The largest reservoir in Santa Clara County has been sitting at about 3% of capacity. That’s the number to hold onto while reading the rest of this.
Santa Clara Valley Water District awarded a $1.88 billion contract to a joint venture of FlatironDragados and Sukut Construction to execute the Anderson Dam Seismic Retrofit Project, according to a Tuesday announcement. Total project cost lands near $2.8 billion. Construction starts in 2027 and runs seven years.
What the Anderson Dam contract actually covers
The JV will rebuild most of the dam and its spillway, install new outlet pipes, and complete a slate of other safety upgrades. Anderson Dam went up in 1950 as an earthen embankment structure, and the seismic review that followed a decade of tightened standards concluded it couldn’t be trusted to hold a full pool through a major earthquake on the nearby Calaveras fault.
So Valley Water drained it. Authorities now enforce a storage restriction roughly 55 feet below the dam crest. Anderson Reservoir alone can hold the contents of the district’s other nine reservoirs combined, which makes the restriction an expensive piece of insurance in a county that imports most of its water.
The preparatory work is nearly done. The Anderson Dam Tunnel Project, which swaps the existing 4-foot-diameter outlet for a 13-foot one, is expected to wrap later this year. That tunnel is what lets crews control the reservoir during the rebuild.
Why the schedule slipped for so long
Valley Water spokesman Matt Keller attributed the delays to the federal environmental process, specifically NEPA’s environmental impact statement requirement. That’s a familiar story on large water projects, and it’s the reason a dam identified as seismically deficient in 2020 won’t see a shovel until 2027.
The 2017 flooding along Coyote Creek, which Anderson regulates, put 14,000 San Jose residents under evacuation orders. The same winter, a hole opened in the concrete spillway at Oroville Dam and repairs eventually topped $1 billion. Both events sit behind the current standards.
A JV with a track record on the same kind of work
FlatironDragados and Sukut aren’t new partners. The two worked together on the Lake Isabella dam project in Kern County before Flatiron and Dragados merged in 2024. Both firms self-perform heavy earthwork and concrete, which matters on a seven-year embankment job where subcontracting the core scopes would introduce schedule risk nobody wants.
The award lands in a water market that keeps getting deeper. PG&E just handed Granite Construction a $50 million spillway replacement at Tiger Creek Regulator Dam in Amador County, and Sundt recently closed out the $34 million Upper Brushy Creek Dam 101 near Round Rock, Texas. The Water Resources Development Act, which cleared the House Transportation and Infrastructure Committee this summer, would put another $30.5 billion behind projects of this type.
Seven years of construction means a crew on that hillside until 2034. San Jose gets its reservoir back a year after that.