Environmental Engineering Reference
In-Depth Information
4
Hydropower
Bureaus build roads into new hinterlands, then buy more hinterlands to absorb the
exodus accelerated by the roads. A gadget industry pads the bumps against nature-in-
the-raw; woodcraft becomes the art of using gadgets. And now, to cap the pyramid of
banalities, the trailer. To him who seeks in the woods and mountains only those things
obtainable from travel or golf, the present situation is intolerable. But to him who seeks
something more, recreation has become a self-destructive process of seeking but never
quite finding, a major frustration of mechanized society.
—Leopold (1949)
When we speak of water and its many manifestations, we are speaking of that end-
less quintessential cycle that predates all other cycles. Water is our most precious
natural resource; we can't survive without it. There is no more water today than there
was yesterday—that is, no more this year than there was 100 million years ago. The
water present today is the same water used by all the animals that ever lived, by cave
dwellers, Caesar, Cleopatra, Christ, da Vinci, John Snow, Teddy Roosevelt, and the
rest of us—again, there is not one drop more or one drop less of water than there
has always been. This life-giving cycle, a unique blend of thermal and mechanical
aspects, is dependent on solar energy and gravity (see
Figure 4.1
) for its existence.
Nothing on Earth is truly infinite in supply, but the energy available from water
sources, in practical terms, comes closest to that ideal (Spellman, 2008).
THE RACHEL RIVER
*
The Rachel River, a hypothetical river system in the northwestern United States,
courses its way through an area that includes a Native American reservation. The
river system outfalls to the Pacific Ocean, and the headwaters begin deep and high
within the Cascade Range in the state of Washington. For untold centuries, this
river system provided a natural spawning area for salmon. The salmon fry thrived
in the river and eventually grew the characteristic dark blotches on their bodies and
transformed from fry to parr. When the time came to make their way to the sea,
their bodies larger and covered with silver pigment, the salmon, now called smolt,
inexorably migrated to the ocean, where they thrived until time to return to the river
and spawn, about 4 years later. In spawning season, the salmon instinctively headed
toward the odor generated by the Rachel River (their homing signal) and up the river
to their home waters, as their life-cycle instincts demanded.
*
Adapted from Spellman, F.R. and Whiting, N.E.,
Environmental Science and Technology
, 2nd ed.,
Government Institutes, Rockville, MD, 2006.
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