SCH Number 2002011094

Project Info

Title

Matilija Dam Ecosystem Restoration Project Subsequent Environmental Impact Report

Description

In October 2000, VCPWA – WP, then the Ventura County Flood Control District, initiated the Matilija Dam Ecosystem Restoration Study as a joint effort between Watershed Protection and U.S. Army Corps of Engineers to develop a project resulting in the removal of Matilija Dam. The primary Project objectives included: aquatic and terrestrial habitat improvement, facilitating the return of a viable and abundant run of steelhead trout; and restoration of natural sediment transport processes along Matilija Creek and the Ventura River. The secondary objective was enhancement of recreational opportunities along these two waterways. The joint Environmental Impact Statement/Environmental Impact Report (EIS/EIR) certified in 2004 evaluated alternatives combining dam removal, sediment relocation, flood protection (levees), two bridge replacements, new recreation features, giant reed removal, and water supply improvements. Technical studies to refine project features continued between 2008 and 2016, resulting in a new dam removal method and reevaluation of other project components. In June 2017, VCPWA – WP received funding to implement the Matilija Dam Removal 65% Design Planning Project, comprising additional technical studies, construction design, and CEQA analyses. The VCPWA – WP has determined that preparation of a Subsequent EIR is warranted to provide a complete and objective analysis of the revised Matilija Dam removal approach. Dam removal would be accomplished by creating two 12-foot diameter orifices drilled near the dam base which would be opened in advance of a large storm event. Storm flows would then be expected to transport primarily fine-grained reservoir deposits from behind the dam downstream to Matilija Creek, the Ventura River and Pacific Ocean. After an adequate amount of sediment is flushed from behind the dam, physical dam removal would be conducted. Habitat restoration would be accomplished by managed natural recruitment and non-native plant control. Adaptive management would monitor and correct post dam removal river flow obstructions to fish passage.

16 documents in project