At the bottom of every watershed is an outlet, either into another watershed, or into a large body of water. The Malibu Creek Watershed flows into Malibu Lagoon.

Lagoons act as large natural filters of water, cleaning out pollutants and debris before surface water makes it final journey out to sea. The maze of channels, the wetland plants, the tidal action, and the aquatic life contribute to the filtering and cleansing of water.

The Santa Monica Bay Watershed, which contains Malibu Lagoon is recognized as one of four estuaries in California currently listed in the U.S. EPA's National Estuary Program for the purpose of improving or maintaining coastal water quality (USDA NRCS MCWNRP 1995, p. 7).

Adjacent to the lagoon is Malibu Surfrider Beach, one of the most heavily used beaches in southern California. It is world-renowned for its excellent surf break and is used year-round.