The U.S. Army Corps of Engineers completed a federal Feasibility Study for the Matilija Dam Ecosystem Restoration Project in 2004, along with a joint EIS/EIR co-sponsored by Watershed Protection. Congressional authorization followed in 2007, however costs to implement the federal Project plan quickly escalated above the authorized cost ceiling due to complications from and community concerns with the proposed approach to sediment management and disposal.

To address these challenges, stakeholders convened a Design Oversight Group to oversee development of an alternatives analysis for the Project. This analysis considered additional engineering and design approaches successfully utilized in other recent large scale dam removal projects, which helped to demonstrate that natural sediment transport was a feasible and cost-effective solution for the Project.

With strong support from a diverse group of stakeholders, the Design Oversight Group met in 2016 and selected – with near unanimous agreement – a new approach to sediment release and management through “Uncontrolled Orifices With Optional Gates.” Shortly thereafter, the Matilija Project Funding Committee was established, and since 2017 has been working to assist Watershed Protection in developing critical funding pathways for all components and phases of the Project. (The Chronology summary below highlights key events related to Matilija Dam over the past 80 years, from 1940 to present.)

Design, planning and updated environmental studies for Dam removal and most essential downstream components are well underway thanks to a series of planning, design and implementation grants provided by the State of California from 2017-2022. (Construction of a new bridge – the first essential Project implementation component since 2008 – was funded in 2019 and completed in 2022.) Strategic support from the Resources Legacy Fund, Patagonia, Inc., and other non-governmental partners has also been key to the success of these efforts.


1940    Viable steelhead/salmon population (over 5,000) and other wildlife/natural resources

1945    County Bond issued passed for Matilija Dam construction at $682,000 projected cost

1947    June 18 – Construction begins

1948    March 14 – Matilija Dam completed – Report estimated 39 years (to 1997) before siltation would eliminate capacity – County sued engineers for cost overruns (but lost)

1949    Major fish kill behind Matilija Dam due to stagnant/hot water

1952    Reservoir filled

1959    Casitas Municipal Water District assumes responsibility for Matilija Dam under 50-year contract with Ventura County

1964    Bechtel Corp. Safety study condemns dam and presents removal as an option

1965    Bechtel Corp. estimates dam removal cost at $300,000 – County elects to notch dam (remove a section 30 feet deep and 285 feet wide) to reduce reservoir capacity to 65% to relieve strain and allow Dam to remain in place

1973    Study on littoral processes (Bickel) highlights impact to beaches – USFS estimates sediment contribution of Matilija’s dammed watershed to be 116,000 cubic yards per year

1978    Dam notched second time (358 feet wide)

1998    County resolves to remove Dam – Bureau of Reclamation begins Appraisal Study

2000    USBR Dam Removal Appraisal Study completed – Secretary of the Interior Bruce Babbitt visits for Dam removal demonstration project – Matilija Coalition formed

2001    Initiated the Matilija Dam Ecosystem Restoration Study between the Ventura County Public Works Agency – Watershed Protection and the U.S. Army Corps of Engineers

2004    USACE Feasibility Study completed – Ventura County Board of Supervisors approves the Final EIR/EIS – USACE Chief’s Report sent to Assistant Secretary of the Army

2005    Initiated the Design Phase of the Matilija Dam Ecosystem Restoration Project between the VCPWA-WP and USACE

2007    WRDA 2007 – Congressional Authorization – Fine Sediment controversy emerges

2009    Renewal of Matilija Dam operations agreement between Casitas MWD and VCPWA-WP, and transfer of the Matilija Conduit to Casitas MWD

2010    Fine Sediment Study Group convened

2011    Fine Sediment Study completed – Technical Advisory Committee formed

2012    Technical Advisory Committee Scope of Work finalized

2013    Consultant Team selected – Final Statement of Work negotiated

2014    Board of Supervisors approves contract

2015    Draft Report presented to Design Oversight Group

2016    Design Oversight Group reaches consensus on new approach to sediment management in conjunction with Dam Removal – Matilija Funding Committee established – Resources Legacy Fund announces Open Rivers Fund commitment to Matilija Dam removal

2017    California Department of Fish and Wildlife (CDFW)  awards $3.3 million to support MDERP 65% Design Planning Studies – National Fish and Wildlife Foundation awards $287,000 for Estuarine and Coastal Sediment Studies – Thomas Fire starts (December)

2018    Thomas Fire ends (January) – Proposition 68 (June) approved, Proposition 3 (November) defeated – RLF awards $100,000 to acquire Santa Ana Boulevard Bridge easements and for property appraisals for Camino Cielo rights of way

2019    CEQA Addendum completed for the Santa Ana Boulevard Bridge Replacement Project – CDFW awards $13.4 million to implement the Santa Ana Boulevard Bridge Replacement Project

2020    Wildlife Conservation Board (WCB) awards $5.025 million to complete final design plans for three levee projects and Matilija Dam removal – VCPWA publishes Notice of Preparation for a Subsequent EIR focused on Matilija Dam removal

2021    State Coastal Conservancy (SCC) awards $735,000 (increased to $810,000 in 2022) to advance design planning and updated environmental documentation for the Camino Cielo Bridge Replacement Project – SCC awards $380,000 for Phase 2 alternatives development at the Robles Diversion Facility

2022   WCB awards $1.3 million to bolster SCC’s investment in design planning and environmental studies for the Camino Cielo Bridge Replacement Project – CDFW awards $1.55 million to bolster SCC’s investment in Robles Diversion Facility Phase 2 design improvements – VCPWA completes construction of the Santa Ana Boulevard Bridge Replacement Project