FLOOD04800

• County: El Paso
• Community: Colorado Springs
• Stream Name: Cottonwood Creek
• Basin: Arkansas
• Title: Engineering Study of Cottonwood Creek Drainage Basin
• Date: 8/7/1979
• Prepared For: Colorado Springs
• Prepared By: Lincoln Devore
• Floodplain - Doc Type: Floodplain Report/Masterplan

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water entry and are expansive. The majority of clay and clayey soils

appear to be found in the south and west portions of the basin. The

area between union Blvd. and Interstate 25 contains numerous large

clay and clayey lenses .and can be considered quite erratic as to

soil type.

The western portion of the basin con-

tains large areas of alluvium deposited' along the major stream beds,

In the streams which carry water most of the year, this alluvium

consists primarily of sands, some gravel, and silts. Smaller inter-

miltant streambeds contain relatively large amounts of clay. The

soils in the area are, of course, mostly mixtures of these various

soil types. Most of this alluvium is dated as the Pinery Creek

Alluvium. For the most part, the sandy alluvium and some of the

silts have the hydrologic 'A' classification. Siltier and clayey

alluvium and the weathered clayey sands have a hydrologic 'B'

classification. The deposits of clays, sandy clays and hard sand-

stones have a hydrologic 'C' or 'D' classification depending on pre-

cise constituents and hardness, Some wind blown (aeolian) sands

have been found on the slope south of CottonWOOd Creek and in Basin

B and the mid portion of Basin A. The hydrologic classification of

this soil depends primarily on the depth of deposit.

The depth of weathered soil and alluvium

are quite variable. This has a considerable effect on basin flow.

Deeper weathered sands and sandy alluvium in the upper basin have a

tendency to store water deeply by infiltration during rainfall periods.

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