Brandon Flaherty, Louisville MSD
Nick Ulliman, Ulliman Schutte Construction
Ulliman Schutte and HDR are cooperatively designing and constructing the new Paddy’s Run Flood Pump Station for the Louisville and Jefferson County Metropolitan Sewer District (Louisville MSD) in Kentucky using progressive design build project delivery. The project is currently under construction and will be completed in 2026. Progressive design build delivery is being utilized to foster collaboration between the Owner, Engineer, and Contractor; expedite an aggressive schedule; and promote innovation. To meet the design storm event of 5 inches of rainfall in 24 hours, Louisville MSD is replacing the existing station with an upgraded facility to be able to pump a maximum flow of 1,900 MGD (2,940 CFS) to protect the community when the Ohio River reaches flood stage. This pumping rate would be capable of filling an Olympic-sized swimming pool in just 30 seconds. The pump station layout was designed with a unique opposite/offset configuration to reduce overall footprint and minimize impact to the levee system. The new pump station will house eight (8) low-head, high flow capacity, mixed flow type pumps including six (6) pumps with a design capacity of 200,000-gpm with 2,900-HP motors and two (2) pumps at 80,000-gpm with 1,500-HP motors. Each pump will be equipped with a formed suction intake to provide effective flow regimes into the pump columns and prevent detrimental vortexing and cavitation. Pump motors will be synchronous type with DC exciters for energy efficiency. The welded steel discharge pipes will be routed over the levee to a concrete basin to provide siphon head recovery which is used to minimize the size of the pumping equipment and reduce overall operating/energy costs. The concrete basin will be filled at the pumps’ discharge to submerge the pipe outlets to maintain the siphonic system. Control valves will be used at the top of the levee to initiate the siphon upon pump startup and break the siphon upon shutdown to prevent the risk of back flow. Overall slope stability improvements are being made to the levee. Also, construction of a deep diaphragm wall system will provide seepage “cut-off” and furnish the building with its permanent foundation system to meet current USACE standards. Further, all required electrical, mechanical, and instrumentation will allow the automated operation of the new flood pumps including integration into MSD's existing SCADA system. There were several tools used during design including physical modeling, computational fluid dynamics (CFD) analysis, and virtual reality. Physical models were constructed in a laboratory at a 12:1 scale to verify the design concept for both the intake/wet well and the discharge pipe/siphon head recovery system. A CFD model analysis was used in the design of the pump station’s discharge basin to quantify the maximum hydrodynamic forces and optimize the design of the structural pile foundation system. Finally, the Team visited the University of Dayton’s Virtual Reality Lab to “walk-through” an immersive 3-D Model of the facility to review operation and maintenance and enhance the overall layout of equipment.