The Malibu Creek Watershed, at 109.9 square miles, is the second largest watershed draining into the Santa Monica Bay. Any water that falls within the boundaries of the Malibu Creek Watershed will eventually find its way to the Malibu Lagoon, via the system of surface streams and groundwater.

The watershed is located approximately 35 miles to the west of the City of Los Angeles in the Santa Monica Mountains and Simi Hills. Within its boundaries are the cities of Agoura Hills, Westlake Village, and portions of Malibu, Calabasas, Thousand Oaks, Hidden Hills, and Simi Valley.