HEC-WAT Framework - Basic Conceptual Diagram

The HEC-WAT software install package includes plugins for the following HEC software applications:

Hydrologic – HEC-HMS

HEC-HMS (http://www.hec.usace.army.mil/software/hec-hms/) is a standalone software application that is designed to simulate the precipitation-runoff processes of dendritic watershed systems. The software is designed to be applicable in a wide range of geographic areas and is a generalized hydrologic modeling system capable of representing many different watersheds to simulate either a single flood event or a continuous simulation that spans a couple of weeks or multiple decades. A model of the watershed is constructed by selected modeling methods for different components of the hydrologic cycle defining meteorologic boundary conditions. HEC-HMS in the HEC-WAT compute sequence is a hydrologic precipitation rainfall-runoff model that generally provides simulated flow at multiple locations within a watershed.

Reservoirs – HEC-ResSim

HEC-ResSim (http://www.hec.usace.army.mil/software/hec-ressim/) is a standalone software application that is used to model reservoir operations at one or more reservoirs whose rule-based operations are defined by a variety of operational goals and constraints. The software simulates reservoir operations for flood management, low flow augmentation and water supply for planning studies, detailed reservoir regulation plan investigations, and real-time decision support. HEC-ResSim in the HEC-WAT compute sequence is a reservoir simulation model that provides regulated flow hydrographs. Results from both HEC-HMS and HEC-ResSim can be used by the hydraulics model.

Hydraulics – HEC-RAS

HEC-RAS (http://www.hec.usace.army.mil/software/hec-ras/) is a standalone software application that allows the user to perform one- dimensional steady and unsteady flow and two-dimensional unsteady flow simulations. HEC-RAS also includes sediment transport/mobile bed computations and water temperature modeling. HEC-RAS contains four one-dimensional river analysis components for: (1) steady flow water surface profile computations; (2) unsteady flow simulation; (3) movable boundary sediment transport computations; and (4) water quality analysis. The HEC-RAS Mapper tool that is available from the HEC-RAS interface, calculates inundation boundary and water depth maps. HEC-RAS in the HEC-WAT compute sequence is a river hydraulic model that computes the river stages, water surface profiles, and levee breach information that is used to compute consequences by HEC-FIA.

Consequences – HEC-FIA

HEC-FIA (http://www.hec.usace.army.mil/software/hec-fia/) is a standalone software application that evaluates consequences using either continuously observed or simulated stage hydrographs (hydrograph-based) or depth grids (GIS-based). For a specified analysis, the software evaluates urban and agricultural flood damage, area inundated, number of structures inundated, and consequences. Consequences include economic and life loss. HEC-FIA also provides information to flood managers and emergency managers for emergency response activities.