ich undoubtedly in the long run--as in the long past--will
prove to be the most valuable tool for reducing these damages, for it
will bring about a restriction on ill-advised and uneconomic
encroachment in these streamside areas.

The reason most such encroachment is bad, with or without a dam
upstream, with or without levees, is that it establishes the certainty
of further and larger flood damages in the future, with the certainty of
further and larger expenditures to combat them. It has been pointed out
that no such thing really exists as flood _control_, but only a given
degree of flood _protection_. Economics and technology dictate that
reservoir capacities devoted to the storage of flood water, for example,
be considerably smaller than the maximum runoff conceivably possible.
This means that sooner or later there is going to be a great flood
against which the reservoir or reservoirs will not suffice. If the
reservoirs' presence, as is most often the case, has directly encouraged
a lot of flood plain speculation and construction downstream, then the
great flood is going to do more damage than was ever done before, and
more reservoirs and other protective measures, most often Federally
financed, are going to be demanded, at a price that rises sharply as
less desirable sites and methods have to be employed, and with
frequently catastrophic scenic effects. These considerations apply to
small watersheds as well as large ones.

This costly cycle, which frequently makes the general public pay both in
tax money and the sacrifice of amenities to protect the investment of a
relatively few who profit from the wrong kind of flood plain use--in
plain words, makes the public subsidize their ventures--has established
itself widely. In some places, of course, certain kinds of development
can take place only on the flood plain, and planning for its structural
protection may be amply warranted, with equitable cost-sharing. But the
difference between this sort of flood plain use and the much more
common, thoughtless, quick-profit type needs to be more widely
recognized and established in policies at all levels of government. The
subject has been much studied. In August 1966 the findings of a
distinguished Task Force on Federal Flood Control Policy, which made
detailed recommendations for injecting some sense into the situation,
were submitted to the attention of Congress by President Johnson. At the
same time, he issued Executive Or