The small dam in Milliken Creek is a concern for residents in Napa, Calif., who are hoping to avoid a repeat of a devastating 2005 flood. Under the agreement, the dam should be dismantled in 2016 or 2017, and will cost more than $1 million, paid for by taxpayers, homeowners and the resort.
A small dam in Milliken Creek at Silverado Resort and Spa in Napa, Calif., is a big worry for dozens of homeowners who want to avoid a repeat of a devastating 2005 flood and the Napa County Board of Supervisors approved an agreement this week that should dismantle this potential flood-creating plug in 2016 or 2017, the Napa (Calif.) Valley Register reported.
The 1950s-era dam is a concrete shell filled with dirt that creates a small, seasonal reservoir for irrigation. It has a corrugated steel culvert with a gate valve to allow stream flow when desired and carries a golf course road over the creek. Modest as it is, removing the dam and doing associated work will cost more than $1 million, in part because of the need to replace that dam-top road, county officials said. Under the new deal, the money will come from a combination of taxpayers, homeowners in the flood-threatened neighborhood and the resort, the Register reported.
As a bonus, removing the dam will allow steelhead trout to swim upstream. “What we’re aiming for is a combination of flood reduction and the removal of that fish passage barrier,” said Richard Thomasser of the Napa County Flood Control and Water Conservation District.
The monster 2005 New Year’s Eve storm and associated floods inspired the project. That night, water backed up behind the dam and flowed through the golf course into the Kaanapali Drive neighborhood. Water also swamped the neighborhood from Milliken Creek. A Napa Valley Register story after the event described water and mud hammering dozens of homes from both sides, the Register reported.
Linda Sheehan moved to Kaanapali Drive after that flood, but she’s heard the horror stories. Big rains send her online to check out the creek flow levels. “We’ve had this drought for the past few years and it hasn’t been a big worry,” said Sheehan, who is president of the neighborhood homeowners association. “This year, it’s a big worry; an El Nino year.”
She and 53 other Kaanapali Drive neighborhood households will each pay a $4,500 assessment in three payments to help address the problem. Sheehan said the expense is “definitely worth it.”
The project will protect more than 50 homes from flooding in a 100-year storm, a San Francisco Bay Regional Water Enhancement Program report said. On the negative side, the dam’s removal will also remove the road that carries vehicles over Milliken Creek for the golf course. Thomasser said the access needs to be replaced. “It’s the only truck-suitable bridge the resort has,” he told the Register.
Before the dam can go, Silverado will build a bridge over Milliken Creek for the road, Thomasser said. The bridge won’t impound water. Silverado could still exercise its water rights through such methods as having infiltration galleries—which are similar to wells—next to the stream, the Register reported.
Silverado will pay for the Milliken Creek bridge. Napa County will remove the dam, restore stream habitat and build a floodwater-carrying bypass swale in part by using the $500,000 state grant and $185,000 in local Measure A flood control sales tax dollars, a county report said.
Through the assessment, Kaanapali Drive homeowners will contribute $243,000 toward the project. The county will use $58,000 for its project costs and $150,000 to pay Silverado for the loss of stream crossing access resulting from the dam removal. The homeowners association will keep the remaining $35,000 for administration and insurance, the report said.
Design work for the project is to be completed in 2016. When the project begins depends on Silverado resort building the bridge and on state and federal agencies granting the necessary permits, the Register reported.