Portola Center is a 195-acre community development in Lake Forest, Calif., divided by Glenn Ranch Road into Portola North and Portola South. The 95.5-acre Portola Center South community features new single-family homes and mixed-use buildings with senior affordable units, and townhomes. The community also features a 10,000-square-foot ground floor commercial space, as well as a five-acre public community park and perimeter trails.
The magnitude of this project and its increased impermeable areas made managing hydromodification (stormwater runoff) a top priority. Stormwater is managed throughout the project with 10 separate basins, providing a total detention storage volume of 820,886 cubic feet (18.85 acre-feet).
Oldcastle Precast worked with owner LS-OC Portola LLCL, general contractor Landsea Holding Corporation, and engineer Hunsaker & Associates to design and manufacture several of the largest and deepest StormCapture stormwater detention systems installed to date. StormCapture is an underground precast concrete stormwater management system. Its pre-engineered components allow for site-specific configurations, while providing large storage capacity in a small footprint.
Basin No. 5, the first StormCapture detention system installed at Portola Center South, was designed to store 198,152 cubic feet (4.55 acre-feet) of stormwater, which detains up to a 10-year storm event with an internal orifice discharging the water quality 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 feet and was designed to withstand 16 feet of backfill over the entire system. The system was fully encased with a geotextile and impermeable liner.
Information provided by Oldcastle Precast (www.oldcastleprecast.com).