PROJ00462

• Contract/PO #: FS0036X
• Contractor Name: Idaho Springs, City of
• Contract Type: Loan
• Water District: 0
• County: Clear Creek
• Loan Projects - Doc Type: Feasibility Study

2. Floods from design general-type storm,
~,. "

(a) Inflow design flood, probable maximum
general storm.

(1) From Figure 17, Page 50: Zone C
Probable maximum 6-hour point
vaIues in inches for generaI type
. storms west of the 1050 meridian.
6 inches.

(2) From Figure 19; General Storm:
Conversion ratio from 6-hour point
rainfall to 6-hour area rainfall for
area west of 1050 meridian
Ratio = area rainfall .;. point rainfall
O. 995 = area rainfall .;. 6
or area rainfall = 5.97 inches

(3)(4) (5) From Figure 18, Page 51,
Table 1, Page 52

Time % of Accum. Increm.
Ending 6-hr PMP, PMP,
Hr. PMP inch. inch.
1 48 2.87 2.87
2 65 3.88 1.01
3 76 4.54 0.66
4 85 5.07 0.53
5 93 5.55 0.48
6 100 5.97 0.42
7 1.07 6.39 0.42
8 1.14 6.81 0.42
9 1.20 7.16 0.35
10 1.26 7.52 0.36
11 1. 31 7.82 0.30
12 1.36 8.12 0.30
13 1.395 8.33 0.21
14 1.43 8.54 0.21
15 1.465 8. 75 0.21
16 1.50 8.96 0.21
17 1.535 9.16 0.20
18 1.57 9.37 0.21

2

1

6
5
4
3
2
1
6
4
3
1
2
5
1
2
3
4
6
5

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