Wastewater / Stormwater Collection
Bancroft Mills Sewer Public / Private Collection
The sewer collection system within the former Bancroft Mills site was initially installed and owned by the Bancroft Corporation. As the operation of the mills was gradually phased out, both the mills property and the sewer collection system changed hands to new owners. Managing this aging collection system is made more challenging by the complexity of handling multiple public and private sewer flows.
The City is currently exploring strategies to streamline and efficiently manage the sewer flows generated in this area. This initiative aims to prevent deferred maintenance and potential overflows into the Brandywine River.
Green Infrastructure Projects
The Public Works Department is always looking for innovative ways to reduce and manage the stormwater runoff that is generated within the City each time it rains. Rain gardens, bioswales, tree trenches, and other similar stormwater management features are collectively known as Green Infrastructure. Projects like this reduce the quantity of runoff that must be managed while also improving the quality of stormwater by capturing nutrients in these green features while also providing much need green space in an urban environment.
Combined Sewer Overflows System Management
The City's 120-year-old sewer collection system is a network of 300 miles of buried pipe. Approximately 90% of these pipes handle both sanitary sewer flow and stormwater runoff, directing it to the City-owned wastewater treatment plant. However, during high-intensity storm events, the volume of runoff from rainfall exceeds the capacity of the collection system. Consequently, a portion of the combined stormwater and sanitary sewer flow overflows into the Brandywine and Christina Rivers. These occurrences are termed combined sewer overflows (CSOs). More information can be found on the Wilmington CSO website.
Managing the Combined Sewer Overflow (CSO) collection system is a crucial responsibility of the Department of Public Works. The City has devised a comprehensive Long Term Control Plan, which has been submitted to both State (DNREC) and Federal (EPA) regulators. The primary aim of this plan is to safeguard the Christina, Brandywine, and Shellpot waterways by reducing the frequency and volume of overflows that happen during rainfall.
Key components of the program include monitoring and controlling flow and storage in the system through Real-Time Control, implementing in-system and offline storage such as the Canby Park Tank, enhancing pumping at the 11th Street Pump Station, and initiatives to diminish runoff by installing Green Infrastructure like the Southbridge Wilmington Wetlands Park, Cools Springs Park, Spencer Plaza, and the Urban Arts Amphitheater. Read more about Clean Waterways.
Resiliency & Flooding
Climate change and sea level rise have underscored the urgent need for implementing resilience and flood mitigation measures. For decades, the Southbridge Community has grappled with recurring flooding challenges. Meanwhile, communities like Northeast Wilmington and the 11th Street Bridge area are still recovering from the devastating impacts of flooding caused by events like Hurricane Ida. Initiatives such as the Southbridge Wilmington Wetlands Park represent the initial steps toward enhancing Wilmington's resilience.
Currently, the City is conducting flood resiliency studies in South Wilmington, Northeast Wilmington, and the 7th Street Peninsula. These studies aim to assess risks and develop proposed alternatives to bolster the resilience of each community. Read more about the Resilient Wilmington program.