Transforming Toronto’s Rivers: A Socio-Geomorphic Perspective

  • Peter Ashmore


Traditionally geomorphologists have examined the transformations of morphology of urban rivers entirely as physically determined human impacts and viewing urban river morphology as hybrid socio-geomorphic systems gives a fuller understanding of the changing urban riverscapes. In Toronto, the post-1950s institutional and policy powers, especially of the Conservation Authority and City, interacted with the regional landscape characteristics, rapid urban expansion and large storm events, and community visions to set rivers on a particular path of morphological transformation to their current state. Recent re-naturalization policies, and the scientific and commercial role of stream restoration practitioners, have produced novel technical riverscapes. Urban fluvial landscapes transcend natural-social distinctions and materialize physical processes combined with social processes and discourse reflecting both local and distal influences, contingencies, and events.



My research on urban rivers in Toronto has been supported by grants from Natural Resources and Engineering Research Council, and by City of Toronto, Toronto and Region Conservation Authority, Parish Geomorphic and Aquafor Beech Ltd. Thanks to John McDonald for preparing the aerial photographs for Fig. 23.1 and Karen van Kerkoerle for Figs. 23.2, 23.4, and 23.5. John McDonald and Mariane Ferencevic’s thesis work on Highland Creek is one of the things that first got me thinking about the ideas developed here and provided empirical support for some of the morphological and process transformations that I discuss. Belinda Dodson encouraged my thinking on this topic.


