FLOOD02815

• Designation Number: 280
• County: El Paso
• Community: Monument
• Stream Name: Crystal Creek & Dirty Woman Creek
• Basin: Arkansas
• Title: Flood Hazard Identification Report - Crystal Creek and Dirty Woman Creek, Monument, Colorado
• Date: 2/1/1987
• Designation Date: 5/1/1987
• Floodplain - Doc Type: Floodplain Report/Masterplan

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STUDY AREA DESCRIPTION

Drainage Basin Characteristics

Crystal Creek is an ephemeral stream with significant flows only
during or after a rainstorm, Headwaters of Crystal Creek are located at
approximately elevation 7,280 feet above mean sea level. The highest
point in the bas in is at 7,500 feet. The mouth of Crysta 1 Creek is its
confluence with Monument Lake at elevation 6915 feet, The creek begins
by heading south-southwesterly and then southwesterly after it crosses
Interstate 1-25 to its mouth. The length of Crystal Creek from its
headwaters to its confluence with Monument Lake is approximately 2.5
mil es, The dra inage area of Crysta 1 Creek to just above its conf1 uence
with a sma 11 tributary (approx imate 1y 600 feet downstream from the D&RG
railroad tracks) is 0,75 square miles, (See Basin Map, Plate 1),

Headwaters of Dirty Woman Creek are located at approximately 7430
feet above mean sea level with the highest point in the basin at
elevation 7510 feet. The creek travels predominantly west until it
crosses Interstate 1-25 where it begins flowing southwest, The length of
Dirty Woman Creek from its confluence with Monument Creek is
approximately 4,3 miles. The drainage area of Dirty Woman Creek to its
intersection with Mitchell Road (at the Town of Monument's western limit)
is 5,0 square miles,

Study Reach Description

The study reach along Crysta 1 Creek extends from just downstream
from interstate 1-25 to Monument Lake. Study limits are shown on Figure
2, the Plate Index, This reach covers a length of 1.0 mile of which
approximately 0,6 mile is within the Town of Monument's corporate limit.
The land is predominantly undeveloped in the portion of the creek
downstream from 1-25, There is no distinct channel in the most
downstream reach,

The study reach along Dirty Woman Creek extends from the southbound
interstate 1-25 access ramp (from route 105) to Mitchell Road (Monument's
downstream corporate limit), No detailed contour mapping exists for the
length of the creek downstream from Mitchell Road; thus this portion was
not studied, Study limits are shown on Plate 2, the Plate Index, This
reach covers a length of 1,0, mile of which approximately 0,1 mile is in
the current corporate 1 imit for Monument, The land is undeveloped with
the exception of Dirty Woman Creek Park, which encompasses all of the
land adjacent to Dirty Woman Creek within the Town I s corporate 1 imits,
There is no distinct channel through most of the reach,

The study reaches were included in the Federal Emergency Management
Agency's Flood Insurance Rate Map (FIRM) for unincorporated E1 Paso
County, dated December 18, 1986, The FIRM is shown in Exhibit 2, The
flood boundary shown on this map was derived using approximate methods.

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