TreePeople, a Los Angeles nonprofit organization that has planted more than 1.5 million trees over the last 26 years, is now aiming to create a “sustainable watershed” in the city, dramatically reducing flooding, drought, and pollution. TreePeople founder Andy Lipkis has built a demonstration house in South Central L.A. that has a lowered lawn and a drainage and filter system in the yard, intended to capture rainwater and use it to nurture greenery instead of letting it run into the gutters. Lipkis would like to see similar rain recycling systems at every L.A. residence. TreePeople recently helped engineer the greening of 400 schools, convincing officials to plant trees and grass around buildings instead of putting in 60 million square feet of new asphalt.