Design and Construction of a 9-Billion Gallon Lined Upground Reservoir over Karst Geology: Delaware County, Ohio

The City of Columbus retained the team of ms consultants, inc., S&ME, Inc. and Moody Nolan to design an upground reservoir on one of three sites the City previously purchased in northern Delaware County, Ohio. When the need for a liner system was determined, the Design Team retained Dr. Patrick Fox, a UCSD professor, and Mr. Ronald Frobel of R. K. Frobel and Associates to assist with the selection and the design of a liner system.
The project also included the siting, permitting and design of a pump station with a capacity of 160 million gallons per day (mgd), a 150-foot-long inflatable weir across the Scioto River, and 20,000 feet of 72-inch-diameter pipeline connecting the water intake at the river, the pump station and the new upground reservoir.
The City had previously purchased about 2,500 acres for the construction of three upground reservoirs, an inflatable weir across the Scioto River and pipelines connecting the river, pump station and reservoirs.
Reservoir Site No. 2 contains 1,200 acres and consisted predominately of tree-lined agricultural fields, with one small wooded tract. The ground surface elevations ranged from about El. 906 to 934 feet above mean sea level. Ottawa Creek and one unnamed tributary generally flowed west to east across the northern portion of the site. Fulton Creek is located just west of the southwest corner of the site. There were a few residential and agricultural buildings on the site.
This paper focuses on the geotechnical and geologic challenges of constructing a new upground reservoir at Site No. 2 over an area with saturated granular deposits, karst geology and high groundwater levels in the granular deposits and in the limestone bedrock.