The Nations River | Page 9

flow in time of drought by the way its disruption
alters the normal behavior of rainwater. The silt that storms wash off of
it is not only a major ugly pollutant of flowing water below that point
but can complicate flooding and bank-cutting and navigation and other
things by settling out into bars and shoals in still stretches, including
reservoirs.
All of these things, and others as well, have to be considered together
as parts of a whole problem. And that problem is that men's hugely
increasing numbers and their multiplying technological power over
their environment have made it necessary to readjust the balances
somewhat in great natural units like river basins--to restore, manage,
and protect them in such a way as to be able to hand them over decent
and whole and useful to the people who come after.
Problems of Water Supply in the Potomac Basin

Wisely handled, the water that runs annually through the streams of the
Potomac river system can be counted on to satisfy any demands that
people there are likely to make on it in present times or during the
foreseeable future. More than 2-1/2 trillion gallons of fresh water
normally flow down the Potomac in a year. It would be pleasant to
believe that this means that the natural and unassisted river system is
going to continue to serve human needs in the future as it has served
them heretofore--that after cleaning up the network of streams and
ensuring against their repollution and the desecration of their landscape,
men will be able to leave them respectfully alone to run down toward
the Chesapeake Bay as they have run during and before human
memory.
However, it is not so. Whatever human population might be considered
ecologically tolerable under natural conditions for the nine million or
so acres of earth, rocks, vegetation, and water that make up the Basin, it
has long since been exceeded by hundreds on hundreds of thousands.
And if those who predict such things are right, it is going to be
exceeded much further in the near and middle future. Today's
approximately 3.5 million Basin inhabitants are expected to double by
the turn of the century, with accompanying complex shifts in the ways
they will be making their livings and in the numbers of them who will
live in the country as compared with the cities and towns. Thereafter,
further geometric increases are contemplated, calmly by some
contemplators and less so by others.
As a result of past and present populations and their activities,
conditions in the Basin--including the river system--are necessarily far
from natural, for specific structural development is not the only form of
change. The Potomac environment has been adapted to man's use, and
in places where that use has been unreasonable it is already in trouble.
Clearly it is going to have to be manipulated artificially to some extent
to meet people's demands on it and to guard it against the worst effects
of their numbers. In fact, very luckily, it already is being so
manipulated in dozens of ways ranging from methods of farming and
forest management to sewage treatment. It is possible to hope that
present population forecasts may somehow find less than ample

fulfillment, but it is not possible to count on it for planning purposes.
Nor is it possible to wish out of existence situations already serious.
[Illustration: WATER SUPPLY POTOMAC RIVER, WASH. D.C.]
At times during the hot months of drouthy 1966, the climax of a dry
cycle that had begun to develop five years earlier, the Washington
metropolis was not too far from the bottom of its water barrel. The
situation was not as bad as in some other Northeastern regions, nor as
bad as some local analyses claimed, but it was bad enough. The highest
daily withdrawal of the year was on June 26, when the metropolitan
water intakes in the Potomac sucked out approximately 380 million
gallons. Of this some 30 million gallons had to do with a pumping
pattern pertinent to adjustments within the system, and the other 350
million went for the use and refreshment of a metropolis afflicted by
summer's heat. The total figure represented less than half of the river's
flow at that time.
[Illustration: GROUND WATER LEVELS WASHINGTON, D.C.
AREA]
For a couple of days in September, however, the Potomac's flow
reached an all-time low of about 390 million gallons a day. Even if the
demand on those days had risen as high as in June, which it did not,
there would still have been an excess, but not a very safe one. Heavy
storms shortly thereafter eased the situation, and rainfall since then has
definitely broken the long drought pattern, returning stream and
groundwater levels to normal.
The sober fact is that the Washington metropolis is