Town of Bloomsburg – Columbia County – Flood Risk Management

Bloomsburg, PA

In 2011, Tropical Storm Lee brought record flooding to communities along the north branch of the Susquehanna River.  Hit particularly hard by the flood was the Town of Bloomsburg, prompting the Columbia County Commissioners to pursue a $30 million flood control system to protect two of the Town’s largest facilities and employers – Autoneum North America, and the former Windsor Foods plant.  Borton-Lawson developed an alternative “U-Shaped” design to the independent and isolated flood control systems around each property shown in the request for engineering proposals.  This approach allowed for cost savings, easier access behind the floodwall for personnel to monitor and operate systems during a flood, and can accommodate potential future expansions of the system.

Challenges V. Solutions

ChallengeGrant conditions required an aggressive design schedule for project delivery.

SolutionInvolved all key stakeholders in the project to promote a community understanding of the project, expedite regulatory approvals, and minimize unnecessary project delays by disseminating information and promptly addressing concerns or issues. This approach allowed for the project to be designed, authorized, and bid in a 12-month period.

ChallengeComplex environmental features such as wetlands and the proximity to landfills / hazardous materials required a thorough understanding of the site constraints in relation to the floodwall alignment.

SolutionPerformed environmental due diligence, tested multiple locations for evidence of hazardous materials, and hosted frequent meetings with regulatory agencies ensured the proper environmental mitigation measures were applied to the project and allowed a fast track U.S. Army Corps of Engineers Joint Permit process.

ChallengeTraditional subsurface seepage cutoff sheet piling systems under a portion of the floodwall compromised the stability of the wall due to soil bedrock conditions.

SolutionDesigned a slurry grout mixture for the subsurface seepage cutoff under a portion of the floodwall to better accommodate the geological constraints.

ChallengeMultiple appurtenant systems for interior stormwater and sanitary sewers were required to manage flooding interior to the floodwall.

SolutionDetailed hydrologic and hydraulic analyses were conducted to design a 30,000 gpm stormwater pump station to mitigate flooding and ponding on the interior of the floodwall. Several significant sanitary sewer lines also required a thorough evaluation of comprehensive sanitary flow data and detailed engineering analyses to design sanitary pump stations and control structures.