Sep 13, 2017

Large Underground Detention System Coming to Southern California

Large Underground Detention System Coming to Southern California
Large Underground Detention System Coming to Southern California

Oldcastle Precast is collaborating with site owner LS-Oc Portola LLC, general contractor Landsea Holding Corp., and engineering firm Hunsaker & Associates to create one of the largest and deepest StormCapture rainwater detention systems designed to date.

The structure includes a network of individual modules arranged to create a vast underground precast concrete storm water management system. The pre-engineered components allow for site-specific configurations while providing large storm water storage capacity in a smaller footprint.

Portola Center is a 195-acre community development, divided by Glenn Ranch Road into Portola North and Portola South in Lake Forest, Calif. The 95.5-acre Portola Center South community features new single-family homes and mixed-use buildings. The community also features a 10,000-sq-ft ground floor commercial space as well as a 5-acre public park and perimeter trails.

The magnitude of this project and its increased impermeable areas made managing hydromodication (storm water runoff) a top priority. Storm water is managed throughout the project through 10 basins, providing a total detention storage volume of 820,886 cu ft (18.85 acre-ft). Basin No. 5, the first StormCapture detention system installed at Portola Center South, was designed to store 198,152 cu ft (4.55 acre-ft) of storm water, which can detain up to a 10-year storm event with an internal orifice designed to slowly discharge the water volume to a downstream biofiltration system.

The Basin No. 5 StormCapture system, manufactured at the Oldcastle Precast plant in Perris, Calif., has an inside height of 14 ft and was designed to withstand 16 ft of backfill over the entire system. The system was fully encased with an impermeable geotextile liner. Along with the StormCapture detention system, Oldcastle Precast plants in Southern California also manufactured and delivered large biofiltration units to address the water quality requirements for the project.

“Oldcastle Precast is the perfect design partner for all storm water needs, big and small,” said Shelby Hull, director of Oldcastle Stormwater for the Southwest region. “Our team of storm water experts, design engineers and national manufacturing capabilities make Oldcastle Precast the clear choice for developing custom solutions to meet the specific regulatory needs for projects like this. Unlike other companies that only design systems and then use third-party manufacturing, Oldcastle Precast maintains control and ensures quality throughout the design, manufacturing, installation and life of the system.”

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