USACE begins improvements to Folsom Dam Dikes 1-6

U.S. Army Corps of Engineers Sacramento District
Published Sept. 22, 2023
A scraper drives on top of an earthen dike with green trees, residences, and a lake in the background.

Dike 8, on the southern bank of Folsom Lake, was raised 3.5 feet during the first half of 2020.

The U.S. Army Corps of Engineers Sacramento District has begun site preparation at Folsom Dam Dike 1 in Granite Bay, California, so contractors can raise the site up to 3.5 feet as part of the Folsom Dam Raise project.

The prime contractor for Dikes 1-6, Maloney-Odin Joint Venture, has placed security fencing and begun clearing and grubbing work on the Dike 1 site. Fenced areas onsite are closed to the public, but the dike will remain passable for pedestrian and bicycle traffic, with some limitations.

As part of the construction, Park Road atop the dike will be demolished one lane at a time. Starting with the upstream lane, the asphalt will be removed and the dike raised up to 3.5 feet. Once the upstream side has been raised and repaved, traffic will reopen on that side, and the process will be repeated on the downstream side.

Throughout the construction process, Park Road at Dike 1 will be limited to alternating one-way traffic using mobile traffic signals.

There will be impacts to trails along Dikes 1-3 including partial or complete closures during construction. USACE is working to minimize disruption and create a plan that maintains limited trail access. More updates on these trails will be available on the district website and social media during construction

Parking lots and boat ramps will remain open to the public during construction. The access road north of Dike 3 (Stage 4 North) will be temporarily closed, but visitors will be able to use the access point on the right past the entrance kiosk (Stage 4 South). At Dike 2, the current access point will be permanently blocked and replaced with a new access point.

Construction near Dike 5 is set to begin within the next month as the contractor sets up the staging area. The trail downstream of Dike 5 will be slightly detoured, but the bike lane on the east side of Folsom-Auburn Road will remain open.

The construction work on the dikes is scheduled for completion in summer 2025.

Modifications to Dikes 1-6 are part of the Folsom Dam Raise project, an ongoing joint effort of USACE, the Bureau of Reclamation, Central Valley Flood Protection Board, California Department of Water Resources, and the Sacramento Area Flood Control Agency   that will allow for greater control of releases from the dam during large flood events. The purpose of the project is to reduce overall flood risk for the Sacramento area.

Other components of the Folsom Dam Raise project include Dike 8 (completed in 2020), Dike 7, left and right wing dams, Mormon Island Auxiliary Dam, and the main dam itself. All of these components are set to be raised up to 3.5 feet, with the project scheduled for completion in 2027.


Jeremy Croft
916-717-4096 (cell)

Release no. 23-029