Thursday, April 27, 2006
Finally, the public has an opportunity to comment on the nearly useless—albeit dangerous—San Clemente Dam on the Carmel River.
Late last week, a draft environmental impact report on the seismic safety project for the dam was released by the state Department of Water Resources and the US Army Corps of Engineers.
The Department of Water Resources’ Paula Landis says the 85-year-old dam is a hazard and should have been fixed years ago.
“In the event of a maximum credible earthquake or a probable maximum flood, we believe the dam is unsafe and must be remediated,” she says.
Located at the confluence of the Carmel Valley River and the San Clemente Creek, nearly four miles southeast of Carmel Valley Village, the San Clemente Dam was tagged as one of the state’s most dangerous dams by the California Division of Dam Safety in 1986. In 1992, the CDDS ordered its owner, the California-American Water Company, to make expensive safety improvements.
Today, 14 years later, the environmental impact report marks the first significant step towards improving the safety of the dam. Settling on a solution may prove more difficult.
Over the decades, the dam has been choked by an estimated 2.4 million cubic yards of sediment. It now holds less than 10 percent of its original water capacity. In addition, the dam severely impacts the resident steelhead trout population, which was placed on the federal endangered species list in 1997. Environmentalists want to see the dam taken out.
The seismic safety report evaluates five alternative projects, ranging from removing the dam altogether to doing nothing at all. Cal-Am officials say removal plans cost too much, and would hurt ratepayers unless the project was heavily subsidized.
Cal-Am’s preferred alternative is a plan to thicken the dam with concrete.
Another option is the “dam notching alternative.” The dam’s existing gates, piers and walkway would be demolished and then a large notch would be cut down the center of the dam. This would allow the accumulated sediment to be removed and transported for offsite disposal.
The report also includes two potential plans for removing the dam. The first would simply demolish and remove the dam. All sediment would be transported to a downstream disposal site. But this option may flood the river with sediment and destroy habitat and wildlife.
Consequently, environmental groups such as the Coastal Conservancy and the Carmel Valley Steelhead Association support the “reroute and dam removal alternative,” which would create a diversion channel to reroute the river. One-half mile of the river would be bypassed and used to store the accumulated sediment. Once the sediment is stabilized then the dam would be demolished and removed.
The reroute and removal plan has won strong community support, and has the backing of former state Sen. Bruce McPherson, Assemblyman John Laird and County Supervisor Dave Potter.
FOR A COPY OF THE DOCUMENT, call 559-230-3323. the review period, which ends June 20, will include a public meeting at Rancho Cañada on May 23.