FLOOD07425

• County: Boulder
• County: Weld
• Community: Boulder, Weld County
• Stream Name: Coal Creek, Rock Creek
• Basin: South Platte
• Title: Flood Hazard Analyses
• Date: 10/1/1976
• Prepared For: Weld County
• Prepared By: USDA Soil Conservation Service
• Floodplain - Doc Type: Floodplain Report/Masterplan

DESCRIPTION OF THE STUDY AREA

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the C
Parts
The 1
1 ittl
10,50
joins

cated primarily in the southeastern portion of Boulder County,

Creek and Rock Creek Watershed drains about 79 square miles.

the drainage area lie within Jefferson, Adams, and Weld Counties.

gth of the watershed Is about 28 miles and average In width of a

less than 3 miles. Upper reaches of the watershed begin at

mean sea level elevation. The lower end of the watershed

oulder Creek at about the 4,954 feet elevation.

e upstream drainage area originates in the foothills east of the

Rocky ountains and the geology Is characterized by a series of folded

and fa lted sedimentary strata. For the 'most part, the strata are

classi led as the Fox Hills Sandstone and Laramie formation. The soils

are s llow, very gravelly and stony, and are in the rock outcrop-Juget-

Balle association. The ground cover consists of native grass and

woodla d. Except for a narrow fringe of Rocky Mountain juniper, Ponderosa

pine kes up the bulk of the woodland cover. The woodlands are very

pictu sque and most of the area is used for grazing and homesites.

Both ar-around homes and summer homes are growing in popularity.

Averag annual precipitation Is about 18.5 inches and the normal mean

tempe ture Is 51.8 degrees. Extremes of annual precipitaLlon have

varied from a maximum of 29.09 inches in 1938 to a minimum of 10.91

inches In 1954. The mean maximum and minimum temperatures in July are

85.3 a d 59.0 degrees, respectively.
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