Heights Road in Darien and commercial properties to the north frequently flood due to an undersized stream culvert beneath the road. Run off from the adjacent Connecticut Department of Transportation train station parking lot also drains to Heights Road immediately to the north. This flood mitigation project uses principles of Low Impact Development and consists of a combination of flood storage pipes beneath Heights Road and storage and infiltration structures with the fill beneath the nearby train station parking lot. The project addresses the needs of municipalities and businesses to reduce the impact of climate change and increased precipitation. The two objectives of this project were:
- To maximize the stormwater volume that is stored or infiltrated in order to provide greater flood resiliency to the existing stormwater system.
- To develop a Design Guidance Checklist that will have application to other flooding sites in Connecticut and clearly define tasks needed to evaluate and design stormwater management in urban areas that may contain historical urban fill. This is a complex process that can be challenging given the sometimes conflicting technical and regulatory requirements. Connecticut’s policies and regulations regarding stormwater quality, Low Impact Development (LID) practices, stormwater management and work in urban soils are in separate documents and permit programs.
The Town of Darien developed an alternative approach for flood mitigation of the Heights Road area by managing stormwater closer to its using concepts of Low Impact Development (LID). Flood mitigation strategies consist of a combination of flood storage pipes beneath Heights Road and storage and infiltration structures with fill beneath the train station parking lot. These measures will help reduce the frequency of flooding in Heights Road and the train station area and will not convey the flooding problem downstream. Infiltration of stormwater will also improve stormwater quality and recharge of groundwater. This Municipal Resilience Grant award was for the amount of $91,091.
Project Team Members
- Edward Gentile – Director of Public Works/Town Engineer, Town of Darien
- Emmanouil Anagnostou – UConn, Civil & Environmental Engineering