January 4, 2006

By COREY YOUNG
ARGUS-COURIER STAFF

The floodwaters that swept through northern Petaluma last weekend surprised city officials, who didn't expect heavy rainfall to pose such severe problems for businesses and residents in that area.

"This water went where we never dreamed it would go," Mayor David Glass said Monday after a weekend storm dumped more than seven inches of rain on the city.

The downpour swelled local creeks and the Petaluma River, which crept into parking lots and buildings at the outlet mall on Petaluma Boulevard North, car dealerships near Industrial Avenue and shopping centers on North McDowell Boulevard.

Residents of four mobile home parks were told to leave after nearby creeks overflowed, flooding cars and roads. Residents of Leisure Lake Mobile Home Park north of Petaluma were cut off when Stony Point Road flooded, requiring firefighters to cut down a fence along Highway 101 and load seniors onto buses parked on the freeway.

It was an unexpected scene that contrasted sharply with the Payran Street neighborhood further south, where a half-dozen prior floods, beginning in 1982, have spilled into homes and caused major damage between Lakeville Street and Jess Avenue.

But this time, Payran residents simply watched as the muddy brown river rolled through a $41 million flood control project that is nearly complete.

City Councilmember Pamela Torliatt said the city prepared to evacuate the central Petaluma neighborhood, but the thick concrete floodwalls recently built along the river held the waters at bay.

"Thank goodness we had the flood control project in," Torliatt said.

"The water level rose to the highest we have ever seen in the flood control channel, but we still had about five feet before it reached the top of the floodwall," said Mike Ban, the city's director of water resources and conservation. "The flood control project worked as designed."

He added, "If this were '98 or one of the years before the channel was built, Payran would have been under water."

But the upper reaches of the river that flooded may pose new trouble spots to watch in the future, Ban said.

"That's an area where we haven't seen a problem in a long time," he said. Engineering Manager Dean Eckerson took aerial photos of the flood from a helicopter Saturday and after cleaning up, the city plans to study how and why the northern sections of town flooded.

Glass said he's asking residents to send him photos of their flooded homes, streets and businesses.

"I'd like some kind of a record of who flooded," he said.

The city will now begin using data, photos and video to determine why the river and creeks flooded where they did, officials said.

Some theories have been raised, but so far there is no clear answer.

Fire Chief Chris Albertson said he suspects overgrown brush in the river channel between Corona Road and the outlet mall may have caused water and debris to back up, but that's based only on his own eyewitness account.

He saw fast-moving water passing under the Corona Road bridge, but further down Petaluma Boulevard North, the flow slowed to more of a "meandering stream" at the outlet mall, he said. Overgrown brush in that area Ñ which is maintained by the county Ñ may have been a factor, but there are other concerns, he said.

"It was just a lot of water in a short period of time," Albertson said. "We had flooding this time in locations that, historically, have not been an issue in the past. These are the things we are going to look at moving forward."

Glass said the city needs to know as much as possible about why the area flooded and "needs to take the most conservative approach" to future development in the area.

Standing on the road to the outlet mall Saturday, he said he saw "raging, rushing water" going by.

"There's no greater argument that flooding is a danger" in the upper reaches of the river, he said, adding that he expects the weekend's flood to rekindle the debate over building in the floodplain. Opponents of expanding the outlet mall and building the Rainier crosstown connector have claimed the projects could lead to more floods in the area.

Torliatt, too, decried future building in the area and said the flooding shows that much of the land near the outlet mall is unsuitable for development.

The city is negotiating to buy 16 acres formerly planned for an expanded outlet mall and now being eyed for open space. Further north, a new car dealership is planned on Industrial Avenue, while a shopping center expansion is still proposed on the south side of the outlets.

"We're seeing exactly what is going to happen again and again and again when we have these kinds of storm events," Torliatt said. "What we saw upstream is going to be status quo or worse if we build in the floodplain."

She said when the city lays out its updated general plan this spring, identifying property in that area for expanding the floodplain should be a priority.

"I hope the council will take heed of the results we have seen from this storm," she said. "We already know what the history is -- we just saw it."

Councilmember Mike Healy said the city has been diligent in gathering data about the storm and its aftermath "to go back and analyze this and figure out what happened and why."

That will also allow the city to update its flooding projections in the new general plan, he said.

The amount of brush in waterways and the impact of a constriction fence, or weir, at the entrance to the flood control project will also be examined, Healy said.

The weir constricts water flow as it enters the flood control channel, slowing the flow so water does not erode the banks.

Healy said he would not speculate on whether brush, development or something else caused the weekend's flooding before the city completes its studies.

"There are no sacred cows," he said. "Everything's on the table, everything should be looked at, but I'm not going to jump to conclusions before we have all the facts."

