The Use of Geomorphic Principles in Natural Channel Design: The State 5f“River Restoration Practice in Southern Ontario, Canada
Date of Award
Master of Science
Dr. Peter Ashmore
River restoration and natural channel design attempt to (re)construct channels to emulate the self-sustaining geomorphic and ecologic function of natural watercourses. The practice of river restoration and natural channel design has occurred in Ontario for over two decades, but there has not yet been a review of design approaches and methodologies utilized to achieve the aforementioned function and the overall state of stream design practice. Using the stream design projects in rivers within the jurisdiction of Toronto and Region Conservation Authority and Credit Valley Conservation, two Ontario watershed- based river management agencies, forty-six stream design projects were reviewed and analyzed to assess how and for what extent geomorphic principles are incorporated into the designs. The review and analysis indicated that: 1) project objectives were vague and lacked quantitative baseline data; 2) channel designs were undertaken at the reach scale and did not include watershed conditions; 3) constraints primarily impacted the plan-form of the channel and the degree of natural geomorphic functionality allowed; 4) designs are not influenced by legislative control or specific design methods and requirements, and; 5) that project design was undertaken using a variety of methodologies and approaches (some of which are proprietary), but relied heavily on existing field conditions for design discharges and other parameters. Geomorphic design is done by well- trained and experienced fluvial geomorphologists who are central to ongoing improvement in design methods. There is a strong emphasis on continuing education from junior practitioners working towards their Professional Geoscientist designation, to keeping up with academic research via peer- reviewed journals. Post-project monitoring typically occurs for a maximum of three years. The absence of long-term monitoring hampers the ability of practitioners and scientists to learn from previous designs.
Sampson, Nina Diane, "The Use of Geomorphic Principles in Natural Channel Design: The State 5f“River Restoration Practice in Southern Ontario, Canada" (2011). Digitized Theses. 3591.