MMWD seeks state grants for dam upgrades

The Marin Municipal Water District is seeking $4 million in grants to fund two of its dam projects.

The district board unanimously approved two grant applications for the state Department of Water Resources’ safety and climate resiliency program. The grants would give up to $2 million for each project.

The funds would go toward repairing spillways at various dams and replacing valves and actuators at Phoenix and Lagunitas dams. Actuators help control water flow.

“This opportunity for the submission of these proposals seems like it’s quite new, or this is a new program focused on the maintenance of dams that predate a certain period,” Ranjiv Khush, the board president, said at its meeting on Oct. 15. “It’s a great opportunity that’s come up from our department resources and I was really excited to see that we jumped on it.”

The grants would not cover the full cost of the projects, according to Adriane Mertens, a district spokesperson. The valve and hydraulic actuator project at Phoenix Lake is estimated to cost around $5 million because of its complexity, Mertens said. The cost of the spillway project is pending.

“However, we anticipate that repairs or improvements to sub drainage or potentially localized structural concrete repairs would be costly,” Mertens wrote in an email.

The district has spillways at its Peters, Seeger and Soulajule dams. In 2017, after the failure of the spillway at the Oroville Dam in Butte County, the state Division of Safety of Dams ordered dams across the state be evaluated. The spillway repair project is a result of the district’s spillway condition assessments and are part of a dam safety requirement.

In the first phase of its spillway evaluation, completed in 2019, the district repaired minor and surface-level issues. Phase one repairs involved spalls, surface defects, offsets, sub-drain cleaning and crack and joint sealing.

Now in phase two, the utility is conducting a deeper structural evaluation of spillways, using imaging techniques like ground-penetrating radar to investigate their integrity.

Additionally, the aged valves and hydraulic actuators need to be replaced. The work is part of the district’s five-year capital improvement plan.

“While the Districts dams are safe and meet all state safety standards, these projects will help to keep the dams in good operating condition for the future,” Mertens wrote.

Board member Monty Schmitt asked if the replacement valves would allow the district to adjust how much water is released.

“I know right now part of the issue, at least with one of the valves, is that it leaks and it’s old, probably both of them,” Schmitt said.

Alex Anaya, the district’s engineering director, said the project would allow the valves to be left partially open if desired. However, the main goal of the project is to fix the leaking valve and allow the district to open and close the valves remotely.