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Matilija Dam
THE DAM
Matilija Dam, located in the Ventura River watershed on Matilija Creek north of Ojai, is a concrete arch dam built in 1947. Infamous for the scissors painted on the dam by graffiti artists in 2011 that have become an iconic symbol for dam removal, it was originally designed for water storage and flood control.
Owner:
Ventura County Watershed Protection District
Matilija Dam Location:
Ventura River, north of Ojai
Completion Date:
1947
Size:
Height: 168 ft, Length: 620 ft, Total designed capacity: 7,018 acre ft., Current capacity: less than 500 acre ft.
Stakeholders:
Ventura County Watershed Protection District, California Department of Fish and Wildlife, Matilija Coalition, Patagonia, CalTrout, State Coastal Conservancy, Surfrider Foundation, National Marine Fisheries Service, Wildlife Conservation Board, Pew Charitable Trust, Resource Legacy Fund, Ojai Valley Land Trust.
Land Acknowledgment
Matilija Dam is located on the ancestral lands of the Chumash Tribe including the Barbareño Band of the Chumash Tribe and the Barbareño/ Ventureño Band of Mission Indians.The Problem
The reservoir behind Matilija Dam is nearly completely clogged with sediment, significantly reducing storage capacity to the point that the dam is rendered non-functional. With no fish ladder or bypass structure present, it is a complete barrier to the migration of endangered Southern California steelhead. The dam also causes degraded water quality, an altered flow system, and a disorder to the sediment flows towards the lower watershed, estuary, and beaches, which need sediment to replenish themselves. Matilija Dam has impounded approximately eight million cubic yards of sediment, and the physical condition of the 70+ year old dam continues to deteriorate. Historically inhabiting the Ventura River watershed, Southern California steelhead are an incredibly important species because they evolved in seasonally disconnected river systems and are an adaptable species, able to survive in warmer waters than other steelhead populations. With only an estimated 500 individuals remaining, this unique life history trait makes them a particularly valuable population to protect in the face of climate change and shifting weather patterns. Removal of Matilija Dam will reconnect access for steelhead to 17 miles of spawning, rearing, and foraging habitat above the dam. Reconnecting this habitat will help bolster species-wide recovery for Southern steelhead across Southern California.
Current Situation
Spanning 20 years of effort, a broad coalition of community groups and resource agencies have advocated for Matilija Dam removal, working together to develop a comprehensive strategy to restore the Ventura River. The specific project we are currently implementing, the Matilija Dam Ecosystem Restoration Project, will cost millions of dollars. Unfortunately, we’ve experienced a lack of dedicated funding, which has been a major impediment to action. Other factors, such as determining an appropriate release strategy for all the sediment build-up, modifying downstream roads, levees, and bridges, and impacts from the Thomas fire on the surrounding landscape, have all added to the challenges of the dam removal undertaking. Ventura County is preparing the 65% plan for removal of Rindge Dam with anticipated completion of this work by the end of 2024. Extensive assessment and modeling of the sediment, hydraulic and hydrologic processes is necessary to support the removal of the dam. Just recently this project received an additional $1.73 million dollars from CDFW to support this work. This phase will be immediately kick-off the final design and planning effort. Ventura County has secured $8.5M from the Wildlife Conservation Board (WCB) for this work. These funds also include the necessary funding to secure plans to update all downstream flood protection projects. In 2022, the first major component of this project was fully constructed. With funding from California Department of Fish and Wildlife (CDFW), Santa Ana Bridge was replaced. The bridge is downstream of the dam and built to reflect an altered river system. The new expanded span size begins to set Ventura River free. During a recent flood event, the new bridge improved the ability of the Ventura River to transport sediment and handle flood waters. The new bridge also expanded fish migration opportunities for Southern steelhead at former passage bottle neck location. Ventura County received $2.11 million from State Coastal Conservancy and the Wildlife Conservation Board to fully fund Camino Cielo Bridge final designs and planning. This part of the project will replace an undersized box culvert with a full span bridge, achieving similar ecologic and community benefits as the Santa Ana Bridge replacement. The planning for this component is moving forward and we hope to be under construction in 2025. We anticipate comment periods for the Public Draft of the Matilija Dam Removal Environmental Impact Report in late 2023 and will need public support then. Along with public comment periods for California Environmental Quality Act (CEQA) public scoping for the Camion Cielo Bridge Project, and all downstream flood protection modification projects, we also will need state agencies, elected officials, public stakeholders, local city and county government to clearly speak up for the public, state-wide, that we support this project and must continue to prioritize all components to move into implementation.
Potential for Removal
With no uncertainty, Matilija Dam is set to come down; with each of the construction projects downstream, we are creating the pathway to achieve total dam removal. Removing Matilija Dam will restore a free-flowing river from the headwaters to the ocean, re-establish access for steelhead trout to required habitat, revitalize a healthy, native ecosystem, and expand opportunities for outdoor recreation. Ventura County officially made the decision in 1998 to officially remove the dam. In March 2016, the group overseeing design alternatives voted in favor of a removal plan. The approved alternative will use two bore holes at the base of the dam to remove and transport the impounded sediment. This concept represents a “natural transport” alternative that concentrates the downstream movement of the built-up sediment during the first storm events that follow. This alternative will minimize ecological impact downstream and lower the overall project cost by reducing the need to truck material in and out of the reservoir. Current projections estimate that once the bore holes are opened, complete dam removal and a free-flowing river will be achieved in two to five years.
Voice of Matilija Dam
