Columbia County Flood Risk Management System

Project: Columbia County Flood Risk Management System
Location: Bloomsburg, Columbia County, PA
Owner/ Client: Columbia County

Project Administrator: SEDA-COG

Project Status: Phase 1 Complete, Phase 2 Ongoing

Challenges V. Solutions

Challenge In 2011, Tropical Storm Lee resulted in the Susquehanna River cresting at a historic flood stage. Large sections of the Town of Bloomsburg were inundated with flood waters, causing millions of dollars in damages and threatening the Town’s primary employer. Autoneum has been a strong foundation for the Town of Bloomsburg’s economy for over 100 years. The company employs nearly 700 people at its Bloomsburg facility to supply acoustic and thermal management systems to a vast array of automobile manufacturers. Another manufacturer employed over 150 people. Each company had seen an increase in the frequency of flooding from the Susquehanna River and knew it was time to take action.

Solution A preliminary concept developed by the stakeholders included individual levees around the businesses. Borton-Lawson developed an alternative “U-Shaped” design to allow for better access, cost effectiveness, and the ability to expand the levee system in the future.

Extensive hydrologic and hydraulic modeling of the Susquehanna River and Fishing Creek was performed utilizing HEC-RAS. With Tropical Storm Lee being the flood of record at the project location, much of the hydraulic analysis for the Susquehanna River focused on calibrating the HEC-RAS models to Tropical Storm Lee observed flood elevations based on the United States Geological Survey (USGS) stream gaging station at Bloomsburg (Susquehanna River). Upon calibrating the existing conditions HEC-RAS models, the proposed flood protection system was coded into the models’ geometry to evaluate the effect of the flood protection system on the hydraulics of the Fishing Creek and the Susquehanna River.

Multiple road closure structures and two railroad closure structure were designed to block the path of floodwater at openings along the levee. Numerous flow control structures were designed at all storm and sanitary sewer crossings of the levee. These flow control structures were necessary to prevent floodwater from entering the sewers and flowing back to behind the levee. In conjunction with the flow control structures, a 30,000 gallon per minute stormwater pump station and three sanitary sewer pump stations were designed to evacuate interior stormwater and wastewater flows.

This complex project was designed and permitted within 12 months and constructed with 18 months at a total cost of approximately $29 million. The system was operational in October 2016 and the second phase of the project is anticipated to be fully operational in 2020.