FLOOD00799

• Designation Number: 20
• County: Boulder
• Community: Boulder
• Stream Name: Boulder Creek
• Title: Special Flood Hazard Report - Boulder Creek
• Date: 5/1/1972
• Designation Date: 8/1/1972
• Floodplain - Doc Type: Floodplain Report/Masterplan

Pictures in this pamphlet illustrate the force and
extent of that great flood.
Other large floods occured in 1864, 1876,
1914, 1923, 1938 and 1969. About the flood of
21-23 May 1876, the Greeley Tribune reported
"The Boulder, swollen into a great river, in places
fully a mile and a half wide, inundated the land and
farms and meadows and swept away fences and
bridges." A floOd on 24 May 1914 resulted fro<i1
heavy rains that hastened the <i1elting of a deep
snowpack estimated at 50 percent above normal.
There are no stream gage records in the study
reach. From a study made by a consulting engineer
18 years after the 1894 flood and subsequent i~-
terpretations of the data, the peak discharge On
Boulder Creek at Boulder was estimated in the
9,000 to 13,000 cubic feet per second (c.f.s.)
range. A stream gage near Orodell, about 2 miles
upstream from Boulder, has been operated inter-
mittently from 1887 to 1916 and continuously
from 1916 to the present. The floods of 1923 and
1938 occured from inflow downstream of the
Orodell gage.

FUTURE FLOODS

The situation as regards the Boulder Creek

flood plain today was sagely foretold in a 1910
report" prepared for the BOulder City Improvement
Association of that time, by a noted professor in
the field of landscape architecture. His words "The
principal waterway in Boulder is Boulder Creek,
and its principal function, from which there is no
escaping, is to carry off the storm.water which
runs into it from the territory which it drains. If,
lulled .by the security of a few seasons of small
storms, the community permits the channel to be
encroached upon, it will inevitably pay the price in
destructive flood."
A defi~ite flood hazard exists at Boulder in the
Boulder Creek flood plain. A future flood of the
magnitude of that in 1894 would result in stagger.
ing residential, commercial, and municipal dam.
ages. No flood preventio~ measures that would
significantly reduce floodi~g at Boulder have been
constructed in the Boulder Creek basin. The sta.
tistical frequency of the 1894 flood is less than 1
in 100 chance of occurrenCe but such a flood could
happen in any year.
To identify the flood hazard at Boulder, two
potential large floods, the Intermediate Regional

"From THE IMPROVEMENT OF BOULDER COLORADO by Fred-
erick Law Olmsted. Jr., reprinted in May' 1967 as Bulletm 9 of
the Thorne E<;ological Foundatlon, Boulder, Colorado.