A Braun-Jensen crew pours concrete into forms on the front face of the Galloway Diversion Dam on the Weiser River. The
rehabilitation work will ensure that Galloway can serve local farmers for many years to come. (Courtesy of Steve Stuebner)
This story was first featured in the Idaho Soil and Water Commission’s November newsletter, “Conservation the Idaho Way.“
Braun-Jensen Inc. contractors recently completed a $383,000 concrete rehabilitation and resurfacing project on Galloway Diversion Dam on the Weiser River near Weiser.
The project should extend the life of the diversion structure for another 50-100 years.
Braun-Jensen’s crews completed the project in just one month, fulfilling the construction schedule on time, and the project finished on budget, officials said.
The Weiser River Soil Conservation District was the lead sponsor of the project in partnership with the Weiser Irrigation District.
The Weiser River District applied for and received a $124,410 Aging Infrastructure Grant from the Idaho Water Resource Board, and a $150,000 Water Quality Program for Agriculture grant from the Idaho Soil and Water Conservation Commission. Local cost-share funds will make up the difference.
“It looks great! We sure appreciate Braun-Jensen getting the project done on time and on budget,” said Vicki Lukehart, Weiser River SCD administrator.
“It was a good project; it turned out well,” added Rod Panike, chairman of the Weiser River SCD Board of Supervisors. “It was time to get it done. The improvements were definitely needed.”
“The dam was built in 1932, and it was really showing a lot of wear over the years,” added Jay Edwards, manager of the Weiser Irrigation District. “Now it should last another 100 years.”
Galloway Diversion Dam project includes safety upgrades
The project resurfaced the spillway of the 200-foot-wide diversion structure and doubled the width of the top deck to a 4-foot-width for safety purposes.
structure. (Meghan Brooksher/SWC)
Construction work began on the project in late September, and it was completed in late October by Braun-Jensen contractors, a concrete-specialty contractor based in Cambridge, Idaho. Construction crews used jack-hammers to chip away the top 6 inches of the concrete Galloway diversion structure, and then poured 6 inches of fresh concrete on top of the diversion dam. They added more than two feet of width to the top of the diversion structure to create a 4-foot-wide walkway for dam maintenance crews, officials said.
“That’s more of a safety issue,” said Chet Jensen with Braun-Jensen contractors.
On the downstream face of the dam, construction crews added several layers of rebar and fresh concrete to rehabilitate the diversion dam structure.
Concrete for the project was provided by Idaho Materials and Construction. Project design was provided by Braun-Jensen and Bill Lillibridge, an engineer with the Idaho Soil and Water Conservation Commission.
“The ‘bones’ were good – the concrete they chipped into was super-solid,” Lillibridge said of the diversion dam’s concrete structure. “They reinforced the weak spots and added a good, strong, harder concrete finish. It should hold for another 50-100 years.”
Galloway Diversion Dam, located east of Weiser, was built in the 1930s to increase water storage, and it doubled the water rights for farmers and ranchers served by the Weiser Irrigation District to 240 cubic feet per second flow.
Galloway is a critical piece of infrastructure for the Weiser Irrigation District and its shareholders, officials said. The district serves 15,000 acres of irrigated farmland. Farmers in the local area raise a variety of crops including sugar beets, onions, alfalfa hay, seed crops and potatoes as well as livestock.
Galloway Diversion Dam provides multiple economic values to irrigators, municipal water for the City of Weiser (population 5,812), recreation and fishing benefits.
“Weiser is a big agricultural area,” Edwards said. “It’s a multi-million-dollar industry in our area, and the Galloway Diversion Dam is a crucial part of our irrigation infrastructure.
“We thought it’d be a wonderful idea to work with the Weiser River District to apply for the grants from the Idaho Water Resource Board and the Idaho Soil and Water Conservation Commission to reduce our costs. Those grants really made the project possible. It’s highly unlikely we could have gotten it done without them.”
Protecting water quality on the Weiser River
The Weiser River SCD was organized in December 1941. It is one of 50 conservation districts in state of Idaho. It serves farmers and ranchers in Washington County.
The Weiser River District works on a wide variety of conservation projects to improve water quality on the Weiser River and reduce sediment, phosphorus and nitrate runoff from local farms.
In 2014, the Weiser Irrigation District installed automated headgates on the canals carrying water from Galloway to local farms. That improvement extended the irrigation season by an extra 30 days in the fall by providing a more accurate accounting of water consumption from the Weiser River and reducing losses in the irrigation delivery and return drain system.
“We’ve got the water management and water measurement down to a gnat’s eyebrow,” Edwards said. “Everyone wants to make sure they get their fair share.”
Pre-construction, the dam spillway was eroding to the point where large rocks were protruding out of the concrete with large sinkholes where the concrete had already crumbled. The concrete and foundation were eroding away on the backside of the diversion dam, and it would be only a matter of time before there would be a break in the dam, officials said.
“The dam was nearly 100 years old, it’s been eroding exponentially every year,” the grant application said. “It is imperative that repair work be completed on this project to keep Galloway dam functional for another 100 years.”
“That dam needed to be brought up to today’s standards,” Panike said. “It really turned out well.”
Next spring, the Weiser River SCD will host an educational tour with the Weiser Irrigation District and local stakeholders. Information about the project also has been shared at the Washington County Fair, Division III meeting with other conservation districts, and the Washington County Commissioners.
(photo by Meghan Brooksher/SWC)