Work on Bull Shoals Dam has began once again except this time around those pesky lights are being made a bit more permanent by being bolted into the concrete. This “work” on the dam is expected to last 9 months.
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Work on the Norfork dam continues as this article from the Baxter Basher reports.
NORFORK — Travel plans are under way for a 130,000-pound bulkhead specially built for maintenance work on Norfork Dam.
Ted Koomen, engineer with Russellville-based Mobley Contractors Inc., said Thursday the bulkhead will be moved by truck to the dam at an undetermined date later this month.
It will be lifted by two 250,000-pound cranes to hang on a giant monorail now built into the dam.
Arkansas Highway 177 will be closed for a time during the bulkhead’s placement.
Boilermaker Doug Simpson of Norfork and assistant Larry Mahan were installing heavy polyvinyl planks on the face of the bulkhead on Thursday.
The planks form casings around large rubber seals on the face of the bulkhead that is expected to fit flush against the lake-side face of the dam, creating a dry environment for work on floodgates and the gears that control them.
The pressure of water displaced by the bulkhead will hold it in place over the work areas, Koomen said.
“We have a number of tests to complete for the (U.S. Army Corps of Engineers) before we stand it up,” Koomen said. A tilt test is expected to show exactly 3-inches of vertical tilt in the structure.
Two construction projects were under way simultaneously Thursday on Norfork Dam.
Builders in scuba gear with hydraulic drills were setting a series of anchor bolts into a 3-foot thickness of concrete to hold 42-inch pipe and intake valves for the White River Minimum Flow System.
When completed, the siphon may draw from Norfork Lake to supplement tailwaters from the dam during times of drought. The siphon is a part of the White River Minimum Flow Project that has been the subject of study by the Corps for decades.
Norfork Dam is a peak-power production facility, using large quantities of water to rush through turbines to create electricity when it’s most needed, such as on hot summer days. At other times, virtually no water flows forth.
That creates an unstable environment for trout, a popular game fish than can flourish in a consistently cold stream but can founder when water slows, pools and warms.
The minimum flow project, initially authorized under a 1999 federal law, would release a continual flow of water from the dams to improve trout habitat.
Both projects are scheduled for completion sometime in March or April this year, barring weather or other natural forces that could delay the $6.6 million project.
The minimum flow system also entails a bore through the dam at the 557.5-foot mean sea level mark.
An expanse of large pipe coming from the port now can be seen descending from the river-side face of the dam.
The project is funded in part by the American Recovery and Reinvestment Act of 2009 in the amount of $3.867 million.
The balance of the funding — $2.790 million — comes from normal federal appropriations to the USACE construction line-item.