TreePeople is a nonprofit organization that addresses urban issues, such as water and energy conservation, Hood prevention, and storm- water pollution. The TreePe0ple Center for Community Forestry is a state-of-the-art environmental education campus in California’s Cold- water Canyon Park.
Owner: TreePeopIe, Los Angeles
Concrete Producer: Catalina Pacific, Los Angeles
General/Concrete Contractor: PCL Construction Group, Edmonton, Alberta, Canada
Material Supplier: Kryton International, Vancouver, British Columbia, Canada
Designed to achieve a LEED Platinum rating, the center features a 250,000-gallon underground concrete cistern. The largest of its kind in the continental U.S., this tank captures rainwater to irrigate the center’s gardens and forests. The cistern is covered with landscaping, including an elaborate labyrinth. Because access for maintenance and repairs is al- most impossible, the owners needed a permanent waterproofing solution for the structure. Because conventional waterproofing membranes deteriorate over time, the center’s owners opted instead to add a cementitious admixture to fresh concrete and the manufacturers waterproofing system. When it is added to the concrete mix, this admixture cures to form crystals that fill the spaces between concrete particles, permanently waterproofing the structure. It also reacts with incoming water to self-seal any small concrete cracks, providing
lasting protection against leakage from any direction.