The city of Napa Public Works Department is of two minds about having a long, wet winter.

Heavy rains would help to fill local reservoirs, but if the rains come early they could set back construction of the First Street bridge over the Napa River.

“We’re keeping our fingers crossed for a dry November-December,” said Jason Holley, the engineer who oversees the project for the city. “It’s no fun building anything in the rain.”

If the rains kicked off fast and furious, the $15 million project might have to shut down for the winter, wrecking plans to reopen First to traffic in August, he said.

Fortunately, the California Department of Fish and Game has twice extended the deadline for completing the construction of the bridge foundation in the middle of the river, Holley said Monday.

The original deadline of Oct. 15 was moved to Oct. 31, and now to Nov. 21, assuming that Mother Nature doesn’t go on a rampage before then, Holley said.

Showers are predicted for this weekend, but they shouldn’t do more than knock the dust down, Holley said. The general contractor, American Civil Constructors, should be able to continue working full-bore.

For nearly a month, the contractor has been working seven days a week, with double shifts most days. When critical repairs had to be made a week ago to repair a leaking cofferdam, construction lasted all night.

Neighbors have complained about the noise and the glare from banks of lights, Holley said.

Except for the cofferdam emergency, construction stops at 9 p. m., with the contractor trying to confine the noisiest work to daylight hours, Holley said.

Monday was an important milestone in the rush to build two supporting piers in the riverbed, Holley said. Pumpers on each bank delivered 340 cubic yards of concrete to complete the construction of the eastern pier wall and lay the foundation for the western support.

The pier foundation starts 28 feet below water and will rise 20 feet above it.

Within a month, the western pier should also be completed, allowing workers to yank the wall of steel that holds back the water that rises and falls with the tides, he said.

Construction ran into difficulties in the early stages, requiring the Fish and Game extensions, Holley said. “We had difficulties excavating some material,” he said. “There is a learning curve to everything.”

Doug Silverwood, American Civil Constructors’ project manager, said he wasn’t allowed to talk about job issues. “It’s going well. We’re still on schedule to finish up on time,” he said.

On days when two shifts of workers are forming rebar for the foundations, the job site has as many as 50 workers, Silverwood said.

Working in a tidal river poses more challenges than building in a steady stream, Silverwood said. With the tide rising and falling as much as 10 feet, “it creates pressures on things,” he said.

The piers and abutments of the First Street bridge will be a lot like those in other bridges, Silverwood said. What will distinguish this span will be the ribbons of glass in the sidewalks and lighting built into obelisks, he said. This span will have “architectural flavor,” he said.