Engineering Design Standards and Liability for Stream Channel Restoration

Abstract

At the annual meeting of the Environmental and Water Resources Institute EWRI River Restoration Committee at the World Water and Environmental Resources Congress in May of 2005, a lively discussion was held on engineering liability issues associated with river restoration projects. Why engineering liability issues? Because by sealing river restoration designs, engineers assume professional liability for those designs. The course of the liability discussion led the authors to conclude that there is a need for objective, performance-based guidelines or a manual of practice for river and stream restoration design as well as improved channel design standards. This article reviews the state of practice of restoration design and suggests a basis for design standards to improve project results and manage risk. The River Restoration Committee hopes to see a broader professional acceptance of multiple scientific design approaches for river restoration projects, a distinction between engineering and nonengineering practices, and quantifiable project goals to more easily evaluate success or failure. For example, the Committee would like to see regulatory agencies adopt performance-based criteria for river restoration designs to meet specific objectives rather than guidelines or rules that constrain engineers to use a prescribed design approach. By gearing designs to satisfy specified, measurable criteria, engineers will be able to select the most appropriate design methods for a given project across a wide variety of boundary conditions and system processes. Tailoring a solution to satisfy quantifiable goals for given stream and watershed conditions over the lifespan of the design makes more sense than trying to fit a prescribed design approach to all types of projects over a wide range of project and watershed scales.