"Critical Evaluation of How the Rosgen Classification and Associated 'Natural Channel Design' Methods Fail to Integrate and Quantify Fluvial Processes and Channel Responses"

• Published in: Journal of the American Water Resources Association Vol. 44; no. 3; pp. 782 - 792
• Main Authors: Simon, A, Doyle, M, Kondolf, M, Shields, FD Jr, Rhoads, B, McPhillips, M, Rosgen, D L
• Format: Journal Article
• Language: English
• Published: 01-06-2008
• DOI: 10.1111/j.1752-1688.2008.00169.x
• ISSN: 1093-474X

I understand the effort that these authors have expended to meet their stated goals in their abstract to "highlight inconsistencies and identify technical problems of Rosgen's "natural channel design" approach to stream restoration" (p. 1117). It is appropriate to respond formally to the authors' assertions to present the facts of the methodologies rather than rely on the opinions of these authors. The statements made by these authors, in the absence of detailed investigation, point out an obvious problem that if individuals are not trained in the proper use of the classification system and natural channel design (NCD), then inappropriate applications and conclusions can and do occur. As with any tool, it is important to understand its proper use. If the authors had better investigated and become more familiar with the methods in NCD, the majority of their dialog and conclusions would not have necessitated this discussion. The procedures that are referenced to in this discussion counter the inaccuracies made and were all available to these authors for their study prior to the article under discussion. Unfortunately, none of these authors have attended any advanced formal training courses offered or contacted me to inquire about the details of the methods in NCD that have been implemented for over two decades. The unfamiliarity with the NCD method is exemplified in the following statement by the authors: "empirical approaches such as those inherent in "natural channel design"...do not provide cause and effect solutions or means of predicting stable channel dimensions within unstable systems and represent only one possible alternative to evaluating stream types" (p. 1128). The multiple opinions expressed by the authors are not substantiated with facts and are addressed in the following discussion.