The modelling of flows in rivers using computer simulation packages is primarily undertaken to determine where and when floods will occur. The US Army Corps of Engineers Hydrologic Engineering Center River Analysis Software package (HEC-RAS) is one of the most popular river modelling systems currently in use and is available to download and use for free without the restrictions that some competing software packages currently have. In this step-by-step course I will show you how to build a 1-D river model using HEC-RAS. No prior knowledge of river modelling is required. The course is also designed for those with river modelling experience but who have not yet used HEC-RAS. You will build a river network, add structures to your model and run steady and unsteady flow simulations and then examine scenarios such as simulating climate change and creating levees. There is a course manual to accompany the classes which the user can download and work through independently or in conjunction with the video presentations. This workshop will enable you to gain the basic skills associated with 1-D modelling using HEC-RAS and as such will stand you in good stead whether you study river channel processes in academia or work in the river engineering industry.