FLOOD11630 ‎(2)‎

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

Flood Control Systems
Fountain Creek and Tributaries Upstream of Pueblo: Other than the levees and channeliza.tion
work in Pueblo, there aze no other significant flood control systems to evaluate ailong Fountain
Creek. The creek has extensive overflow azeas between Manitou Springs (west c~f Colorado
Springs) and Pueblo. The floodplain between Colorado Springs and Pueblo consists of a narrow
agricultural sti-ip that is highly susceprible to erosion. At Manitou Springs, the encroachment of
urban development on Fountain Creek has created a serious local flood concem. Due to the lack
of any mitigating flood control systems, Manitou Springs experienced significant damage as a
result of the Apri129, 1999 flood. Somewhat similar circumstances in Coloradv Springs resulted
in two mobile home parks being flooded. The creek crested on Apri130, 1999 and reached the
confluence with the Arkansas R.iver on May 1, 1999. .
Minor tributaries in the area also inundate and erode agricultural lands and wash out key farm-to-
market roads. During this flood event several roads and bridges in Manitou Sprin.gs and
Colorado Springs were damaged. Pinon Bridge between Manitou and Colorado ~~prings lost a
central span due to scour beneath supporting ~iers. The Corps constructed a streambank
protection project to protect both bridge abutments in 1989. Since coanpletion of that project the
bridge abutments have survived floods that have now twnce undermined and destr~oyed the
central span on the bridge. The Pinon Bridge staff gauge, which is a key part of tYie Pueblo early
#lood warning and response system, was also lost.
Fountain Creek Levees and Channelization at Pueblo: The Corps constructed syst:em performed
well and prevented flooding and property damage within the project limits. The e~st flood
control levee experienced some significant loss of riprap at 13`~ Stree~ An engine~r team was
dispatched from the Albuquerque District to meet with local officials, visit the project and
recommend repairs at 13`~ Street. The City of Pueblo is the project sponsor. The ~'ueblo City
Director of Public Works submitted a request for rehabilitation of the ~orps flood control
project. Repairs are scheduled to be made under the Corps of Engineers Public Law 84-99
Emergency Levee Restoration and Repair program. Aggradation within this reach had
completely covered a grade control structure just upstream of the Missouri Pacific Railroad
bridge.
Pueblo Dam: The dam began storing all inflow on Apri129, 1999. The Corps of F;ngineers has
flood control operation responsibility on this Bureau of Reclamation p~oject and took over flood
control operations by Apri130, 1999. The dam was being operated under a deviati~n from
standard operations for about a year to accommodate work to construct a stabilizin~ berm on the
downstream toe of the darn. Under this deviation, the irrigation storag~ pool has bf.en
maintained at lower levels than usual. During the flood event, inflow was approximately 4,000
c.f.s. while the outIIow was being restricted to just 100 c.f:s. The Arkansas River flows had
crested at Pueblo and Avondale on May 1, 1999 without incident.
Pueblo Floodway and Levee Extension: The Corps constructed floodway and leve~~ extension
were subjected to non-damaging outflows from Pueblo Dam and perfoxmed without incident.
Chapter 3- Flood of Apri12~, 1999
Post Flood Assessment Report ~ 19 Drrrft Revised C19/09/99