Hendry County has recently completed the first phase of a multi-phase improvement project for County Road 78 by constructing two new box culverts at Pollywog Creek and Kell Mill Boulevard in north LaBelle. Rather than simply resurfacing the existing roadway the County took the initiative to address some larger drainage issues that have plagued the north LaBelle neighborhood. A drainage study revealed the existing box culvert at Pollywog Creek was undersized and the aging metal arch pipe at Kell Mill Boulevard was soon to become a maintenance problem.
The Pollywog crossing was of particular concern with a large watershed extending well into Glades County. Drainage models predicted the creek would overtop the roadway in larger rainfall events, potentially severing the only east-west corridor for the neighborhood. The new structure was designed such that it could be constructed without shutting down the roadway or impeding the flow of the creek. In addition to providing much needed additional capacity, the new culvert also restored the natural flowline of the creek allowing the creek stages to return to their historic levels. A concrete sediment basin was also incorporated, cast monolithically with the footer of the upstream headwall to catch nutrient laden sediment before it enters the Caloosahatchee River. By providing a mechanism to remove both nitrogen and phosphorus the County received a grant from the South Florida Water Management District helping to fund the project.
The project was finished within budget and perhaps more importantly on time, just before the rainy season. Subsequent phases of the project will address the roadway drainage, resurfacing, and sidewalks. This project serves as a great example of designing for the future…smart, simple, and sustainable.
For more information contact Ryan Bell, P.E. at firstname.lastname@example.org.