The U.S. Army Corps of Engineers Corps (USACE) Hydrologic Engineering Center (HEC) is responsible for developing generalized engineering software to support the Corps’ water resources management mission. Most of these tools are also freely available to the public through the HEC website.
Reservoir operation for flood control is the Corps’ primary function. Other important operating objectives considered include water supply, hydropower generation, and releases for environmental flows. HEC’s principal software for modeling reservoir operations is HEC-ResSim. RMA has served under HEC contract as the primary software developer for the HEC-ResSim computational engine and graphical user interface since HEC-ResSim development began in 1998.
HEC-ResSim represents a river-reservoir system as a georeferenced network of reservoir, routing reach, stream junction, and diversion elements. The model includes data that represents both the physical and operational aspects of the system. Physical data includes reservoir elevation-capacity tables, complex outlet works, power-plant specifications, and river-reach routing parameters. Operational data is represented as rule stacks, which allow users to identify and prioritize multiple reservoir operation rules. The model supports both local rules for at-site operations and system operation rules for downstream control, system hydropower generation, and tandem/parallel system storage balancing. Advanced simulation modes include Monte Carlo analysis, ensemble simulation, and firm yield analysis.
HEC-ResSim has been used in studies of large and small systems throughout the United States and around the world. Important applications include:
- Columbia River system in the Pacific Northwest
- Alabama, Coosa, Tallapoosa and Apalachicola, Chattahoochee, Flint river systems in Alabama, Georgia, and Florida
- Savannah River system in Georgia
- Sacramento and San Joaquin River system in California
- Tigris-Euphrates river system in Turkey, Syria, and Iraq
HEC-ResSim is a desktop Java application that makes extensive use of large Java-based libraries developed by RMA for HEC. The libraries provide the application framework, data management, database access, user interface components, georeferenced mapping, and engineering calculations.
Results and benefits
HEC-ResSim is the primary tool for reservoir system simulation in support of the Corps’ water management mission. RMA has worked continually with the USACE HEC over many years to develop and refine the capabilities of HEC-ResSim in response to Corps districts’ operational experience.