Purpose

Human development has often taken for granted the support elements that comprise our environment- sunlight, air, water, soils, vegetation. These basic components provide the building blocks of our food web; the food web is a complex interaction of organisms and natural process that, when healthy, produces bio-diversity that can guard against catastrophic breakdown.

The purpose of this report is to provide the City of Calabasas, and others interested in issues of Las Virgenes Creek, a document with which to manage the watershed in regard to bio-diversity and human use, and to provide a model from which to draw on in similar geographic areas.

Development pressures, and the environmental sensitivities of the citizenry, has led the City of Calabasas to seek a watershed management plan that will protect Las Virgenes Creek, as well as provide a tool on which to base grant requests for related projects, and to expand the existing educational base.

Description of Study Area

Las Virgenes Creek runs south through the Santa Monica Mountains, joining Malibu Creek which ultimately empties into the Pacific Ocean; as such, Las Virgenes watershed is a sub-shed of Malibu watershed and the issues of the two watersheds are intertwined. Las Virgenes watershed is approximately 24 square miles, and Malibu watershed is approximately 105 square miles (Las Virgenes inclusive). Elevation within the watershed ranges from 500 to 2800 feet and annual rainfall averages 13.6 inches.

Las Virgenes watershed lies within two counties-- Ventura in the north, and Los Angeles in the south, approximately 1/3-2/3 respectively. In addition, The City of Calabasas lies in two watersheds-- Las Virgenes Creek (Malibu watershed) to the west, Los Angeles River to the east, approximately 1/3-2/3 respectively.

The watershed is located within an area of prime concern for environmental planning functions such as the Santa Monica Mountains National Recreation Area (National Park Service, United States Department of Interior), and Malibu State Park (California State Parks and Recreation Department). Two corridors for habitat movement have been identified within the watershed, and for this reason the watershed provides a key function for habitat linkage to the surrounding natural areas of the Malibu Mountains, Simi Hills, Santa Susana Mountains, and beyond.

The City of Calabasas was incorporated in 1991; before that it was an unincorporated town in Los Angeles County. As the first westerly post office outside the city of Los Angeles, just to the west of Woodland Hills (formerly Girard) in the San Fernando Valley, Calabasas cultivated an image of an outpost, or frontier town. To this day, this "Wild West" image is central to planning issues regarding character of the city.

This "frontier" location of Calabasas also was an underlying reason that the city did not receive water supplied by the Metropolitan Water District (state and federal supply) until the early 1970s. Before that, locals relied on local wells for water, however, the groundwater in the Calabasas area is notoriously poor in quality and quantity, and many people imported water from supply companies using tanker trucks. This expensive solution eventually led to pressure for an alternative; the result was connection with the MWD in the early 1970s under the management of the Las Virgenes Municipal Water District.

The incorporation of the city in 1991 was a response by local citizens to the development practices of the County, and legacy projects are still evident today as the industrial park corridor along US 101 continues to expand based on previously approved plans. The county refers to this as the Ventura Economic Corridor.

Prior to the establishment of Los Angeles County, Calabasas was part of the Spanish land grant system started in the 1700s. Before that, it was inhabited by native american tribes, predominantly Chumash.