The Cupertino Courier

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Flood protection on Permanente Creek

By Cody Kraatz

The Santa Clara Valley Water District recently announced plans to protect 3,000 homes in Los Altos and Mountain View from a "100-year flood" of Permanente Creek.

Such a flood, which has a 1 percent chance of happening in any given year, could cause $48 million in damage. When the project is completed, residents in the flood plain would no longer have to pay for flood insurance.

Water district officials, at aMarch 6 Cupertino City Council meeting, proposed digging a "detention" basin along the creek in Rancho San Antonio County Park to hold the overflow of water from such a flood. The creek last flooded in 1998.

The park is one location among several alternatives that include detention sites at Mountain View parks, concrete floodwalls and bypasses under Springer Road in Mountain View.

"Finding significant, large enough undeveloped parcels downstream is difficult,'' said Afshin Rouhani, a civic engineer with the water district. "The more upstream you put it, the better it is, too."

The plan calls for a 15-foot-deep basin on an eight-acre parcel near the creek, while the water district would replant the area with vegetation. The area would become habitat for the endangered red-legged frog, said Beau Goldie, the district watershed manager.

The water district expects construction to begin between 2010 and 2016. The project is not fully funded yet, but can draw from Santa Clara County's $27 million Clean, Safe Creeks measure that was passed by voters in 2000. State and federal flood and environmental protection grants are other potential sources.

"Our area is impacted by this," said Cupertino Councilwoman Dolly Sandoval, referring to the Oak Valley neighborhood. "I think having some representatives from Cupertino on the alternatives selection committee would be helpful for us."

Some Cupertino residents who live near the park would be affected during construction, which would take about one year, because trucks would carry tons of dirt out of the park from the project site.

Councilman Richard Lowenthal asked for more detail later on.

"I would urge that, when it comes time to vote on alternatives, that you be more definitive on what the benefit will be. It's good for us to be able to commit something to our residents," he said.

The water district has already held seven public meetings in Los Altos and Mountain View. They were very well attended because people wanted to know what the project would entail and how it would affect them personally, said Rouhani.

Before construction can begin, all the cities and the county have to be on board, and the city managers involved need to arrange for a project scoping meeting, as required by the California Environmental Quality Act. The public will have the chance to speak at that meeting, which will likely be held in May.

The project entails not only flood protection, but also trail improvements and environmental protection. The water district has asked the county to point out what sort of trail work might be needed. The Clean, Safe Creeks measure had an environmental focus and called for trails along creeks.

The district is definitely looking into trails, "cooperating with the local agencies and getting the best value for the public," said Rouhani.

"The district's mission used to be just flood control and water supply," he said. "They added environmental protection and stewardship a couple years ago."

For more on this project and others, go to www.heynoah.com and search for Permanente Creek.