FLOOD10942

• County: Statewide
• Basin: Statewide
• Title: Colorado Water Conservation Board - 2001 Colorado Flood Documentation Report
• Floodplain - Doc Type: Flood Documentation Report

SEITIIISIX

New Castle

The watershed most affected by these flood events was the Colorado Headwaters-Plateau basin
(shown in Figure 6.1-3).

Figure 6.1-3
Colorado Headwaters Plateau Watershed

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6.2 STORM EVENT DATA

6.2.1 Precipitation Data

Mr. Steve Rippy, the New Castle Town Manager, reported that approximately 1.5 inches of
rainfall fell in approximately 15 minutes and a NOAA event record reported one inch in less than
20 minutes. A comparison of the data mentioned above and the precipitation-duration-frequency
curves (developed from the u.s. Department of Commerce, NOAA Atlas 2, Volume 111-
Colorado) indicates that the August 14, 2001 event was approximately equivalent to a 100-year
frequency event. Figure 6.2-1 below illustrates precipitation versus duration for several return
periods for rainfall in New Castle, Colorado.

Figure 6.2-1
Precipitation-Duration-Frequency Curves for New Castle, Colorado

New Castle, CO
--+- 2
2.5 ----- 5
-
~ 2.0 ---.- 1 0
s:: 25
.2 1.5
...... --*- 1 00
ns
.9- 1. 0 ----200
(J
cu
.... 0.5 -+- 300
a..
0.0 -500
0 2
Duration (hr)

URS

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