PERMFILE66486

• Permit No: C1981020A
• IBM Index Class Name: Permit File
• Doc Date: 5/13/2002
• Section_Exhibit Name: Volume 6 APPENDIX As TO Cs
• Media Type: D
• Archive: Yes

Asc-2
SEDIMENTATION RESERVOIR
• NAME: REFUSE DISPOSAL AREA - STOCKPILE - PHASE IV
I. RUNOFF AND VOLUMES
Determine:
Maximum runoff area and peak discharge
Reservoir liquid volume
Reservoir sediment volume
Total reservoir volume
Area: 29.84 Ac of disturbed area for the stockpile - use
30.0 Ac
Precipitation:
P10 = 1.7 inch(es) (10-year, 24-hour precipitation
event from the Precipitation-Frequency Atlas
of the Western United States, Volume III - Col-
orado)
P25 = 2.1 inch(es) (25-year, 24-hour precipitation
event from the Precipitation-Frequency Atlas
of the Western United States, Volume III, Col-
orado)

e CN~Ave = 80
Assume Antecedent Moisture Condition (AMC) II
s 1CN0 - 10 (SCS Method)
s = 1800 - 10 = 2.50
Runoff:
2
Q10 -(P10 - 0.25) _ (1.7 - 0.2 (2.50)]2
Pi0 + 0. S .7 + 0.8 ( .50 = 0.39 inch
2
Q25 =(P25 - 0.25) _ [2.1 - 0.2 (2.50)J2 = 0,62 inch
P25 + 0.8S •7 + ( .50)
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