A significant part of the road construction on U.S. Highway 95 on the Winchester hill is intended to allow fish passage in Lapwai Creek that follows the roadway.
Curtis Arnzen, Idaho Transportation Department project manager for the ongoing work, said the design involves replacing nine large culvert that are 11 feet in diameter to allow easier access for spawning fish in the creek.
“The pipes that were in place before the project, they were fish blockages,” Arnzen said Thursday. “So we worked closely with the Nez Perce tribal fisheries to come up with a good fish passage design. There’s a lot of steelhead population in the creek — more significant than you realize. They go up to Lapwai Creek and the juveniles are still in Lapwai Creek. One of the things that was helpful is that the tribe was really on board with the project, and they really saw the benefits of having the fish passage along with it.”
The Winchester hill activity is the second of a two-phase design between mileposts 279 and 282 near the northern exit to Winchester. The first phase, which extended the passing lane near Culdesac, was completed in 2016 and cost $27 million. The current work started in the spring and will continue this fall until the ground is too frozen to allow for digging or blasting, said Reed Hollinshead, a spokesman for the department. It will resume in the spring and is expected to be completed by October 2020.
A third phase is expected to begin in 2023.
During construction, one 11-foot-wide lane has been opened for traffic in each direction. The road is being closed periodically between 6 and 7 p.m. to allow for blasting.
Arnzen said large shipping containers have been placed alongside the road as buffers against rocks and boulders that cascade down the cliff side during the blasting.
“When the contractor blasts, they set the containers up in case a loose rock gets free,” Arnzen said. “The intent is to keep loose rock out of the creek.”
So far workers have removed about 200,000 cubic yards of rock during the excavation. For comparison, Arnzen said a normal truckload carries about 12-15 cubic yards of loose rock.
Much of the blasted rock is being reused as filler around the nine culverts.
The contractors, M.A. DeAtley Construction Inc., of Lewiston “are doing a good job of reusing (the rock), and they’re also crushing it for the new passing lane,” Arnzen said. “A lot of the rock left over is good quality, and it might be able to be used on future projects or aggregate.”
The plan is to pave the short stretch of roadway where the work is going on before construction stops for the winter, Arnzen said.
“We won’t pave the full passing lane, but we will repair the existing pavement so that it travels better for the public,” he said. “That’s the intent, and we’re really pushing hard to make that happen. Barring unforeseen instances, that’s what we plan on.”
The overall project, he said, has gone smoothly with few problems. A crane tipped over in June and it took a few days to remedy that situation, but otherwise the work has had few hiccups.
“It’s gone very smoothly,” Arnzen said. “I’m pleased with how it’s gone so far.”
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