POULSBO – A detour isn’t in the cards for Poulsbo commuters this summer as culverts on State Route 305 are replaced, but that doesn’t mean there won’t be traffic delays.

The original culvert replacement plan called for an estimated 10-minute traffic detour, but a new plan will keep traffic on SR-305 and call for one lane to be closed, according to City Engineer Andrzej Kasiniak.

“The cost of the project dropped and one of the reasons why is the detour was costly to keep open for so long,” Kasiniak said. The culvert work will begin in July.

The culverts are at Bjorgen and Lemolo Creeks, which are on both sides of Noll Road.

Jerry Moore, an engineer with the state Department of Transportation, said the roads set aside for the detour — Lincoln Drive, Windme Road and Totten Road — would need additional maintenance to sustain the amount of traffic the detour would have caused.

The detour route was also removed because the department of transportation changed project’s scope. The plan originally involved digging trenches in the road to lay pipe, creating the need for a detour.

“I’ve got great news for you, and that is we’re not going to screw up the traffic in town,” Moore said during a Poulsbo City Council meeting Wednesday night.

Trenchless technology offers two methods of construction: pipe jacking and pipe ramming. Both are performed on the side of the road tunneling under the road instead of open trenches. It will be up to the contractor to decide which method of trenchless technology to use. The names of the methods might sound similar but they are quite different, Moore said.

“The method (of jacking) is basically using brute force to push the pipe through the fill,” Moore said.

This method would require building a structure for the equipment to push against.

“Normally jacking operations are often done down, below deep in a hole when you’re pushing against earth,” Moore said. “The best way to describe (ramming) is a sideways pile driver. It doesn’t have to have that massive structure to push against. It brings a hammer and it pounds it through.”

While these new methods eliminate the need for a detour, they do tend to have more problems.

What lies beneath the earth can often be a surprise, Kasiniak said.

“Often you’ll hit some kind of anomaly in the ground like a big boulder,” Moore said.

Several options are available to deal with any obstructions in the pipe path, which should keep the overall time of construction down.

“We are just about ready to go out to bid,” Moore said.

The transportation department will take more soil samples in the coming weeks to determine more in-depth characteristics of the construction area.