Urban stream restoration and the pigeon paradox

In Environment by Lenore NewmanLeave a Comment

Now that it has stopped raining again I am back to enjoying the wonderful landscape of Vancouver, and I had the chance to stop in and see how the wonderful stream daylighting project at Spanish Banks Creek is changing over time. It is a lovely place to find oneself on a nice summer day, though it really comes into its own in the fall when the salmon reappear. The idea of salmon in the city has intrigued me ever since I learned that huge swaths of salmon habitat has fallen to suburbanization in the lower mainland, leading to a sharp drop in local salmon runs. In short, if urban dwellers want to eat salmon, they need to make a little room for them. However the history of urban streams runs a little like this: we move into an area, use streams for water and waste disposal, pollute them with industry, allow them to catch on fire, (see the Kuyohoga river fire , for example) and then we get frustrated and get tired of cholera deaths and the like, and so we cover them over and channelize them. To undo this sort of damage isn’t environmentalism, it is a major engineering project that requires massive amounts of time, money and cooperation. Thus I have a special place in my heart for stream daylighters. In this case, the stream was brought out of a culvert and restored to its natural bed as salmon habitat.

To go from culvert to the little salmon paradise above took an astounding amount of effort. But interestingly, when my co-researcher interviewed the people involved they did not specifically list the environment as their prime motivation. They were more likely to talk about leaving something for their grandchildren, as restoring a neighbourhood asset, of creating a learning experience for urbanites. They see stream restoration as a socially generous act first and an environmentally generous act as an important but secondary consideration. This is interesting as it supports a rather obscure concept known as the “pigeon paradox”. Coined by Robert Dunn and his collaborators at the State University of Carolina, this concept argues that the future of wild spaces will be in the hands of a very urban world in which many people will have never seen the nature that we are asking them to protect. Little micro patches of nature such as the one above thus might indeed find their most critical role as an interface between “big nature” and “big city”. Stream daylighting projects , as I argue in a paper that has been in press so long that I wonder if I will live to see it emerge, improve habitat, provide cooling in urban areas, and raise property values, but they require a huge leap of faith. A person has to stand on asphalt and envision the stream trapped beneath, and then wrestle that stream back to life. There are hundreds of lost streams in the Lower Mainland, but few have been returned to life. In any case I liked the spot so much I sat by the stream for a while and answered email on my iphone, and listened to the water pass. Hopefully such projects will one day not be so rare.

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