EVALUATION OF 'NATURAL' CHANNEL DESIGN APPLICATIONS IN SOUTHWESTERN ONTARIO A Thesis Presented to The Faculty of Graduate Studies of The University of Guelph by RYAN NESS In partial fulfillment of requirements for the degree of Master of Science August, 2001 ORyan Ness, 2001 National Library Bibliothèque nationale 1*1 of du Canada Acquisitions and Acquisitions et Bibliographie Services services bibliographiques 395 Wellington Street 395. me Wellington Ottawa ON K1A ON4 Ottawa ON K1A ON4 Canada Canada Yovr fi@ Votre rBfemce Our fil8 Notre rëfdrence The author has granted a non- L'auteur a accordé une licence non exctusive licence diowing the exclusive permettant a la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or sell reproduire, prêter, distribuer ou copies of this thesis in microfom, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/fïlm, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protege cette thèse. thesis nor substantid extracts fiom it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. ABSTRACT EVALUATION OF 'NATURAL' CHANNEL DESIGN APPLICATIONS IN SOUTHWESTERN ONTARIO Xyan Ness Advisor: University of Guelph, 2001 Dr. D. Joy .Natural7 channel design is a practice increasingly used in restoration projects to construct watercourse channels that emulate the physical form and function of natural fluvial systems. However, little is known regarding the success of 'natural' channei design in attaining the stability that characterizes natural systems. A research study was conducted to evaluate the long-term performance of 'natural' channel design applications in five strearns in Southwestern Ontario. The existing condition of the study channels was characterized through qualitative obse~ation,topogaphic surveys, bed material sampling, and numericd modelling. The results were compared with baseline data to assess channel change since construction. Findings demonstrate that the study channels had maintained a relatively stable form over a period of 4 to 7 years. However, natural physical function was not achieved at any of the study sites because the boundary matenal used to form the channels was too large to permit channel adjustment. There was also that evidence that inconsistencies and errors in design methods may have resulted in channel designs that were incompatible with local conditions. ACKNOWEDGEMENTS 1 would like to thank to my advisor, Dr. Douglas Joy, for the opportunity to pursue research in this area and for his guidance and advice throughout this project. 1 would dso like to acknowledpe Dr. Hugh Whiteley and Dr. Ray Kostaschuk for their involvement in my advisory cornmittee and for their timely and thorough review of this thesis. Thanks also to Matt Walker for his outstanding work as a field assistant. 1 would especially like to thank my parents for their unwavering support of my post-secondary and post-gaduate education. Thanks also to my friends and fellow graduate students who have made the past two years interesting and enjoyable. Sara, thanks for helping me get through the tough times and for showing me how to have fun no rnatter what. This research was funded by a National Science and Engineering Résearch Council Post-Graduate Scholarship. Information provided by the Grand River Conservation Authority, City of Mississauga, City of Cambridge, City of Waterloo, the City of Kitchener, Hdngton and Hoyle Ltd., and Cumming-Cockburn Ltd., was invaluable in completing this study. TABLE OF CONTENTS ACKNO WLEDGEMENTS ................................................................................................. i ... LIST OF TABLES ........................................................................................................... viri LIST OF FIGURES ............................................................................................................. x 1. 0 INTRODUCTION ....................................................................................................... I 2.0 BACKGROUND AND LITERATURE REVIEW ..................................................... 4 2.1 The fluvial System.................................................................................................. 5 2.2 Channel Process and Response .............................................................................. 6 2.3 The Equilibrium Concept ...................................................................................... II 2.4 The Channel-Forming Discharge .......................... ..... ..................................... 12 2.5 Channel Geometry of Natural Rivers and Strearns ......................................... 14 2.5.1 Cross-Sectional Form .............................. .... ............................................... 15 2.5.2 Bed Configuration ......................................................................................... 17 2.5.3 Plan Forrn .................................................................................................. .. 20 2.5.4 Channel Slope ............................................................................................. 22 2.5.5 Geometry of Southem Ontario Rivers and Streams ..................................... 23 2.6 Human-Induced Channel Change ................................................................... 24 2.7 'Natural' Channel Design .................. ..... ....................................................... 27 2.7.1 The Rosgen Classification System .............................................................. 32 2.7.2 Results of Natural Channel Design ............................................................... 34 2.8 Modelling in the River Environment ................................................................... 36 .. II 3 .0 PURPOSE AND OBJECTlVES ................... ,.. ...... ............................................ 3 9 4.0 METHODOLOGY.................................................................................................... 40 4.1 Site SeIection ......................................................................................................... 40 4.2 Site Characterization ............................................................................................. 42 4.2.1 Preliminary Inspection ................... .. ........................................................... 42 4.2.2 Topographie Survey ................................................................. ... ............. -43 4.2.3 Bed Material Sarnpling .................................................................................. 45 4.3 Sumey Data Analysis ........................ ..., ........................................................... 46 4.4 Discharge Data ...................................................................................................... 47 4.5 Numerical Modelling .......................................................... ..... .................... 48 4.5.1 Modelling Software Selection .......................... .., .......................................... 48 4.5.2 Mode1 Description .................................................................................. 50 4.5.3 Cross-section Data......................................................................................... 51 4.5.4 Roughness Parameters ................................................................................... 52 . 4.5.5 Boundary Conditions .................... ,.,, .............................................................. 53 3.6 S tabili ty Analysis .................................................................................................. 54 5.0 RESULTS .................................................................................................................. 56 5.1 Laurel Creek .......................................................................................................... 56 5.1.1 Description of Design .................................................................................... 57 5.1.2 Preliminary Inspection .................................... .... .......................................... 60 5.1.3 Topographie Survey ...................................................................................... 60 5.1.4 Bed Material Sampling.................................................................................. 65 5.1.5 Hydraulic Modelling ..................................................................................... 67 5.1.6 Stability Analysis ..........................................................................................69 5.1.7 Discharge Data ................ ...... ............................................................... 70 5.1.8 Interpretation of Results ................................................................................ 71 5.2 Little Etobicoke Creek .......................................................................................... 73 Description of Design .................................................................................... 74 Preliminary Inspection .............................................................................. 76 Topographie Survey .....................................................................................