While the flood control project near Payran appeared to work well, it is not yet complete, and city officials are trying to get the local railroad agency and the U.S. Army Corps of Engineers to remove a railroad bridge near Lakeville Street as soon as possible. The removal of the bridge is one of the last major pieces of the project still unfinished.

However, the removal of the bridge is delayed because SMART, the Sonoma Marin Area Rail Transit district, is not cooperating with the same urgency as the city, a source said. The city wants the bridge removed as soon as possible because it can restrict the flow of water and trap large pieces of debris, blocking up the river.

As the floodwaters receded earlier this week, city officials said there is no official damage estimate for Petaluma. Inspectors will be out studying losses at businesses, residences and city property and an estimate will be made soon, the city said.

The flooding prompted the city to declare an emergency Saturday morning and request aid from county, state and federal agencies, and top officials gathered in the police station's emergency operations center to monitor river levels and plan emergency response.

Crews started working after 8 p.m. Friday night and worked "around the clock" cleaning up debris, clearing drains and re-opening roads, officials said.

Police set up barricades and stationed officers on North McDowell Boulevard and Old Redwood Highway when those streets flooded Saturday, but some drivers drove around the roadblocks or ignored officers and had to be rescued by the fire department, Lt. Joe Edwards said.

"People said, 'Well, these signs obviously don't apply to me,'" Albertson said. "They drive down the road, it's muddy water, they can't see the road and they drive into deeper water. We had people who were not thinking clearly."

The southbound right lane of Highway 101 near the top of the Cotati Grade will probably be closed for several days after a 75-foot section of saturated ground under the road started slipping Monday, said Officer Christine Jacobs of the California Highway Patrol.

Several drivers reported that the saturation caused their vehicles' tires to blow out. The CHP originally hoped that the lane would be open for the Tuesday morning commute.

Early Saturday morning, around 6 a.m., Petaluma officials feared that a boat that came loose from its dock in the Turning Basin downtown would float away and collide with the D Street bridge, but quick action by workers and a barge operator from Jerico Products prevented disaster.

If the boat became stuck under the bridge, it could have created a dam and backed water up into the downtown, Glass said.

He said officials kept their eyes on Leisure Lake Mobile Home Park, traditionally one of the first places to be threatened by rising water, but were surprised by the extent of flooding at the Petaluma Auto Plaza and other businesses in the Petaluma Boulevard North-Old Redwood Highway area.

The parking lot at the Redwood Gateway Center -- home to Kohl's and Pier One Imports -- flooded, along with car dealerships at the auto plaza. The outlet mall was closed Monday while merchants cleaned up from over a foot of water in their stores.

Rich Gustafson, who owns Rich's Auto Body on Petaluma Boulevard North, was one of the first on the scene at the auto plaza, where he used his oversized tow truck to ferry dealership employees through four to five feet of water to their car lots.

"It came up pretty fast, pretty high," he said.

They moved cars to "the highest ground we could" even as Gustafson's own business was invaded by the rising river.

He lost an estimated $20,000 in equipment and computers and estimated that North Bay Nissan and Victory Chevrolet lost a total of 180 cars, including 143 used vehicles.

"If we hadn't moved those cars, those dealerships would have lost millions of dollars in cars," he said.

Across the freeway, the Petaluma Plaza and the Plaza North Shopping Center were inundated with water from nearby Washington Creek. As the creek overflowed its banks between East Washington Street and Petaluma Plaza, it poured mud, debris and even fish into the two shopping centers' adjoining parking lots.

Stores including Big 5 Sporting Goods, Silver Screen Video and Kmart were flooded. Kmart employees piled bags of cat litter and fertilizer at the door to keep out the water rolling in from the parking lot.

"Kmart had a couple of inches of water in the whole store," said Plaza North property manager Craig Woolmington. "They had extensive inventory damage."

Half the parking lot was underwater Saturday and large sections of parking spaces were still roped off Monday afternoon.

"It brought all the debris up just like a tidal surge," Woolmington said.

He suspects that overgrown weeds in Washington Creek and the large surge of water combined to cause the spillover into the shopping centers. The property backs up to Highway 101 and the creek flows under the freeway.

"We think it just blocked up there and couldn't get through fast enough," he said. "The volume of material couldn't get under the freeway."

The shopping center is 27 years old and has never flooded before, he said. Maintenance employees spent the weekend cleaning up and just washing off the sidewalks outside the stores cost $10,000, he said.

But on Monday, Woolmington said he received good news from the Petaluma Fire Department, which offered to send over a water pumper to help clean the mud out of the parking lot.

(Contact Corey Young at cyoung@arguscourier.com)

PETALUMA'S FLOOD HISTORY

This past weekend was the eighth time the Petaluma River has flooded since 1982. Some of the major flood events occurred in: