Natural Channel Design for River Restoration

Abstract

AbstractThe Natural Channel Design (NCD) approach to river restoration aims to establish a self‐regulating, functioning river system associated with physical, ecological, and chemical components by emulating the natural stable form within the constraints imposed by the larger landscape conditions. The NCD method has evolved over five decades to restore impaired rivers using principles from fluvial geomorphology and ecology to meet clearly defined restoration goals. NCD incorporates analog, empirical, and analytical methods through 10 sequential phases that serve as a designframeworkto guide users through the minimum requirements and specific procedures to successfully implement a restoration design. An appropriate reference reach must be selected to direct the natural channel design and determine the physical and ecological departure of the impaired reach from the stable and functioning reference condition. Designing a multistage river system is also an integral part of NCD based on the appropriate stream type for the fluvial landscape. The NCD approach has successfully offset many of the adverse impacts from land use activities and traditional river works by implementing sustainable designs that are intended to work in harmony with river systems.