By Brannen ParrishOctober 24, 2019
At approximately 275,000 cubic feet per second, the flood of May 2019, resulted in the highest releases from Keystone Dam into the Arkansas River since 1986.
Though significantly smaller than the approximately 305,000 cfs release in 1986, potential impacts to downstream flood risk reduction structures caused enough concern that local officials requested the Tulsa District, U.S. Army Corps of Engineer's expertise.
When flows on the Arkansas River below Keystone Dam reach approximately 150,000 cfs the entire length of the Tulsa West Tulsa Levee System is loaded. The system stretches approximately 20 miles from Sand Springs, Oklahoma to Tulsa and reduces flood risk for approximately 10,000 people who live or work behind the structure.
As flows on the Arkansas River increased, Tulsa County Drainage District 12, which owns and is responsible for maintenance of the levee, requested assistance from the Corps of Engineers. The Corps of Engineers responded by providing consultation and technical advice on methods to protect the structure.
"For this event, we were requested by the Levee District 12 through Emergency Management channels but the Tulsa District, U.S. Army Corps of Engineers provides continual support and technical assistance to the Levee Sponsors that are in the Tulsa District Levee Safety program," said David Sconyers, the Chief of Infrastructure, Tulsa District.
The Tulsa District provided engineers, including geotechnical engineers, and other technical specialists who made assessments in the field during the flood.
These Corps professionals identified areas of concerns and applied appropriate flood fight techniques to mitigate impacts of a loaded levee flooding during the event.
The engineers also provided training to members of the National Guard who were called up by Oklahoma Governor. Corps experts trained the guardsmen to identify potential problems like sand boils, embankment slides and seepage.
"The National Guard was very beneficial to maintaining the integrity of the levee, by providing personnel that could patrol and monitor areas for possible progression of issues," said Sconyers. "The Guard would notify the levee sponsor and USACE of any issues that they noted, so that we could make an assessment of those areas. Finally, they provided personnel to assist in flood fight efforts, moving and placing sandbags, in a very timely and proficient manner to address areas of major concern."
Other Tulsa District offices provided support for the flood fight including, Emergency Management, Logistics, Contracting and Hydraulics and Hydrology.
Dr. David Williams, Chief of Hydrology and Hydaulics Engineering Section of the Tulsa District, was stationed in the City of Tulsa's Emergency Operations Center during the flood to explain Corps operations to local officials.
"The coordination between USACE and local officials, including the City of Tulsa and Tulsa Area Emergency Management Agency, was essential during the recent flood," said Williams. "By communicating and explaining the release plan with as much advance notice as possible, the City of Tulsa and local agencies were able to make preparations to infrastructure and to provide warning to citizens who live and work within the affected areas."
The Levee Safety Program for the Tulsa District consists of annual and periodic (five year) inspections that include risk assessments. The inspections identify deficiencies and the Corps provides guidance on remedial measures, so that the levee and levee district personnel are prepared for a potential flood event.
"The relationship between the Corps of Engineers and the levee sponsor is important for an effective levee safety program," said Jordan Holmes, Levee Safety Program Manager, Tulsa District. "We work closely with levee sponsors so that deficiencies are acknowledged and addressed, and we listen to the sponsors' concerns."
Levees inspected by the Corps of Engineers are included in the National Levee Database which is available to the public at https://levees.sec.usace.army.mil/.
The database provides information to the public about the status of levees to improve public awareness of risks associated with residing behind levees.
"After the water recedes, Tulsa District personnel will continue to work with the levee sponsors to identify any additional deficiencies and assist in the mitigation of these issues within the bounds of our authority," said Sconyers.
The Tulsa West Tulsa Levee System was constructed by the Tulsa District and turned over to Tulsa County Drainage District 12 for operations and maintenance in the 1940s. The structure provides a level of risk reduction to portions of Tulsa County along the Arkansas River.
The Flood Control Acts promulgated by Congress between 1936 and 1985 resulted in nearly a half century of unprecedented infrastructure spending and construction for flood risk reduction structures.
By boldly declaring "flood control" to be an "interest of the Federal Government" through the Flood Control Act of 1936, Congress opened the gates to studies, authorizations and appropriations designed to stymie the flow of uncontrolled waters that ravaged the nation in the first thirty years of the 20th Century.