Location: Lake Forest, CA
Application: Detention
Number of Basins: 1
Product Used: 15′-0” DoubleTrap
Number of Pieces: 654
Total Water Stored: 534,771 cf
Foundation: Stone
Consulting Engineer: Hunsaker & Associates
Installing Contractor: La Strada Contracting
General Contractor: Toll Brothers
The Meadows will be a new luxury master-planned community located near 241 Toll Road in Lake Forest, CA. The development spans 122 acres with more than 500 residences across 6 distinct neighborhoods. The project will also feature seven parks, more than 10 acres of dedicated open space with trails, and a residents-only recreation center.
As part of the development and drainage plans for the property, a large underground stormwater management system was needed to accommodate the unmitigated upstream run-on flows and prevent downstream hydromodification impacts. Hunsaker & Associates, Inc. specified a StormTrap system that met all the requirements for the site.
The Central Park in Village Three was selected as the best location for the 12.27 acre-feet underground detention system. “The Central Park was the only open space area that was big enough to accommodate the large footprint and not interfere with the adjacent recreation facilities,” affirmed Kris Weber, Principal at Hunsaker & Associates, Inc.
According to the engineer, the initial project challenge was to find a system that would fit in the available area and provide the storage needed. During construction, the challenges were mostly logistical. The entire site was being graded at the same time as the detention basin was being installed. This made it difficult to stage the installation around the grading operations. Temporary access to the location and staging areas for the install had to be carefully chosen. StormTrap’s project managers worked closely with the engineering team, the precaster, and the installing contractor to coordinate the delivery and installation of the pieces.
The stormwater management final design was a 15’-0’’ DoubleTrap system, built with 654 modular units, capable of storing 534,771 cf of water. The basin has a 17′ tall outlet control structure built with DoubleTrap units and additional SingleTrap pieces on top that allow for water to be slowly released to the municipal sewer. It is connected to two 84” inlet pipes and two 54’’ outlet pipes.
The system was installed by La Strada Contracting in two phases and 29 days. Currently, the project is well under construction with the grading completed and backbone utilities being installed.
