CATEGORY: Water Resources

OWNER: Sny Island Levee Drainage District

PROJECT FIRM: Klingner & Associates

DESCRIPTION: Several design and construction innovations made the SILDD pump stations possible. First and foremost, Klingner utilized its signature siphonic pump station design – but at its largest scale yet. Nationwide, pump stations are commonly designed to draw water by continuously pumping against the full height of a levee, requiring a high sustained fuel usage. Klingner’s design forms a siphon to reduce static head conditions, enabling the pumps to operate with reduced engine horsepower and fuel usage. Stations No. 1 and 3A push the limits of this technology due to their size. Station No. 1 increased the location’s overall pumping capacity 164% to 370,000 GPM, while Station 3A’s location has seen a 126% increase for a total pumping capacity of 610,000 G PM (100-year flood). Each pump needs to prime against the 30+’ levee height while remaining functional against head conditions as low as 6’ TDH when siphon recovery is in place and as high as 31.8’ (Flood of Record). Therefore, diesel engines must operate in a range of 500 - 1,600 HP. Only two manufacturers were capable of supplying engines meeting these unique requirements and fulfilling EPA Tier 4 emission standards. Large diesel engines powering immense pumps generate excessive heat, posing risks to equipment and operators. Klingner coordinated the design of a sophisticated, external coolant piping and radiator setup with Central Power Systems and MTU. Waste heat is discharged outside, avoiding previous heat exchanger fouling issues. Generators to power the electric radiator fans accompany the engines for continuous pumping. Also noteworthy is the use of a permanent sheet pile sump structure. The sump depth designed to meet the Hydraulic Institute Standards and physical modeling was such that traditional cast-in-place concrete design and construction would be costly and difficult. Alternatively, sheet piling was driven and a concrete seal was placed underwater within the sheet pile sump box. Once sufficiently cured, the sump was completely dewatered. Cast-in-place concrete finish slab and walls were then placed to provide smooth flow paths into the sump and pumps. This technique lessened dewatering costs and created the required deep foundations.