FLOOD04641

• County: Denver
• Community: All
• Stream Name: All
• Basin: South Platte
• Title: Proposed Hydrology for use in Hydraulic Analysis of FEMA Flood Studies and Restudies
• Date: 9/1/1989
• Prepared For: State of Colorado
• Prepared By: Resource Consultants
• Floodplain - Doc Type: Educational/Technical/Reference Information

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TA8LE 13.2 -=- SUMMARY OF JCT BASIN PARAMETERS

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DRAINAGE AREA CURVE NUMBER TIME OF
SUBBASIN ~~ miles) .Qll CONCENTRATrON. Ie
1 0.36 76 0.55
2 0.91 70 1.19
3 1.01 69 1.15
I, 0,1,2 69 0.66
5 1. 23 72 1.03

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The res"l ting peak flows at key pol nts indicated in Figure 13.1
are summarized in Table 13.3. These peak flows appear to be
slightly less than the peak flows developed in the Wilson and
Company report, but are consistent wIth peak flows developed
for oth,ar basins In the El Paso County area. The peak flow at
the mouth of 2,780 cfs appears consistent with other studies
done in this basin.

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IllBLE 13.3 .:. SUMMARY OF JCT PEAK DISCHARGES BY RCI

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DRAINAGE AREA PEAK DISCHARGES(l) ~
LOCATION (square mUes) 10 YR 50 YR 100 YR 500 YR
JCT 1 3.93 1,160 2,280 2,780 4,500
JCT 2 3.57 1,070 2,150 2,620 4,300
JCT 3 2.66 810 1,640 1,990 3,300
JGT 4 1. 65 560 1,140 1,380 2,300

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The Crystal Creek (CC) watershed is located northeast of the
town of Monument, Colorado (22 miles north of Colorado
Springs}. More than 85% of the basin is east of Interstate 25
as shown in Figure 14.1. The creek generally flows south to
the Interstate where it makes a bend and then continues in a
more westerly direction.

(1) These vahws result from the 2-hour AMC III storm.

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14.0 CRYSTAL CREEK HYDROI.OGY

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14.1 WatershE!d Description

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Total a:rea of the basin Is 0.78 square miles. Average slopes
are from 4 to 6% with steeper slopes up to 15% occurring on the
western hillsides. The hIghest point in the northeastern
corner ls 7,500 feet. The lowest elevation just west of the
Denver and Rio Grande Railroad is at 6,960 feet. Total length
of the creek from its headwaters to this point is approximately
2.5 milE:s.

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Development in the watershed consists mainly of large
residential lots averaging 1 to 5 acres in size. A small
amount of commercial activity exists at the western tip of the

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R€~OURC€ CON~ULTf\NT~ INC

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