Award: Dam seismic retrofit project
Value: $1.88 billion
Location: Santa Clara County, California
Client: Santa Clara Valley Water District
A California dam that faces threats from major earthquakes will soon receive upgrades.
The Santa Clara Valley Water District awarded a $1.88 billion contract to a JV of FlatironDragados and Sukut to complete the Anderson Dam Seismic Retrofit Project, according to a Tuesday announcement. The overall project will cost $2.8 billion.
As part of the project’s scope, the construction team will rebuild most of the dam and spillway, install new outlet pipes and complete other major safety upgrades, per the announcement. Construction is expected to begin in 2027 and take seven years to complete.
Valley Water has completed most of the preparatory projects to rebuild the dam, per the announcement. At the center of that effort is the Anderson Dam Tunnel Project, which replaces the dam's existing 4-foot-diameter outlet pipe with a 13-foot-diameter outlet and is expected to finish later this year.
Anderson Dam, which was originally built in 1950, sits next to Anderson Reservoir, the largest of Valley Water’s 10 reservoirs. The reservoir is big enough to hold the contents of the other nine within it, according to the water authority. However, it has been severely limited by safety issues, and Anderson Reservoir is only operating at 3% capacity as a result of seismic concerns, per Valley Water.
In 2017, water overflowing from Coyote Creek, which the dam regulates, contributed to widescale flooding in the San Jose region. That was the same year heavy rains led to a massive hole developing in the concrete spillway for Oroville Dam, which, like Anderson, is an earthen embankment structure. The eventual repair costs topped $1 billion.
Today, authorities have a storage restriction of about 55 feet below Anderson Dam’s crest to protect the public in event of an earthquake, per Valley Water.
The Anderson Dam’s project progress has been delayed in the past, according to The Morgan Hill Times. Matt Keller, media & public relations supervisor at Valley Water, told Construction Dive via email that delays were the result of the federal environmental process, including the National Environmental Policy Act’s process for an environmental impact statement.
“Rebuilding Anderson Dam is our top priority,” said Tony Estremera, Valley Water board chair, in the announcement. “This milestone reflects years of hard work, collaboration, and perseverance by our staff, contractors, regulators, and community partners.”
The Anderson Dam project gains momentum as water projects across the country have surged throughout the year. The appetite for water jobs will only grow as the Water Resources Development Act, which passed the House Committee on Transportation and Infrastructure earlier this summer, promises $30.5 billion for these types of projects.
The JV contractors — FlatironDragados and Sukut Construction — also have a history of collaboration. The firms worked together before Flatiron and Dragados merged in 2024 on the Lake Isabella project in Kern County, California.
