Calleguas Creek

Existing conditions:
The Calleguas Creek Watershed area is 30 miles long, 14 miles wide and has an area of approximately 343 square miles (approximately 224,000 acres).  It extends from the Los Angeles County line in the east to Mugu Lagoon and the Pacific Ocean to the south.  The watershed includes Calleguas Creek, Conejo Creek, Arroyo Los Posas, Arroyo Conejo, Arroyo Santa Rosa and Arroyo Simi, along with Revolon Slough and Mugu Lagoon.  The northern boundary of the watershed is formed by the Santa Susana Mountains, South Mountain and Oak Ridge; the southern boundary is formed by the Simi Hills and Santa Monica Mountains. Discharges of municipal, agricultural, and urban wastewaters have increased surface flow in the watershed, which has resulted in increased sedimentation and water pollution in the Mugu Lagoon.

Anadromous Fish:
No fish passage impediments noted in lower reach of the Calleguas Creek have been identified for steelhead.  The farthest upstream limit is due to 15 ft.  drop structures located at Simi Valley (Madera Rd.). There is low quality adult resting habitat and poor quality juvenile rearing habitat (sediment).

Description of Watershed Resources:
Area: 242578.07 acres
Naturally Occurring Waterways: 483.15 miles
Percentage of Free Flowing River Miles: 77 %
Percentage of River Miles in Protected Lands: 0 %
Protected Lands: 0 %
Number of Dams: 6
Number of Selected Watershed Projects: 6
Number of Stream Crossings: 832
Near-Stream Roads: 353.18 miles
Average Precipitation per Year: 15.06 inches
Percentage Area above 15% Slope: 7.77 %
Number of CalWater Units: 11
WBS TMDL Rivers 18
Number of Special Status Species: 22

Status of Watershed Planning Efforts:
The Calleguas Creek Draft Watershed Management Plan, with its broad stakeholder participation and support, has an opportunity to address long range comprehensive water resource issues; land use; economic development; open space preservation, enhancement and management issues; and public facility provision strategies. The Plan will examine existing data, and develop a characterization of the watershed.
The Plan will give balanced consideration to habitat conservation, hydrology, land use, regulatory processes, agriculture, flood control, soil conservation, water quality and quantity, water conservation, habitat preservation, species endangerment, recreation, private property rights, economics and overall community objectives.

Restoration Goals and Objectives Related to Wetlands:
The Navy has undertaken 3 wetland restoration projects since 1995, resulting in a total of 23.5 acres of tidal mudflat, sandflat, channels, ponds, salt marsh and sand islands; mitigation plans were being developed in early 1997 for restoration of a 37-acre site to predominantly salt marsh.  Several studies focused on reducing flooding and sedimentation have led to installation of sediment control structures, stream bank stabilization projects, on-farm sediment basins, and adoption of range management practices.  Local communities have also instituted grading and hillside erosion control ordinances.

List of Major Restoration Activities:
Additional watershed-related planning efforts underway, include Calleguas Creek Watershed Treatment, McGrath Lake Oil Spill Restoration Project, and Ventura County Punagrass Control. 
Calleguas Creek Watershed Treatment Phase I-II is a comprehensive effort to protect resources within the Calleaguas Creek watershed and at the outlet, Mugu Lagoon.  This project will demonstrate subwatershed channel stabilization through the use of grade stabilization and streambank restoration.  Phase I of the project addresses priority subwatersheds of the Calleguas Creek Watershed.  Selected conservation practices and technical assistance will improve water quality by reducing erosion, runoff and sediment transport to downstream water bodies.  Phase 2 will focus on subwatershed channel stabilization through the use of grade stabilization and streambank restoration.