian paths, restroom facilities, scenic overlooks and gazebos; and preparing a canoe launch on the creek bank. A local volunteer organization, Trailpartners, helped map the trail system by using GPS technology, and it helped cut the trails during the project’s construction. The project was completed last spring.

The city monitored water quality in the creek and lagoon before and after the construction of the retention pond to quantify the amount of contaminants removed by the pond. The city found that the system removed 76 percent of total suspended solids, 54 percent of total phosphorous and 33 percent of total nitrogen. The system has relieved the flooding problem and is providing stormwater treatment for a 110-acre watershed of residential and commercial properties.

Palm Bay financed the project with $802,000 in grants from state and regional agencies. It also used $600,000 from the city treasury to complete the project.