The Problem

Rindge Dam altered the natural geomorphic, riparian and aesthetic character of Malibu Creek. The dam has trapped over 780,000 cubic yards of sediment that was naturally destined for the coastline, where it would support beach nourishment and prevent coastal erosion. Having completely filled with sediment less than 30 years after being built, the dam was rendered defunct over 64 years ago.

Since the dam’s construction, federally endangered Southern California steelhead have been blocked from reaching high-quality spawning grounds in upper Malibu Creek, which is designated critical habitat for this steelhead species. The dam prevents steelhead from accessing more than 18 miles of historical spawning and rearing habitat in Malibu Creek and tributaries.

Current Situation

The watershed represents a unique opportunity for systemic and sustainable ecosystem restoration in highly urbanized southern California. Rindge Dam was deemed obsolete due its lack of function as a water storage facility and has been the subject of removal planning for decades.

While there is very little disagreement about the need for removal, progress has been slow given the multiple agencies and organizations involved in the planning. The dam removal process was formalized when the U.S. House of Representatives commissioned the “Malibu Creek Ecosystem Restoration Feasibility Study” in 1992, requesting a solution that improved the Malibu Creek watershed and the Malibu shoreline. The Army Corps of Engineers led this study to investigate ecosystem restoration opportunities within the Malibu Creek watershed, to improve aquatic and riparian ecosystem habitat connectivity and restore more natural sediment transport to the coast.

Working with the Army Corps, the Locally Preferred Plan (LPP) promoted by California Department of Parks and Recreation is the preferred alternative for dam removal. That alternative, described in the Feasibility Study completed in January 2017, calls for removal of the concrete arch dam and spillway, removal of upstream smaller fish passage barriers, and removal of the impounded sediment using traditional mining methods and various deposit locations for that sediment. The impounded sediment, an estimated 276,000 cubic yards, would be placed along the Malibu shoreline or nearby areas.

Potential for Removal

The removal plan for Rindge Dam was approved by the California Coastal Commission and California Department of Parks and Recreation. The project is nearing completion of the environmental review phase initiated in 2000 pending release of the final Feasibility Report by Army Corps of Engineers and review by National Marine Fisheries Service.

Trucking the impounded sediment to its end destination is the time-consuming and tricky piece of this dam removal project. Some would be trucked up Highway 101 to Ventura Harbor about 41 miles away from the dam and placed on barges for transport to the Malibu shoreline. Nearly two-thirds of the impounded sediment would be trucked from the impounded sediment site to a local landfill. The timeframe to transport all the sediment is estimated at 8 years due to seasonal construction and daily trucking restrictions. Total cost estimate is $187 million, with significant cost savings if sediment transport costs can be economized.