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Major Flooding Impacts Carlsbad
and Eddy County.
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| The Eddy County flood survey revealed that three different factors
contributed to the record flooding in and near Carlsbad. Floodwaters
from Rocky Arroyo Draw fed into the Pecos River north of Avalon Reservoir.
This flow along with heavy rainfall from thunderstorms resulted in
a required release of water from the Avalon Reservoir. Radar estimated
rainfall totals of 3 to 4 inches fell near and west of Avalon Reservoir
between 900 PM MST on April 3rd through 100 AM MST on Sunday, April
4th. Releases from the reservoir began near 800 PM MST on April 3rd,
with a measured peak rate of 14,800 cfs (cubic-feet per second) at
around 400 AM MDT Sunday morning. This release of water eliminated
the potential danger of a dam failure, but resulted in the washout
of Callaway Drive just downstream from the release point on Avalon
Reservoir. The following pictures are of the main release point of
Avalon Reservoir and the effects of the release on Callaway Drive.
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Figure 1. Avalon Reservoir
Figure 2. Pecos River washing our Callaway Drive |
| The second factor contributing to the record flooding was extremely
high flow through the Dark Canyon Draw into downtown Carlsbad. Radar
estimated rainfall of 1 to 3 inches fell over and southwest of Dark
Canyon during the evening and overnight hours of Saturday April 3rd.
This rainfall led to catastrophic flash flooding along the Dark Canyon
Draw from southwest portions of Carlsbad into the downtown area. A
wall of water moved down Dark Canyon Draw at approximately 1:30 AM
MST Sunday morning. The pictures below show some of the effects of
the flooding. The first picture shows a water tanker that flowed down
Dark Canyon Draw, and eventually was pushed up against the Atchison
Topeka and Santa Fe Railroad Bridge just east of Highway 285 bridge.
The second picture shows the washout of Hidalgo Road at Dark Canyon
Draw. The third picture shows the washout of Boyd Drive at Dark Canyon
Draw. |
Figure 3. Dark Canyon flowing across railroad bridge. |
Figure 4. Dark Canyon Draw flowing across Hidalgo Road |
Figure 5. Dark Canyon Draw washing out Boyd Drive. |
| The third factor that contributed to the flooding was the failure
at several points of the CID (Carlsbad Irrigation District) canals.
These CID channels, used primarily to irrigate areas alfalfa fields,
began failing due to runoff from the 8-12 inches of rainfall over
the three days crossing perpendicular to the CID channels. Erosion
of the channels began occurring due to the high volume of water flowing
over them. As the channels finally failed, water flowed into adjacent
neighborhoods. The community hardest hit by this runoff was the La
Huerta neighborhood in northeastern Carlsbad. The following picture
shows the major points at which the CID canals were breached and allowed
water to flow through the La Huerta neighborhood. As a result of this
flooding, 6 to 12 inches of water was left standing throughout most
of the La Huerta area with higher amounts at isolated points. |
Figure 6. |
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weather.gov 
