Baldwin & Sons increased the amount of buildable space at its Portola Hills housing complex in Lake Forest, Calif., by incorporating an expansive segmental retaining wall to create flat pads in place of valleys and hillsides. Coordinators of the project, which used Geogrid Retaining Wall Systems to construct walls around the complex’s perimeter, created solutions to manage soil quality challenges and weather issues.



In 2014, California-based developers Baldwin & Sons began the design and development of a housing complex on 99 acres of land in the city of Lake Forest, at the base of the Santa Ana Mountains—it’s currently about 2/3 complete.

The 931-unit development, The Oaks at Portola Hills, is comprised of seven neighborhoods of both single-family and multi-family residences. It boasts many amenities, including a location in one of the fastest-growing yet safest cities in the state, with nearby restaurants and shops and easy access to interstates. It also sits at the edge of the Limestone Whiting Ranch Wilderness Park, one of Orange County’s largest wilderness preserves.

uction-ready flat pads. A variety of Belgard Diamond Pro blocks engineered by Anchor Wall Systems as well as Belgard’s Vertica Virtual Joint (VJ) and Planter blocks were chosen to make up the expansive segmental retaining wall system that created the buildable space.

Constructing the Retaining Wall

To design and build the retaining wall, Baldwin & Sons chose to work with Geogrid Retaining Wall Systems, Inc., the largest segmental retaining wall installer in Southern California. Geogrid’s owner, Mike Stevenson, has more than 28 years of experience, including pioneering some retaining wall technologies.