Steffen, J., Stringer, J., Daylor, J, Neumann, D. and Zagona, E. (2015). “TAPER—A real-time Decision Support Tool for Balanced Flood Operation of the Arkansas River in Tulsa District.” In Proc 3rd Joint Federal Interagency Conference on Sedimentation and Hydrologic Modeling, April 19–21, Reno, Nevada, USA.


The U.S. Corps of Engineers Tulsa district is responsible for water management of the Arkansas River as it flows through Kansas and Oklahoma including the operation of numerous flood storage reservoirs and five navigation locks. The goal is to minimize flooding throughout the network with the key regulation control location at Van Buren, Arkansas. Upstream of Van Buren are 13 major flood storage reservoirs (7.6 million acre-feet) with 7,200 sq miles of uncontrolled local runoff that are managed to minimize flooding. The system flood evacuation plan calls for releases that evacuate the flood storage as quickly as possible without causing flooding, while still balancing the system storage and tapering down the flow at Van Buren.

During flood operations, Corp staff use a real-time decision support system named TAPER, implemented in RiverWare, which simulates the river and reservoir network, including all of the reservoir operations. The RiverWare model imports observed and forecasted inflows and local runoff and then uses rulebased simulation to model mandatory surcharge releases, allowable flow at various control locations, and the releases to meet the allowable flow in a balanced manner. The regulation discharge at Van Buren is computed based on a seasonally varying guide curves representing the equivalent percent of basin storage utilized. This algorithm allows higher flows during flooding seasons and when the system is full to recover the flood storage space in the upstream projects. The targets also include a smooth tapered recession to bring the system down to normal operations while allowing for scouring and dredging for navigation.

Given this regulation discharge, the RiverWare model computes a set of proposed release to balance the relative reservoir storages while not exceeding the downstream flow targets. Routing is modeled using the step response routing algorithm. Water managers collectively review the proposed releases and river flows and modify releases based on event specific conditions. RiverWare System Control Tables, plots, and output tools provide a friendly user interface focusing on the key variables in the system. As water managers modify releases, the model is re-run to compute downstream flows and reservoir levels. This process repeats until the managers are satisfied. The final release schedule and other reports are sent to dam operators, other federal agencies, local water managers, power authorities and other interested stakeholders.

RiverWare is a river and reservoir modeling tool developed by the University of Colorado Center for Advanced Decision Support for Water and Environmental Systems (CADSWES) with sponsorship of the Tennessee Valley Authority, the Bureau of Reclamation and the U.S. Army Corp of Engineers.