f
modern technology to rivers in the past half-century of our national
growth has not always had happy results. "A river," Justice Holmes once
wrote, "is more than an amenity, it is a treasure." His feeling is
shared by thousands upon thousands upon thousands of people who live
along the Potomac and its tributaries or who go there to float down them
in bass time, to picnic and swim, to hunt, to dig into the region's
history, or just to listen to the purl of green water against the rough
stonework of a ruined bridge pier. Deteriorated though a few stretches
may presently be, these rivers are still treasures.

The lack of development also presents planners with a fairly clean slate
on which to write. In terms of water, few massive human mistakes
confront them except the pollution of the upper estuary and certain
other reaches like the afflicted North Branch. Therefore they can begin
more or less from scratch and can usually find various choices for
action against the water problems of the Basin--against pollution,
against flood damages, and against impending or existing shortages of
water for municipal and industrial use.

[Illustration]

Though for clarity in discussion we need to classify these various kinds
of problems separately, in practice they do not so neatly divide from
one another. Nor do they divide from the way the land in the Basin is
used or from the pleasure and fulfillment people find in the outdoors.
If a region's use of a stream's water is heavy in a dry August, for
instance, whatever pollution the stream gets below towns and factories
will be more concentrated and damaging than if the stream were flowing
well. Pollution itself can affect the utility of water as well as
people's enjoyment of it in a stream. A creek watershed that has been
ignorantly farmed or roughly assaulted with bulldozers for urban
development is an eyesore of erosive destruction, unproductive of crops,
wildlife, or poetic appreciation, and can cause both heavier stream
flooding in time of storm and lower 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 par