Dix Corp., the longtime Spokane specialty construction company, is working on $21.5 million in improvement projects on two dams on the Snake River in southeastern Washington.


Two of the projects involve upgrades to Ice Harbor Dam, which is located on the Snake roughly 10 miles upstream from Pasco, Wash., and the other is at Lower Granite Dam, which is farther east on the river about 30 miles downstream from Clarkston, Wash. Both dams are operated by the U.S. Army Corps of Engineers.


Scott Tidd, a project manager at Dix, says the largest of the projects is the $13 million construction and installation of a large weir that will modify water flow and allow fishspecifically juvenile salmon and steelheadto travel downstream past Ice Harbor Dam with less difficulty.


The device, called a removal spillway weir, weighs about 1,000 tons and is about 100 feet tall and 60 feet wide. It will be situated on the upstream side of the dam, in front of one of the dams 10 spillway gates.


Dix has hired Thompson Metal Fab Inc., of Vancouver, Wash., to manufacture the weir, which currently is about 70 percent complete, Tidd says. Early next spring, the weir will be barged from Vancouver 230 miles up the Columbia and Snake rivers to Ice Harbor Dam, where Dix will install it. Its scheduled to be in place by the end of next March.


The weir will have two benefits, Tidd says.


Its primary function will be to force water to spill more slowly through one of the dams spillways, which will reduce stress on fish traveling downstream as they go through the spillway. On dams without a weir, when spillways are opened, the water and the fish rush through the dam and shoot out the other side, Tidd says. In such cases, he says, fish oftentimes are stunned and are susceptible to being caught by birds.


Also, with use of the weir, substantially less water is discharged through spillways, and more water is available to run through the dams turbines for power generation, Tidd says.


The Ice Harbor Dam weir is the second such device that Dix has constructed for the Army Corps of Engineers, Tidd says. The company installed the first one in 2001 at Lower Granite Dam. That was an $11.5 million project, he says.


The second current project at Ice Harbor Dam is a $1.5 million crane rebuild, Tidd says.


The 500-ton bridge crane is located in the dams powerhouse. Dix started work on that project earlier this month and is scheduled to complete it next summer.


At Lower Granite Dam, Dix is under way on a $7 million turbine rehabilitation project.


That project involves rebuilding one of the dams six turbines and repairing two others, Tidd says.


The company has completed repairs on one turbine and plans to start work on the others soon. All of those repairs are scheduled to be completed in early 2006, Tidd says.