California Coast & Ocean

Just about everyone who knows about Matilija Dam on Matilija Creek in the Ventura River watershed agrees that it should be taken down. Now a project is moving forward that promises to make it happen. A highly unusual degree of consensus has been reached on how to dismantle the massive concrete structure 15.6 miles upstream from Surfer's Point. A feasibility study has been done; federal and state environmental documents have been completed without challenges; the final design process has begun. In October 2005, the Ocean Protection Council committed $2 million for pre-engineering and design.

"A lot of environmental issues seem abstract--wetlands, for instance," said Paul Jenkin, coordinator of the Matilija Coalition, an alliance of community groups, businesses, and individuals committed to restoring the river system, starting with deconstruction of the dam. "But people get excited about a huge piece of concrete blocking the river, which could be removed."

In 1947, when the Ventura County Watershed Protection District (then the Flood Control District) built the dam at a favorite fishing spot on Matilija Creek, just above the point where it joins with North Fork Matilija to become the Ventura River, the builders knew it would not be useful for long. Sue Hughes, legislative analyst for the County, says a recently found memorandum from the District, written in the late 1940s, makes that clear. "When they pencilled it out--the cost of building the dam, the cost of supplying water--they knew it would only be 34 to 36 years before it filled with sediment. However, they concluded that the dam was the most cost-effective way to provide water for agricultural and residential use."

Now it's been years since the dam lost its flood control function, and its water storage capacity is barely worth mentioning. Designed to store 7,000 acre-feet, it holds less than 500. Current estimates show that its storage capacity will be zero by 2020. "Directly behind the dam we have a 140-foot-deep hole filled with two million cubic yards of mud," said Jenkin. "Stretching almost a mile upstream of that, the dam has trapped another four million cubic yards of sand, gravel, and cobble, sediment once destined to flow down the river to the beach."

What Matilija Dam continues to do to this day, however, is to kill life in the river, erode the riverbanks, and tear up the ocean shore. The dam has choked off passage to steelhead trying to reach their spawning grounds, and caused sediment-starved "hungry" water to carry away the wide beach that was once at Surfer's Point. "I grew up here. I have to tell you, the beaches here in the late '60s had hundreds of yards of sand," said Hughes.

Without the cushion of sand to protect it, the shoreline was subjected to such severe wave attacks that concrete barriers have been built to keep a waterside trail and parking lot from washing away. The dam may also be a potential safety hazard, because its concrete face has cracked. Although it is inspected annually and has been declared safe for the next 50 years, some people worry that an earthquake or other extreme event could prove otherwise.