Case Studies Engineering Design for stormwater management

Lloyd Estates Drainage Improvements

Drainage Improvements to mitigate neighborhood flooding

The SAFEbuilt team was contracted to complete the design, permitting, bidding, and CEI services for the Lloyd Estates Stormwater Improvements project for the City of Oakland Park. The construction scope of work included 6748 LF of drainage pipes (15” to 36” diameter), 7702 LF of exfiltration trench, 204 storm inlets/manholes, regrading of swales, a drainage Pump Station and flood gate across Sleepy River, and associated roadway and utility improvements within the drainage basin area.

Prior to project construction, a Drainage Study and Hydrologic and Hydraulic modeling study was performed for the 285-acre Lloyd Estates drainage basin. The Lloyd Estates neighborhood had a history of flooding problems due to undersized and/or damaged underground storm drainage collection systems and poorly graded and silted roadside swales. The existing area experienced frequent flood conditions even at low intensity rain events due to limited discharge capacity and high tail water conditions downstream of the Sleepy River. In order to increase the flood protection Level of Service (LOS) for the area, additional swales/exfiltration trench and piping, and emergency flood gates and a pump station on the Sleepy River were recommended by the comprehensive study we performed.

The drainage system improvements will mitigate a considerable amount of damage caused by storm events by providing additional water quality treatment volume and storage volume, thereby reducing the durations of roadway flooding. The emergency flood gates and pump station will allow the City to aid in preventing the backflow of water from the C-13 canal into Lloyd Estates and to facilitate the lowering of the Sleepy River flood stages upstream of the structure so that the drainage improvements will function optimally. The project received grants from FEMA under the Hazard Mitigation Grant Program a result of Hurricane Wilma. SAFEbuilt also had assisted the City with the FEMA grant application process and requirements.

The scope of work, included civil engineering design, surveying, project management, electrical engineering design, structural engineering, landscape architectural and environmental services. In order to mitigate the neighborhoods flooding issues, the design incorporated extensive drainage improvements, water main relocation, milling and resurfacing of the roadway, and the construction of a drainage pump station with a bio-swale designed by our Landscape Architectural and Environmental Department.

One of the most challenging components of the project was the location of the pump station; in a residential neighborhood and drainage conveyance system improvements that took place near an elementary school. Due to limited space available at the location of the proposed pump station, the City acquired property adjacent to the Sleepy River for the pump station that provided an opportunity for the bioswale and other property enhancements.

While completed in 2017, this project demonstrates the strength and value of a long-term partner between the City of Oakland Park and the ongoing benefits to the community as SAFEbuilt continues to provide support with compliance monitoring and submittals.