FLOOD09853

• County: Denver
• Community: Denver
• Stream Name: South Platte River
• Basin: South Platte
• Title: Effects of the May 5-6, 1973 Storm in the Greater Denver Area
• Date: 12/31/1973
• Prepared For: State of Colorado
• Prepared By: USGS
• Floodplain - Doc Type: Flood Documentation Report

FIGURE 19. - Gullying on a steep hillside previously denuded of vegetation and topsoil.

and prevent unforeseen geologic complications.
Blockage of natural drainageways was one
of the principal causes of flood damage in the
Greater Denver area. Many bridges and culverts
were simply unable to accommodate the in-
creased runoff; many were blocked with trash
or sediment. In the urban environment, natural
drainageways that seem unsuitable for one pur-
pose or undesirable from one point of view may
enhance the value of an area for something
else, Most natural landscape features have the
potential for being either liabilities or assets.
During a major storm, an urbanized or indus-
trialized flood plain is likely to be a liahility,
not only because of direct flood damage to fa-
cilities on the flood plain but also because of the
obstructions that such facilities present to the
free passage of the water, Such facilities, in
other words, can actually intensify the effects
of flooding, But a flood plain that is dedicated
as parkland, open space, or wildlife habitat in

an otherwise crowded city is nearly immune to
flood damage and is likely to become a com-
munity asset that increases in value with time.
Overland Park on the South Platte flood plain
is a good example. The numerous ravines and
gullies that drain the Greater Denver area
ought to be natural assets that enhance the
quality of urban living, but many of them are
financial liabilities to the community and some,
regrettably, are festering eyesores. Protecting
natural drainageways should be a prime con-
sideration of long-range planning. Existing
structures that tend to obstruct drainage might
well be phased out of use. Unobstructed drain-
ageways not only afford insurance against storm
damage from high runoff but they provide some
of the open space that is fast disappearing from
the urban scene.
Damaging floods are not restricted to streams
that have broad flood plains. Indeed, an urban
drainageway need not have any flood plain at

19