FLOOD01759

• County: Broomfield
• Community: Broomfield
• Title: Flood Insurance Study - City and County of Broomfield, CO
• Date: 11/25/2003
• Prepared For: Broomfield
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

The areas studied by detailed methods were selected with priority
given to all known flood hazard areas and areas of projected
development or proposed construction through March 1990.

The scope of study has
streams that were studied

been revised
by approximate

to describe
methods:

the

following

Mustang Run
Preble Creek
South Fork Preble Creek
Sack Creek

This flood information was provided by the U, S, Department of the
Interior; Bureau of Reclamation, under Inter-Agency Agreement
No, EMW-90-E-3456, as part of the Limited Map Maintenance Program,

2.2 Community Description

Most of Broomfield is located in Boulder County, although portions
are situated in Adams and Jefferson Counties. Broomfield is located
in north-central Colorado, on the eastern slope of the Rocky
Mountains, approximately 13 miles north of Denver. In 1970, the
population of Broomfield was 7,161; at the end of 1980, the
population was 20,730 (Reference 1). Continued growth is expected-
for the City of Broomfield.

City Park Channel, Nissen Reservoir, Gay Reservoir, and the
West Lake Reservoir drain a total area of approximately 8.4 sg~ar~
mrres-and-dre-5ounaea-on-fne northwest by a rise at an elevation of
approximately 5,400 feet. The streams generally flow southeasterly,
emptying into Big Dry Creek at an approximate elevation of
5,200 feet. The drainage boundaries of the individual basins are
indistinct, being located at the crests of the east-west rolls of
the high plains. The creeks are generally shallow, with no distinct
channels.

The climate of the area features low relative humidity, low
rainfall, moderate to high winds, and a large daily range in
temperature. Temperatures range from a high of 102 degrees
Fahrenheit (oF) to a low of -260F at Rocky Flats, The average
maximum and minimum temperatures are 60.20oF and 39.10oF,
respecti vely. The average annual precipitation at Rocky Flats is
15.14 inches. Sixty-nine percent of the precipitation occurs
between April and September. Summer precipitation is largely from
thunderstorm activity and is sometimes extremely heavy.

Typical area soils are composed mostly of the Nunn, Platner, and
Renshill series, as defined by the U ~ S. Soil Conservation Service
(SCS) . These soils are generally well drained, nearly level to
moderately sloping formations of loamy alluvial material. Slopes
vary from 0 to 9 percent, and the natural vegetation is grass,
although most undeveloped areas are cultivated. The permeability of
these soils is moderate to slow (Reference 2).

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