PERMFILE120564

• Permit No: C1981020A
• IBM Index Class Name: Permit File
• Doc Date: 11/4/2002
• Section_Exhibit Name: Appendix M‎(i)‎ to M‎(viii)‎
• Media Type: D
• Archive: Yes

• ESTIMATE OF FLOOD CHARACTERISTICS FOR WATERSHED C -
MUNGER CREEK TRIBUTARY BELOW WASTE ROCK
DISPOSAL SITE, MUNGER CREEK DRAINAGE BASIN
GARFIELD COUNTY, COLORADO
Procedure for ungaged sites with streams located entirely in
one flood - characteristic region:
1 - Identify flood region: Southern Plateau Region (From Figure
2) .
2 - Select regression equations for peak discharges and depths
of selected recurrence - interval floods: See Table 1
3 - Compute Basin and Climate parameters required for 3:
Drainage Area A = 0.83mi2 (planimetered)
•
4 - Solve Equations:
•
Peak Discharges of RI Floods
Q10 = 59.7 (.83)•709 = 52cfs
Q50 - 89.1 (.83)'709 = 78cfs
Q100 = 103 (.83)'710 = 90cfs
Q500 = 137 (.83)'713 = 120cfs
STD Error, of Estimate 8
Average Range
47 +58 to -36
50 +62 to -38
53 +66 to -40
65 +84 to -46
Depths of RI Floods
D10 = 1.25 (.83)•261 = 1.2 ft
D50 = 1.54 (.83)•254 = 1.5 ft
D100 = 1.64 (.83)'254 = 1.6 ft
D500 = 1.98 (.83)•239 = 1.9 ft
25 +28 to -22
34 +40 to -28
36 +42 to -30
44 +53 to -35
Reference: CWCB Technical Manual No. 1, 1976