The Ballona Wetlands are located in Southern California, USA south of Marina del Rey and east of Playa del Rey. The wetlands once included the areas now taken up by Marina del Rey, Venice, and Playa Vista, extending north to about present-day Washington Blvd. in Venice. It is one of the last significant wetlands areas in the Los Angeles basin, and is named for Port Ballona and Ballona Creek which now runs through the area as a flood control channel. In the 1930s the Ballona Creek corridor was channelized in concrete, thus greatly reducing the inflow of salt water to the marsh, and eliminating spring floods which brought freshwater to the wetlands. Among groups dedicated to protecting the wetlands is the Friends of Ballona Wetlands.