Integral Consulting Team to Evaluate Ecosystem Impacts for Matilija Dam Project

Originally built in 1947 to store water for agriculture, the Matilija Dam in California has been obsolete for more than 20 years—trapping more than 6 million cubic yards of sediment and blocking access to endangered fish spawning habitat. Removal of the Matilija Dam has the potential to provide much-needed sediment to the Ventura River Lagoon and the coastal ocean, restoring critical habitat. As part of a contract with Ventura County, Integral and its partners, including Revell Coastal, AECOM, HT Harvey & Associates, and California State University Channel Islands, will conduct modeling of the lagoon and coastal ocean to help stakeholders understand the effects of sediment release associated with dam removal on the lagoon and coastal ocean habitat.

“Sediment released during the removal project will have short- and long-term effects on the local ecosystem that are important to understand and manage,” explains Integral Principal Craig Jones, Ph.D. “By applying validated hydrodynamic and sediment transport models, we can evaluate the estuarine and coastal habitat effects over multiple timescales.”

Sediment delivery to the lagoon and nearshore ocean depends on numerous interconnected physical processes, processes that will be incorporated into a coupled sediment transport model.

To evaluate the influences of the restored sediment loading to the lagoon and nearshore habitats, Integral will use a sediment transport model. Modeling of the lagoon and coastal ocean will provide high fidelity tools to characterize both the initial sediment pulse released from dam removal and the subsequent restored river sediment loads. These modeling tools will help to predict changes in water quality and to evaluate shoreline and nearshore habitat evolution under the joint effects of the Ventura River watershed, wave and tidal ocean processes, and sea level rise.

The dam removal project and associated modeling are part of a comprehensive long-term effort to support ecosystem restoration of the Ventura River watershed for multiple benefits. These include the protection and restoration of fish habitat and coastal wetland ecosystems, while enhancing more than 100 river miles throughout the watershed and along the coast of the Ventura River estuary. The project will open migratory access for the California steelhead trout and sustain high quality habitat for many other species.

The Matilija Dam restoration project is funded by the Ventura County Watershed Protection District through a grant from the National Fish and Wildlife Foundation. Dr. Jones is the principal investigator on the project and Kara Scheu, Ph.D., will serve as the project manager and lead modeler. Kaustubha Raghukumar, Ph.D., and Sam McWilliams of Integral will be involved in model development for the project.

For more information, contact Dr. Jones (cjones@integral-corp.com) or Dr. Scheu (kscheu@integral-corp.com).