  1. Aquafor Beech Limited. 2008. Geomorphic systems master implementation project, highland creek, valley segment characterization report. Report submitted to City of Toronto.Google Scholar
  2. ———. 2009. Geomorphic systems master implementation project, highland creek watershed design charrette #2. Report prepared for City of Toronto.Google Scholar
  3. Ashmore, P. 2015. Towards a socio-geomorphology of rivers. Geomorphology 241: 149–156.CrossRefGoogle Scholar
  4. Ashmore, P., and Church, M. 2001. The impact of climate change on rivers and processes in Canada. Geological Survey of Canada, Bulletin 555.Google Scholar
  5. Ashmore, P., and B. Dodson. 2017. Urbanizing physical geography. The Canadian Geographer 61: 102–106.Google Scholar
  6. Bassnet, S. 2007. Visuality and the emergence of city planning in early twentieth-century Toronto and Montréal. Journal for the Study of Architecture in Canada 32: 21–38.Google Scholar
  7. Biron, P., T. Buffin-Bélanger, M. Larocque, G. Choné, C.A. Cloutier, M.A. Ouellet, S. Demers, T. Olsen, C. Desjarlais, and J. Eyquem. 2014. Freedom space for rivers: A sustainable management approach to enhance river resilience. Environmental Management 54: 1056–1073.CrossRefGoogle Scholar
  8. Bonnell, J. 2014. Reclaiming the don: An environmental history of Toronto’s don river valley. Toronto: University of Toronto Press.Google Scholar
  9. Bouleau, G. 2013. The co-production of science and waterscapes: The case of the Seine and the Rhône Rivers, France. Geoforum 57: 248–257.CrossRefGoogle Scholar
  10. City of Toronto. 2003. Wet weather flow master plan. Toronto: City of Toronto.Google Scholar
  11. Desfor, G., and J. Bonnell. 2011. Socio-ecological change in the nineteenth and twenty-first centuries: The lower don river. In Toronto’s waterfront, ed. G. Desfor and J. Laidley, 305–325. Toronto: University of Toronto Press.CrossRefGoogle Scholar
  12. Desfor, G., and R. Keil. 2000. Every river tells a story: The don river (Toronto) and the los angeles river (Los Angeles) as articulating landscapes. Journal of Environmental Policy and Planning 2: 5–23.CrossRefGoogle Scholar
  13. Desfor, G., and J. Laidley. 2011. Introduction. In Toronto’s waterfront, ed. G. Desfor and J. Laidley, 3–19. Toronto: University of Toronto Press.CrossRefGoogle Scholar
  14. Downs, P., and K.J. Gregory. 2014. River channel management: Towards sustainable catchment hydrosystems. New York: Routledge.Google Scholar
  15. Doyle, M.W., J. Singh, R. Lave, and M.M. Robertson. 2015. The morphology of streams restored formarket and nonmarket purposes: Insights from a mixed natural-social science approach. Water Resources Research 51: 5603–5622.CrossRefGoogle Scholar
  16. Eaton, B.C. 2013. Hydraulic geometry: Empirical investigations and theoretical approaches. In Treatise on geomorphology, ed. J. Shroder (Editor in Chief) and E. Wohl, vol. 9., Fluvial Geomorphology, 313–329. San Diego, CA: Academic Press.CrossRefGoogle Scholar
  17. Eden, S., and L. Holloway. 2013. More-than-urban ecosystems, socioecological flows and the problems with boundaries: A response to Francis et al. (2012). Transactions of the Institute of British Geographers 38: 678–681.CrossRefGoogle Scholar
  18. Eden, S., S.M. Tunstall, and S.M. Tapsell. 2000. Translating nature: River restoration as nature-culture. Environment and Planning D: Society and Space 18: 257–273.CrossRefGoogle Scholar
  19. Harris, R. 2004. Creeping conformity: How Canada became suburban, 1900–1960. Toronto: University of Toronto Press.Google Scholar
  20. Heynen, N., M. Kaika, and E. Swyngedouw. 2006. Urban political ecology: Politicizing the production of urban natures. In In the nature of cities: Urban political ecology and the politics of urban metabolism, ed. N. Heynen, M. Kaika, and E. Swyngedouw, 21–40. London: Routledge.Google Scholar
  21. Higgs, E. 2003. Nature by design. Cambridge: MIT Press.Google Scholar
  22. Karvonen, A. 2010. Metronatural™: Inventing and reworking urban nature in seattle. Progress in Planning 74: 153–202.CrossRefGoogle Scholar
  23. Kondolf, G.M., and C.-N. Yang. 2008. Planning river restoration projects: Social and cultural dimensions. In River restoration: Managing the uncertainty in restoring physical habitat, ed. S. Darby and D. Sear, 43–60. Chichester: Wiley.Google Scholar
  24. Lane, S.N., and K.S. Richards. 1997. Linking river channel form and process: Time, space, and causality revisited. Earth Surface Processes and Landforms 22: 249–260.CrossRefGoogle Scholar
  25. Lave, R. 2009. The controversy over natural channel design: Substantive explanations and potential avenues for resolution. Journal of the American Water Resources Association 45: 1519–1532.CrossRefGoogle Scholar
  26. ———. 2012. Fields and streams: Stream restoration, neoliberalism, and the future of environmental science. Athens: University of Georgia Press.Google Scholar
  27. ———. 2014. Freedom and constraint: Generative expectations in the US stream restoration field. Geoforum 52: 236–244.CrossRefGoogle Scholar
  28. ———. 2016. Stream restoration and the surprisingly social dynamics of science. WIREs Water 3: 75–81.CrossRefGoogle Scholar
