Removal of the 90-year-old Rindge Dam from Malibu Canyon—a long-anticipated, multi-million-dollar project—moved a crucial step closer to reality on Friday, Nov. 13, when the U.S. Army Corps of Engineers (USACE) announced the project’s report was signed and sent to congress for funding.
Lt. Gen. Scott A. Spellmon, USACE commanding general and 55th U.S. Army chief of engineers, signed the Malibu Creek Ecosystem Restoration Chief’s Report on Friday, “progressing the project to Congress for authorization,” according to a USACE social media post.
The signing comes more than two years after the California Coastal Commission approved the plan, in March 2018. At the time, the project was expected to begin in 2025.
The plan, which can be viewed here, calls for the removal of the aged dam, in addition to 780,000 cubic yards of sediment which will go toward landfills as well as “reuse in near-shore habitat,” the USACE post stated, with sand trucked to the Ventura Harbor and then loaded onto barges for distribution along the Malibu coast east of the Malibu Pier. The plan was estimated to cost $279 million, resulting in 525 acres of habitat restored ($532,000 per acre). The dam’s removal is expected to restore 18 miles of habitat for Southern California Steelhead Trout, a federally endangered species. The plan also calls for eight “partial aquatic upstream habitat barriers” to be removed or modified in tributaries to Malibu Creek.
Costs for the project would fall on both the federal government ($172,249,000, making up 62 percent of the cost) and the California Department of Parks and Recreation (State Parks), which would pay 38 percent, or $106,960,000. Over the five years following the project’s completion, there would be an additional $9,403,000 cost for monitoring.
The 100-foot-tall dam, which is not functioning, is a popular hiking destination within Malibu Creek State Park, despite being off-limits, and has been the site of several serious injuries in recent years, especially after it gained popularity on social media. Most recently, a Los Angeles man fell to his death from the top of the dam in June 2020.
According to the report, the project is expected to take seven years to complete, with various project alternatives offering anywhere from 39 to 139 truck trips per day during the construction period, varying by year.
Malibu city officials and residents of the downstream Serra Canyon neighborhood have voiced concerns, including at the 2018 California Coastal Commission meeting, about the likelihood of flooding to the neighborhood during and after the removal of the dam. The report explores the flood risk for downstream communities, with the word “flood” appearing more than 600 times in the 615-page document.
“If not handled properly, dam removal can pose a substantial though temporary flood risk resulting from the downstream movement of sediment and the associated potential for increased flooding or damage to existing habitat,” the report acknowledges. However, the report suggests that because the Rindge Dam is no longer collecting sediment, flood risk to the area would increase were the dam to not be removed.
According to the report, were the army corps to take no action, “More coarse-grained sediment will be transported beyond Rindge Dam than prior decades and will deposit in downstream reaches raising the elevation of the channel invert. This will increase the risk of flooding to downstream residences and commercial structures as the system recovers from the impact of dam construction 90 years ago.”
