Lowering the navigation pool upstream from Webbers Falls Lock & Dam 16 became a little tricky due to concerns of local businesses and a municipality that rely on the water resource.
District 1 Commissioner Ken Doke said pumps used to draw water from the McClellan-Kerr Arkansas River Navigation System, and a tributary could be rendered useless because they are positioned above projected water levels. The U.S. Army Corps of Engineers announced this past week plans to lower the pool to 480 feet at the downstream dam and possibly lower.
“Fort Gibson is taking preemptive measures in case for whatever reason the water level falls below their intake,” Doke said Monday during the commissioners’ regular meeting. “They have a number of plans they are looking at — so if it becomes an issue they will have two or three contingency plans they will be ready to put in place to address water issues in Fort Gibson.”
Justin Cook, an engineer of Cook Consulting who is working with the town, said one alternative is getting water from the city of Muskogee. The city of Muskogee has a raw water line that stretches from the Fort Gibson Dam to its water treatment plant at the Port of Muskogee.
Cook said that remained the primary option on Monday, but he also is studying hydrographs provided by the Corps and assessing other options. Those hydrographs project water levels at the location of Fort Gibson’s water intake in relation to those at Webbers Falls Lock & Dam 16.
Public Information Officer Preston Chasteen at the Corps’ headquarters in Tulsa said the navigation channel was raised on Aug. 13 to about 491 feet, allowing commercial barge traffic to vacate the pool, before beginning to lower it. The pool was being lowered to accommodate efforts to salvage two barges swept away by floodwaters in May from the Port of Muskogee.
The runaway barges sank immediately after striking the Webbers Falls Dam, where they have been “pinned tightly against” the structure. Chasteen said salvage crews will assess the situation once water levels are lower, and salvage operations and dam repairs will resume as conditions allow.
Bill Smiley, the Corps’ Tulsa District chief of emergency management, said the federal agency has provided technical assistance to the town of Fort Gibson, which pumps its municipal water supply from the Grand (Neosho) River. Smiley said the Corps lacks the “authority to provide direct assistance for this type of event.”
Technical assistance, Smiley said, included projections for water levels where the town’s intake line is located and an offering of ideas about potential backup systems. He said it is the Corps’ policy to let municipalities make the decision about what options will be used to mitigate any risks.
“Our real job is to provide additional options that communities may not be thinking about in terms of engineering regarding water because that is our forte,” Smiley said. “We also do coordination on a federal and state level with our emergency management partners to provide as much support to our community partners in charge of the event — try to leverage our federal resources to help locals.”
Doke said in addition to Fort Gibson’s municipal water supply, some Muskogee County farmers who pump water from the navigation pool to irrigate crops may have to consider contingency alternatives.
“It is going to be a very fluid situation — you just don’t know what is going to happen,” Doke said, noting that any contingency plans need to be good potentially for several weeks. “It’s going to be a strange year, because at one point we were looking at some of the highest water levels we had ever seen and now we could see some of the lowest.”