Short Name: HEC-RTS
Long Name: Hydrologic Engineering Center Real Time Simulation
Platform Type: Desktop application
Usage: It is a comprehensive data acquisition and hydrologic modeling system for short-term decision support of water control operations in real time. The forecasting framework includes integration of HEC-MetVue, HEC-HMS, HEC-ResSim, HEC-RAS, and HEC-FIA.
Background: HEC-RTS provides support for operational decision making by forecast simulation modeling using any combination of the following models. Meteorological data processing with HEC-MetVue. Rainfall-runoff modeling with HEC-HMS based on gaged or radar-based precipitation, Quantitative Precipitation Forecasts (QPF) and other future precipitation scenarios provides forecasts of uncontrolled flows into and downstream of reservoirs. Simulation of reservoir operations with HEC-ResSim provides operational decision information for the engineer. The river hydraulics program HEC-RAS computes river stages and water surface profiles for these scenarios. An inundation boundary and depth map of water in the flood plain can be calculated from the HEC-RAS results using RAS Mapper. The impacts of different flow alternatives are computed by HEC-FIA. The user-configurable sequence of modeling software allows modelers to evaluate operational decisions for reservoirs and other control structures, and view and compare hydraulic and economic impacts for various “what if?” scenarios. The first version was released in 2017. The current version was released in 2025.
Channel routing:
Reservoir operation:
Shortwave radiation:
Longwave radiation:
Precipitation:
Evapotranspiration:
Snowmelt:
Infiltration:
Surface runoff:
Baseflow:
Input Data: Precipitation at a minimum. Air temperature for snowmelt. Some methods may require atmospheric pressure, windspeed, and relative humidity or dew point temperature. Physical and operational characteristics of dam and reservoir: storage, elevation, area, volume, evaporation rate, leakage rate, operation location, index level, outlet capacity, control point data.
Time-series, gridded (radar and output from numerical weather models), and ensemble meteorological data can be ingested, displayed and used within hydrologic simulation.
Input Format: HEC-DSS file format, programming API available. For maps: Shapefile, DEM, ASCII TIN, and GeoTIFF raster images.
Data Latency: The modeler can customize how frequently new meteorological and land surface observations are ingested.
Model Output Time-Series: HEC-MetVue outputs times series of gridded data as inputs for HEC-HMS and HEC-RAS. Additionally, all models integrated into the HEC-RTS platform can save and exchange non-gridded time-series data in the forecast results file. For example, HEC-HMS will save flow time-series, HEC-ResSim will use the HEC-HMS results and perform reservoir routing. HEC-RAS will use both the HEC-HMS and HEC-ResSim results to compute river stages and floodplain inundation.
Platform Output Time-series: Flow, stage, flood inundation is available at all elements. Specified or simulated atmospheric variables. Additional types of data are available for canopy, surface runoff, infiltration, baseflow, and reservoir pool state variables.
Reservoir storage, elevation, controlled release and uncontrolled spill parameters; Regulated, unregulated and cumulative local flow; Regulated, unregulated and cumulative local stages;
Hydropower: generation efficiency, power head, hydraulic losses, energy generated, plant factor; Gate opening.
Dynamic, raster and shapefile output for: Depth, WSE, Velocity, Courant, Percent Time Inundated, Energy, Arrival Time, Duration, Shear Stress, Depth*V, excess depth, infiltration depth, Eddy viscosity, governing terms of equations, and much more.
Data Download Format: HEC-DSS file format, programming API available
Analysis: Types of analysis supported include:
- Data extraction, visualization, and editing
- Ensemble analysis
- Hydrologic model optimization and calibration
- Model performance metrics and results visualization
- Customization of detailed summary reports
Additional Models Availability: Other models can be integrated following published documentation for a plugin approach.
Riverware for reservoir simulation:
Installation Resources: Local
Installation: Easy – Portable installation package
Access: Not applicable
Platform Hosting: Not applicable
User Education: BSc
Degree of Difficulty: 3
GIS Expertise: Not required, but GIS knowledge will improve all models integrated into a project
IT Expertise: Not required
Hardware Requirements: PC with multi-core processor
Operating System: Windows
Supported Browser: Chrome and others
Language of Core Code: Primarily Java with some Fortran components for I/O, scripting in Jython dialect of Python that runs in the Java Virtual Machine, .Net
Open Source: No
Latest Update and Version: October 2025 (Version 3.5.0)
Next Update and Version: Summer/Fall 2026 (Version 3.6)
Active Development Community: Yes
Model Integration: HEC-MetVue, HEC-HMS, HEC-ResSim, HEC-RAS, and HEC-FIA
Download URL: https://www.hec.usace.army.mil/software/hec-rts/downloads.aspx
Free to Download and Use: Yes, no registration required
Language of Software Interface: English
Online Support URL: https://www.hec.usace.army.mil/software/support_policy.aspx
Training Material URL (including example data sets): https://www.hec.usace.army.mil/confluence/cwmsdocs/ctg
Language of Trainings: English
Guidance Material URL (including case studies and benchmarking of performance/speed): https://www.hec.usace.army.mil/confluence/cwmsdocs
Language of Guidance: English
References: https://www.ufrgs.br/gpden/wordpress/wp-content/uploads/2022/12/Fagundes-et-al-2022-Book-chapter-HEC-RTS.pdf
Owner, Developer:
US Army Corps of Engineers
https://www.hec.usace.army.mil
Mailing Address:
Department of The Army
Corps of Engineers
Institute for Water Resources
Hydrologic Engineering Center
609 Second Street
Davis, CA 95616-4687
HEC Phone: +1 530.756.1104
HEC Fax: +1 530.756.8250