12:30 p.m.Construction schedules for two elements of the Napa River flood control project are about to collide, resulting in an overlapping two-and-a-half-month shutdown of both First Street and Third Street east of Soscol Avenue.

Flood control has snarled traffic before — most memorably, two 80-hour closures of Soscol Avenue in 2003 and 2005 — but nothing like what is expected to confront motorists in early 2009.

For two and a half months, cross-town traffic will need to find an alternative to First and Third between Soscol and Silverado Trail. These east-west connectors today carry some 13,000 vehicles a day.

Representatives of the Napa River flood control project and the city’s Public Works Department delivered the bad news at Thursday’s Traffic Advisory Committee meeting.

“Wow, this is going to be interesting,” said Councilman Jim Krider.

Councilman Peter Mott feared that the dual closures would slow fire engines, leaving Alta Heights residents in jeopardy in a fire or medical emergency.

Fire Chief Tim Borman appeared stunned by the news, as well. “We’re going to have to meet with somebody and go over this in detail. This poses problems,” he said.

The city and the flood control district have commissioned a $50,000 report on how to handle traffic during this perfect storm of flood control construction.

Motorists will be encouraged to detour around the twin construction zones, using Lincoln Avenue to the north and the juncture of Silverado Trail and Soscol to the south.

Some drivers will be able to jog around the Third Street closure using Sixth and Burnell streets near the Napa Valley Exposition, but these side streets won’t be able to carry the full load, said Farid Javandel, the city’s senior traffic engineer.

The city of Napa Fire Department may want to consider stationing an engine on the east side of the river during the closure overlap, Javandel said.

Another solution, Borman said, may be to respond to calls in Alta Heights from the station behind South Napa Marketplace rather than from the downtown station.

Making tracks

The dual closures are occurring because two elements of the flood control project, each on its own funding and planning track, will collide in early 2009, officials said.

In June, the city will close First Street for 14 months so the bridge over the Napa River next to Copia can be replaced with a higher span that will not obstruct flood water.

In late October, a contractor for the U.S. Army Corps of Engineers will begin a multi-year project to elevate Napa Valley Wine Train tracks east of downtown. This will involve building two railroad bridges, one over the Napa River, the other over a planned flood bypass channel.

As things look today, Third Street will be torn up starting in late December or early January for two and a half months so new track, elevated five feet, can be laid across Third, said Julie Lucido, the local flood district engineer.

The old tracks, which will remain in use for at least several more years, will be elevated two feet. The 30-foot distance between old and new tracks will be elevated as well, Lucido said.

The conflicting construction timetables are driven by the availability of funding as the $300 million flood control project works its way through central Napa, officials said.

Both the replacement of the First Street bridge and the railroad relocation are occurring later than first planned. In theory, the closures of First and Third could have occurred earlier, Lucido said.

It was only this winter that the city and the flood control district realized that there was no avoiding the overlapping closures, city Public Works Director Mike O’Bryon said.

That’s when the traffic mitigation study was commissioned. “By planning we can minimize the impact,” he said.

Barry Martin, the city’s public outreach coordinator, said it’s not a sure thing that the overlap will occur in January rather than later in 2009 — or that it will happen at all.

The history of the flood control project is one of delays caused by inadequate federal funding or contractors who propose schedule revisions, Martin said.

“My approach is wait and see. It’s too early to get overly concerned about it,” Martin said. “The railroad contract is a big animal with a lot of moving parts.”

The Army Corps of Engineers will be awarding contracts for railroad relocation estimated to cost $45 million. The current schedule calls for this work to wrap up in September, 2011, but that assume $15 million a year in federal funding.

If funding is less, the project will take extra years, Lucido said. This year’s federal allocation was $10.8 million. President Bush has proposed $7.4 million next fiscal year.

In support of flood control, the city is replacing the First Street bridge over the river. Most of the estimated $13.9 million cost is coming from another federal source.

Assuming that the overlapping closures occur early next year, motorists can expect another two-and-a-half-month closure of Third Street two years later, Lucido said. That’s when the contractor will be removing the old Wine Train track, which will remain in use until then, she said.

Fortunately, the replacement bridge on First will be finished, so only one east-west thoroughfare will be closed at that time, she said.

In early 2010, according to the current schedule, First Street will be closed for three months so the tracks just east of Soscol can be elevated five and a half feet, Lucido said.

In mid-2010, the final disruption will happen: Soscol Avenue will be completely closed for at least several days so the tracks across Soscol can be raised between two and three feet, she said.

This closure will be closer in length to the 80-hour shutdowns in 2003 and 2005 rather than much longer disruptions being planned for First and Third, Lucido said.

With these closures, the worst traffic impacts of flood control will be over, Lucido said. Flood control will tackle Napa Creek after the railroad relocation, but road work will affect fewer people, she said.