Hydraulic modelling

Herrington Consulting has extensive experience in constructing 1D numerical river models and pipe networks for use in Flood Risk Assessments and Studies using a wide range of 1D numerical modelling software. From basic spreadsheet models to detailed dynamically linked 1D/2D TUFLOW models, Herrington Consulting has the ability to apply the most appropriate model to suit all types of sites and budgets.

This wide range of software also enables us to accurately model watercourses of varying sizes, for an array of extreme scenarios. Consequently, we can simulate the propagation of floodwater flowing out of the river and across the flood plain, thus quantifying flood depths across the study area.

HEC-RAS (Hydraulic Engineering Center - River Analysis System) is a one-dimensional hydraulic analysis model for steady and unsteady flow water surface profile computations and it is used by Herrington Consulting to model small channel watercourses. HEC-RAS is designed to perform one-dimensional hydraulic calculations for a full network of natural and constructed channels.

Although HEC-RAS is an excellent tool, and still frequently used by our modellers, it does have some limitations. Depending on the site characteristics it may be more appropriate to utilise a more dynamic 1D model which can be linked to a more detailed hydrodynamic model if required. For such projects Herrington Consulting applies the ESTRY 1D numerical model.

The dynamic linking capability between 1D model domains and 2D model domains is a major strength of the TUFLOW software used by Herrington Consulting. With the adaptation of TUFLOW to floodplain modelling, more flexible and complex linking has been developed. The advanced linking functions have been extensively applied to a wide range of models varying from major river systems to fine-scale urban flood models to coastal storm tide inundation. This enables sites to be modelled in detail and depths to be accurately quantified, as well as enabling flood relief schemes to be tested before construction.