Scaling of Reference Reach for Desired Bankfull Discharge

Abstract

The reference reach method is commonly used for natural stream design. In the reference reach approach, a stable reach is selected to serve as the design template for a design reach. The planform and profile of this reference reach must be scaled to fit the design site. Currently, the leading method for scaling uses a simple ratio of cross-sectional areas. This paper presents a simple method that employs hydraulic scaling to size the design reach to accommodate the desired bankfull flow. The method introduced in this paper is easy to use, does not require additional survey data, and should lead to more robust channel design.