Petaluma neighborhood nervous about more rain after atmospheric river caused flooding

With rain in the forecast, a Petaluma neighborhood is nervous about repeat flooding.

Residents next to a new freeway sound-wall say their yards became ponds, with water creeping to their doors, during last month's atmospheric river event.  

"We want the rain but we don't want it under our house, and on the patio and up into our house," said Julie Byron, who lives on Madison Street, along Highway 101 on Petaluma's west side.

"It's terrible, and a lot of us asked from the start, 'what are they going to do with the water?'"

The 26 foot sound-wall runs behind about 30 homes.

When heavy rain fell October 24, as many as 20 properties had some degree of flooding.

"All the neighbors are talking now and we're trying to coordinate sump pumps and sandbags and all that," said Rachel Thomas ,whose backyard was submerged in almost a half foot of water by the storms end.

"Everything back there got destroyed, our plants, our irrigation, it all came up," said Thomas, "and then the yard wasn't draining so the water sat there for two days."

Small rectangular drain holes were added to the sound-wall late in construction, Thomas said, but the contractor warned they were an after-thought and not ideal.

"The way it was worded to us was Cal-Trans messed up and this is our temporary fix so prepare for flooding."

And it came, worse than expected, with water gushing off the freeway through the holes and building up behind the wall, then surging along side yards all the way to the street in front.

"We've been waiting for 35 years for that wall to get built," said resident Dan Plumley, noting the wall replaced towering eucalyptus trees that were  messy and a fire hazard.

During the two-year construction project, people on Madison Street sacrificed privacy, shade, and yard space.

Now they realize the wall may cause water damage to their homes in a wet winter.

"I think it's just a big mistake and they don't know how to fix it," said Plumley, "because you can't make water run uphill and that's what they've got."

Cal-Trans spokesman Bart Ney confirms a design mistake was made, and that drainage must be re-engineered.

He notes, the wall is a joint project of Cal-Trans and the Sonoma County Transportation Authority, so there is shared responsibility.

"It's a design issue," said Ney, "and we've got our eye on it."

In the past two weeks, residents have seen a flurry of work on the traffic side of the wall: new trenching and what appears to be piping.  

But they wonder where run-off can be diverted.

"They'll probably want to drain it into the creek at the end of our street," said resident Dave Byron.

"That's fine and dandy but what will Fish and Game say about sending all the freeway water into a creek that feeds the Petaluma River?"

Ney says Cal-Trans needs permission from every resident to enter their property in order to re-survey and develop a permanent solution.

But with more storms ahead, residents worry about how long that will take.

"It's not fair," said Julie Byron, "and I'm not signing off on completion of this project until they fix those drain holes, because we shouldn't take the freeway water."

A few days of rain is forecast for the North Bay, beginning Monday.

"It's immediate stress and anxiety wondering if it's going to happen again," said Thomas.

"Hopefully it won't be that heavy and I know we need rain, but these little holes, they are not going to work."

The drain slots are spaced every twelve feet along the wall, and some residents plan to plug or block them if water pours in again.

Ney says Cal-Trans sent a pump truck to the street last time, and will do so again if necessary.