Advanced Gate Operation Strategies in HEC-RAS 5.0

Abstract

The Hydrologic Engineering Center’s River Analysis System (HEC-RAS) is designed for computing water surface profiles and inundation maps, but it is also able to handle flow through gated structures using a variety of equations and techniques. HEC-RAS has a small selection of built-in gate types, representing some of the more common gates that are used for controlling flow at dams and canal structures. Each gate type in HEC-RAS has a set of empirical equations that are used to compute head loss through the structure for a given flow. There are also two operational schemes that can be chosen for gates: Time Series Gate Openings, and Elevation Controlled Gates. While the built-in gate types and operational schemes in HEC-RAS might be appropriate for some of the more common gate structures, it is quite common to have a gate system or other flow control device that simply does not fit within the confines of the built-in techniques in HEC-RAS. In these cases, the user has the option to take advantage of some lesser known techniques both within HEC-RAS and by external applications. This paper will discuss four gate and operation strategies that can be used with HEC-RAS that allow the user to handle any flow control scheme possible. These include Navigation Dams, User Defined Curves, Rules, and the HECRASController API.