FLOOD07468

• County: Statewide
• Community: State of Colorado
• Stream Name: All
• Basin: Statewide
• Title: The Design of Encroachments on Floodplains Using Risk Analysis
• Date: 10/1/1980
• Prepared For: USDOT
• Prepared By: Federal Highway Administration
• Floodplain - Doc Type: Educational/Technical/Reference Information

TABLE 7.1a - Overtopping Data e
Di scharge Frequency Overtoppi ng Percent Loss
cfs yr Depth (ft) Time (hr) Embankment Pavement
20,000 10 0 0 0 0
25,000 25 0 0 0 0
30,000 50 0.2 7 0 0
35,000 100 0.7 20 3 7
40,000 200 1.3 40 17 23

The roadway is 2-1ane with a 10-foot shoulders and 3:1 side slopes. At elevation
153, the embankment volume for 2900 feet of roadway is 10,740 CY and the
pavement area is 7,733 SY. For the 50-year event, roadway clean up is necessary.
This is assumed to cost $2,000.

TABLE 7.1b - Roadway Losses

Disch arge Frequency
cfs yr
20,000 10
25,000 25
30,000 50
35,000 100
40,00 200

Embankment (CY)

Losses
$ Pavement(SY)

$

e

296.4
1,679.7

673

324.8
1,067.2

5,700
18,729

3,813

Total Roadway Repairs are:

(LAR)50 = $2,000
(LAR)100 = $673 + 5,700 = $6,373
(LAR)200 = $3,812 + 18,729 + 5,000 = $27,542

e

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