Environmental Engineering Reference
In-Depth Information
the dams without even knowing it.There is a piece of folklore in the Pacific
Northwest which, like any good piece of folklore, cannot be killed by a his-
torian like me. It is the folklore of Bonneville Dam, which supposedly was
originally designed without any provision for fish to pass upstream. The
origins of this story, as far as I can tell, are in an artist's rendition of the dam
that did not include fish ladders. But the plans for the original dam not only
included fish ladders, they included fish elevators. The dam had redundant
systems to move fish upstream. What the planners failed to consider ade-
quately was how to get them back downstream.
The reason the “no fish ladder story” is so persistent is that it is so com-
forting.Why are we in such a mess? It is because engineers, technicians, politi-
cians, and industrialists ignored and defied nature. We, on the other hand,
know that we must mimic nature and follow nature if we are to succeed. But
this is precisely what many of the engineers who built the dams thought. Carl
Magnusson, an engineer who taught at the University of Washington and was
one of the main promoters of Grand Coulee Dam, put it this way:
The dam will accomplish intentionally the result achieved capriciously, by all the
rampant natural forces of the Pleistocene period. It will raise a portion of the
Columbia back into the Coulee, and again the floor of the ancient gorge will be
inundated. After being dry and arid throughout almost all the history of mankind,
the Grand Coulee once more will be a waterway.
Magnusson was right, once an ice dam had blocked the Columbia and
forced water into the Grand Coulee. All kinds of things happen in nature.
Mimicking nature is not necessarily always a safe course. Distinguishing
between good and bad technologies on the basis of their resemblance to
natural processes is not a reliable guide. It is a logic that has sometimes
caused the problems we seek to solve.
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The issue is, however, more complicated than this. The designs were
flawed in that they produced unintended consequences, but some of those
consequences turned out to be desirable. Many of the environments that
people in the United States now treasure as natural are actually contingent
environments that are the results of human manipulation. A hundred years
of intense environmental manipulation in the Pacific Northwest has cre-
ated, for example, irrigation systems whose very inefficiencies have created
pothole lakes and wetlands which host abundant migrating waterfowl and
irrigation ditches with trout and kokanee and beaver and muskrat. These