  29. McClintock, N. 2015. Critical Physical Geography of urban soil contamination. Geoforum 65: 69–85.CrossRefGoogle Scholar
  30. McDonald, J. 2011. Response of river channel morphology to urbanization: The case of highland creek, Toronto, Ontario, 1954–2005. M.Sc. Thesis, University of Western Ontario.Google Scholar
  31. McDonald, A., S.N. Lane, N.E. Haycock, and E.A. Chalk. 2004. Rivers of dreams: On the gulf between theoretical and practical aspects of an upland river restoration. Transactions of the Institute of British Geographers 29: 257–281.CrossRefGoogle Scholar
  32. McHarg, I.L. 1969. Design with nature, 197. Garden City, NY: The Natural History Press, American Museum of Natural History.Google Scholar
  33. McLean, B. 2004. Paths to the living city: The story of the Toronto and region conservation authority. Toronto: The Toronto and Region Conservation Authority.Google Scholar
  34. Meshkova, L.V., P.A. Carling, and T. Buffin-Belanger. 2012. Nomenclature, complexity, semi-alluvial channels and sediment-flux-driven bedrock erosion. In Gravel-bed rivers: Processes, tools, environments, ed. M. Church, P.M. Biron, and A. Roy, vol. 424, 432. Chichester: John Wily and Sons, Ltd.Google Scholar
  35. Metropolitan Toronto and Region Conservation Authority. 1994. Valley and stream corridor management plan. Toronto, ON: MTRCA.Google Scholar
  36. Ness, T., and D.M. Joy. 2002. Performance of natural channel designs in Southwestern Ontario. Canadian Water Resources Journal/Revue canadienne des ressources hydriques 27: 293–315.CrossRefGoogle Scholar
  37. O’Neill, K.M. 2006. Rivers by design: State power and the origins of U.S. flood control. Durham: Duke University Press.CrossRefGoogle Scholar
  38. Ontario Ministry of Natural Resources. 1994. Natural channel systems: An approach to management and design. Toronto, ON: Ontario Ministry of Natural Resources.Google Scholar
  39. Parish Geomorphic. 2006. Highland creek valley segment 4A study; Characterization report. City of Toronto Report 2005–50, December 2006.Google Scholar
  40. ———. 2008. Highland creek valley segment 4/4A technical design brief. Report to City of Toronto, October 2008.Google Scholar
  41. Pasternak, G. B. 2013. Geomorphologist’s guide to participating in river rehabilitation. In Treatise on geomorphology, V.9, fluvial geomorphology, eds. J.F. Shroder (Editor in Chief), Wohl, E. (Volume Editor), 843–860. San Diego: Academic Press.Google Scholar
  42. Phillips, J. 2007. The perfect landscape. Geomorphology 84: 159–169.CrossRefGoogle Scholar
  43. Phillips, R.T.J., and J.R. Desloges. 2014. Glacially conditioned specific stream powers in low-relief river catchments of the Southern Laurentian great lakes. Geomorphology 206: 271–287.CrossRefGoogle Scholar
  44. ———. 2015. Glacial legacy effects on river landforms of the Southern Laurentian great lakes. Journal of Great Lakes Research 41: 951–964.CrossRefGoogle Scholar
  45. Revitalization News™. 2016. LA releases new planning tool for large, complex urban river restoration. Revitalization News™: The Journal of Economic, Social and Environmental Renewal, 30.
  46. Royal Commission on the Future of the Toronto Waterfront. 1988. Regeneration: Toronto’s waterfront and the sustainable city. Final Report.Google Scholar
  47. Sandberg, A., G.R. Wekerle, and L. Gilbert. 2013. The oak ridges moraine battles: Development, sprawl, and nature conservation in the Toronto region, 336. Toronto: University of Toronto Press.Google Scholar
  48. Schumm, S.A. 1991. To interpret the earth: Ten ways to be wrong, 133. Cambridge: Cambridge University Press.Google Scholar
  49. Simpson, G.G. 1963. Historical Science. In The fabric of geology, ed. C.C. Albritton, 24–48. Stanford, CA: Freeman, Cooper and Co.Google Scholar
  50. Tadaki, M., G. Brierley, and C. Cullum. 2014. River classification: Theory, practice, politics. WIREs Water 1: 349–367.CrossRefGoogle Scholar
  51. Toronto and Region Conservation Authority. 2014. The living city® Policies for planning and development in the watersheds of the Toronto and region conservation authority. Toronto: TRCA.
  52. Trudeau, M.P., and M. Richardson. 2015. Change in event-scale hydrologic response in two urbanizing watersheds of the great lakes St Lawrence Basin 1969–2010. Journal of Hydrology 523: 650–662.CrossRefGoogle Scholar
  53. Vocal-Ferencevic, M., and P. Ashmore. 2012. Creating and evaluating DEM-based stream power maps as a stream assessment tool. River Research and Applications 28: 1394–1416.CrossRefGoogle Scholar
  54. Waley, P. 2000. Following the flow of Japan’s river culture. Japan Forum 12: 199–217.CrossRefGoogle Scholar
  55. ———. 2005. Ruining and restoring rivers: The state and civil society in Japan. Public Affairs 78: 195–215.Google Scholar
  56. Waley, P., and E.U. Aberg. 2011. Finding space for flowing water in Japan’s densely populated landscapes. Environment and Planning A 43: 2321–2336.CrossRefGoogle Scholar
  57. Whatmore, S. 2002. Hybrid geographies: Natures cultures spaces, 225. London: Sage Publications.Google Scholar

Copyright information

© The Author(s) 2018

Authors and Affiliations

  • Peter Ashmore
    • 1
  1. 1.Department of GeographyUniversity of Western OntarioLondonCanada

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