FLOOD11630 ‎(2)‎

• County: Statewide
• Basin: Arkansas
• Title: Post Flood Assessment Report - Arkansas River
• Date: 9/15/1999
• Floodplain - Doc Type: Flood Documentation Report

deep across the main tourist area of Manitou Springs presents a real threat to life and properry.
As pointed out in the reconnaissance report, even the best flood warning system may not be
effective when a high percentage of the population may be tourists who are unfamiliaz with the
emergency procedures. On the other hand, a higher capacity channel would result in faster travel
of the peak flow to downstream azeas that already experience problems with flooding.
Arkansas River
Increased base flow in the Arkansas River induced by the dischazge of trans-mountain water into
Fountain Creek creates a similar imbalance in the river system. The natural processes of
meandering, increased bank erosion and channel bed degradation in some reaches arnd increased
aggradation of the channel bed in other reaches negatively affects communities aiad properties
along the river. Such effects have been evident for Rocky Ford, La Junta and Las Animas.
Discharges of water stored at Pueblo Dam might also be considered an artificially induced
increase to the base flow within the Arkansas River as well. When such releases are made in
anticipation of flood control storage requirements, there is the possibility that dov~mstream flood
conditions could be worsened. Over the past year the dam has been operated und~r a deviation
from the standard procedures to accommodate construction of a stabilizing berm an the
downstream toe. Irrigation storage levels have been maintained at lower than usu,al levels. The
Bureau of Reclamation has requested a change to the deviation allowing greater irrigation
storage. The stabilizing berm is near complete and therefore the dam safety concerns which lead
to reduced storage levels are not as compelling.
Although Trinidad Reservoir provides protection in the upper reaches of the Purgatoire River, the
flood peak at Las Animas is ~hardly affected for the lazger events. Nevertheless, f~r more
frequent events, the storage of flood volumes in the upper reaches provides some benefit to
downstream communities.
ASSISTANCE PROVIDED BY THE CORPS OF ENGINEERS
The following flood assistance authorities and programs were used during and after the Apri129,
1999 flood:
Public Law 84-99: This law authorizes the Corps of Engineers to provide emergency operations,
investigation and rehabilitation of damaged Federal and non-Federal flood control projects, and
after action reporting. The Corps executes these responsibilities under the Flood C;ontrol and
Coastal Emergencies Program financed under appropriation 96X3125. At the start of the flood
event the district had $35,000 under category 200, Emergency Operations, Class 210, Response
Operations. This amount was increased by an additional $35,000 on May 6, 1999 for a total of
$70,000. On May 11, 1999, the Albuquerque District requested Category 300, Re]Zabilitation
and Inspection Program funds, Class 340, Field Investigation for Proposed Rehabilitation
Chapter 3- Flood of Apri129, 1999
Post Flood Assessment Report ~~ 29 Draft Revised 09/09/99