1988-04-20_PERMIT FILE - C1981008A

• Permit No: C1981008A
• IBM Index Class Name: PERMIT FILE
• Doc Date: 4/20/1988
• Doc Name: Sedimentation Pond 005
• Section_Exhibit Name: Tab 13 Attachment E
• Media Type: D
• Archive: Yes

The curve number and "k" factor for Pond 005 was determined as a
weighted average.
TABLE 4
Weighted Curve Number (CN)
Vegetation Hydrologic Area
Cover Soil Group CN (Acres) CN (X) Area
Upland Sagebrush-
Grass D 85 13 1105
Reclaimed Area C 81 18 1458
31 ac. 2563
wt. CN = 2563 = 82.7 Use 83
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TABLE 5
Weighted "k" Factor Calculations
Area
Soil Type "k" Factor (Acres) "k" (X) Area
9904 0.22 13 2.86
Reclaimed 0.25 18 4.50
31 ac. 7.36
wt. "k" factor = 7.36 = 0.237 Use 0.24
Precipitation and Storm Type
Precipitation depths for the 10-year, and 25-year storms were developed
using procedures and data published in the Soil Conservation Service
publication "Procedures for Determining Peak Flows in Colorado". A
standard SCS Type II storm was utilized for each analysis.
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