By Mr. Preston Chasteen (USACE)October 22, 2019
Record rainfall throughout northern Oklahoma and southern Kansas in May 2019 pushed the Arkansas River to near record heights.
The river at Three Forks less than a half mile upstream of the Port of Muskogee crested at 46.39 feet, approximately 24 feet above normal.
During the flood two barges broke away from their moorings and drifted from the port down the McClellan Kerr Arkansas River Navigation System and slammed into Webbers Falls Lock & Dam 16 on May 23.
Less than a minute after striking the dam, the barges sunk to the base of the structure. The second barge came to rest on top of the first, impeding both the river's flow, and blocking operation of four gates.
"There was never a concern on whether or not this dam would withstand the impact from the barges. These structures were designed to endure a collision of this magnitude," stated Rodney Beard, Tulsa District's Chief of Navigation. "The purpose for this structure is intended to hold pools for navigation and hydropower and are not considered a floods risk structure. A loss of this dam would not be life threatening."
Water levels at this point were so high on the MKARNS that Tulsa District locks 14, 17 and 18 were completely inundated and under water.
Tulsa District engineers determined that because of the pressure of high-volume flows and a lack of proximate capabilities, the wreckage would stay in place under constant monitoring until a salvage crew, which had been contracted by the barge owner, could make its way up the MKARNS from Mississippi. Once onsite, the salvage company, barge owners and the Tulsa District could determine a way forward.
"Our navigation folks as well as folks from our Hydraulic and Hydrological Engineering sections were in constant contact with barge owners, salvage crews and stakeholders," stated Lieutenant Colonel Rick Childers, Deputy District Commander. "We knew this recovery process was going to have a lot of variables, and would be an extremely fluid situation requiring constant communication with all parties involved. Everyone's success in this endeavor would be directly related to how well we communicated."
After traversing high volume flows and navigating around many areas of shoaling caused by the flood water, the salvage crew arrived at Webbers Falls on the morning of August 9.
Salvagers assessed that the Webbers pool would need to be lowered in order to facilitate the removal of the wrecked barges. An exact water level could not be determined so the Tulsa District immediately requested a deviation from Southwestern Division and Headquarters USACE to begin lowering the Webbers pool and maintain lower river elevation until the wreckage could be removed.
As the pool began to drop, the salvagers ran aground two additional barges upstream of the dam to serve as anchors and filled them with water in preparation for the wreckage extraction process.
Once additional anchors were placed, salvage vessels moved into place upstream of the dam and began cutting away pieces of the wreckage with massive shears. To reinforce the hulls of the barges during the lifting process, welders attached supports onto the hull of the barge.
"All the crews worked extremely well together. Everyone had a common goal with a great understanding of the importance of this work to the community and the economy in our area," stated Shane Roe, Major Maintenance Supervisor, MKARNS Navigation Operations.
Over the days of preparation, water levels continued to fall at the rate of about two feet per day, continually easing the water pressure that pressed the twisted metal against the concrete structure.
"The crews worked 7 days a week 12 hours a day. Their hours were made hard by the conditions with the afternoon heat sometimes reaching 130 plus degrees on the barge deck," stated Roe. "All work was in the direct sun in the afternoon and subject to the Oklahoma elements on any given day."
On August 27, the top barge was successfully removed.
The Webbers pool now near elevation 461, approximately 26 feet below normal operating flows, which was almost equivalent to the Robert S. Kerr pool which is immediately downstream of Webbers Falls.
Salvage crews successfully removed the second barge on September 2 and Tulsa District inspectors almost immediately began evaluating the structure and all the affected gates were now able to be closed.
"The great cooperation and communication demonstrated by all involved was instrumental in the successful safe removal and savage of the barges. All crews and personnel worked seamlessly together during this recovery," stated Kenneth Todd, MKARNS Operations Manager.
The Tulsa District began refilling the Webber's pool on September 17, and limited navigation resumed across the entirety of the MKARNS on September 30.
"While this has been an unfortunate sequence of events that have hampered the movement of commodities on this river system for an unprecedented amount of time, the light at the end of the tunnel is shining brightly," stated Beard. "Barge traffic is on the move again in a restricted manner. Sediment or shoaling is still causing some channel restrictions in some areas of the river which is only allowing tows to push 6 barges instead of the normal 12 to 15. Dredging is underway on several areas of the river and the system will soon be back to the pre-flood conditions."
Inspectors detected no major damage to the structure. Minor repairs, which included concrete patching on the icebreakers and replacement of some stop log recesses on one gate were completed.
The flood of 2019 was indeed historic. Oklahoma Educational Television Authority reported that the MKARNS closure cost Oklahoma businesses approximately $2 million dollars per day.