Commission to open bids for sediment removal

WORLAND — In advance of a county project to remove a sediment bar from the Big Horn River, the Washakie County Commission will open bids today at 10 a.m., before awarding the project.

The estimated 1.3 acres of sand and sediment in question has been the catalyst for ice jams and flooding along the river as it runs through Worland, growing steadily over the last three years. An initial survey of the mass estimated over 18,700 cubic yards of material had built up, at a depth of five feet.

Previously, the commission contacted the Wyoming Bureau of Reclamation (BOR), to request that canal volume be lowered during the time of the project, to ensure safety and ease of work for the contractor removing the material.

Using 18,700 cubic yards equation, the county estimated the cost of removal just under $60,000, not counting the use of city and county trucks to haul away the material.

County Planner David Anderson recommended a wider timeframe for the project, originally advertised to bidders to end no later than Oct. 6.

Currently, the Big Horn River is running 1,100 cubic-feet-per-second (cfs) due to discharge from the canal systems south of Worland, fed from Boysen Reservoir, controlled by the BOR. According to the commission, the optimal flow rate would be around 600 cfs during the removal of the sediment, both for ease of work and for safety reasons. The reduction in rate would amount to a 1.5 to 2-foot drop in river depth.

When contacted, an engineer for the BOR stated that the agency would be willing to coordinate efforts to regulate the flow during the project, with the approval of the Wyoming Game and Fish Department, as the flow rate would also affect fishing in the area.

In February, the Senate Committee on Environment and Public Works (EPW), heard from Wolf at a committee oversight hearing on “Flood Control Infrastructure: Safety Questions Raised by Current Events” held in Washington, DC.

Reading from a prepared statement, Wolf outlined recent flooding issues, due to a sedimentary island in the Big Horn River that causes frequent ice jams, stating in part that “We are still evaluating the total costs to our communities in damage and clean-up costs, but estimates of state and local costs will likely exceed $150,000.”

At that time Wolf asked the committee to consider using the Army Corp of Engineers to help Worland remove the island, referencing a section of the Water Infrastructure Improvements Act for the Nation, dealing specifically with flooding caused by ice jams.

At a public meeting earlier this year, Tom Johnson with the Army Corps of Engineers noted that Section 404 of the Clean Water Act requires a permit to remove material from the river, although the city and county would not need a permit to redistribute the sediment blocking the river, or transfer it to build berms.

Johnson recommended that as long as the bank was not altered, the county could dig out the sediment and transfer it to trucks, for further county use. Any sediment that fell in the process was considered spillage and was admissible without a permit. In all, the Army Corps would not need to be involved with the project to remove the sediment.