FLOOD06381

• County: Otero
• Community: La Junta
• Stream Name: Arkansas River & Tributaries
• Basin: Arkansas
• Title: La Junta, Colorado Local Protection Project Phase I GDM Sediment Investigation
• Date: 9/1/1985
• Prepared For: US Army Corps of Engineers
• Prepared By: The Hydrologic Engineering Center
• Floodplain - Doc Type: Project

Table 5.1

HEC-6 Single-Event Results

Arkansas River at La Junta, Colorado

5O-Year Flood
E.isting Project '3 Project '4
A Bed~ A Bed 2 y' y4 A Bed A Bed Y Y ABed ABed Y Y
Sect ion Peak End ma. max Peak End ma. ma. Peak End ma. ma.
NlJ1t>er (ft) (ft) (ft/s) (ft) (ft) (ft) (ft/s) (ft) (ft) (ft) (ft/s) (ft)
1194.2 0.0 -0.1 4.6 5.1 0.0 -0.1 4.6 5.1 0.0 -0.1 4.6 5.1
1194.9 ..0.1 +0.2 3.5 5.0 ..0.1 +0.2 3.5 5.0 +0.1 +0.2 3.5 5.0
1195.6 +0.1 +0.1 3.7 4.7 +0.1 +0.1 3.7 4.8 +0.1 +0.1 3.7 4.8
1196.3 -0.2 -0.4 4.3 3.0 -0.1 -0.3 4.3 2.9 -0.1 0.2 4.3 3.0
1196.5 -0.1 -0.3 3.0 3.6 +0.1 0.0 3.0 3.5 +0.1 +0.1 3.0 3.5
1196.7 +0.1 +0.2 2.6 4.7 +1.4 +1.9 3.1 3.9 +1.8 +2.6 3.2 3.7
1196.9 -0.1 -0.1 4.1 3.6 ..0.7 +1.4 4.5 3.8 +0.0 +1.3 4.1 4.2
1197.2 0.0 0.0 3.3 4.7 -0.8 -0.1 6.7 6.6 -1.1 -0.6 8.9 6.4
1197.7 0.0 ..0.1 3.3 4.2 -0.6 -0.7 6.6 9.0 -0.9 -1.1 8.5 11.5
1197.9 +0.1 ..0.3 3.2 4.4 -0.9 -1.1 6.5 9.2 -0.8 -1.2 7.2 12.2
1198.1 +0.1 ..0.3 3.5 4.2 -1.0 -0.9 6.9 9.5 -0.9 -0.9 6.8 12.0
1198.4 +0.1 ..0.2 4.5 4.0 -0.9 -0.6 5.1 11.4 +0.2 +0.2 4.8 12.3
1198.8 +0.2 ..0.3 3.5 6.0 -1.4 -1.0 7.1 9.5 -0.8 -0.8 6.7 10.2
1198.9 0.0 +0.2 5.2 6.4 -1.2 -0.5 4.3 9.4 -0.3 -0.4 5.3 10.3
1199.2 +0.3 +0.7 3.6 6.4 +1.7 +1.6 3.8 8.4 +2.2 +1.5 4.6 8.8
1199.3 +1.3 +1.2 4.9 5.6 +1.4 ..0.7 5.1 8.2 -0.2 -0.5 6.1 10.0
1199.5 -0.3 -0.3 3.5 4.1 -0.3 -0.4 4.2 6.7 -0.9 -1.4 5.5 8.5
1199.7 -0.3 -0.5 5.2 4.9 +0.1 -0.4 4.8 5.7 +0.5 -0.4 4.7 8.0
1200.1 0.0 0.0 4.0 6.0 +0.8 +0.8 4.5 5.9 +0.4 +0.1 5.8 7.1
1200.5 +0.3 +0.3 4.5 5.1 +0.4 +0.1 5.2 5.9 0.0 -0.3 5.6 8.0
1201.0 +1.2 +2.5 4.9 5.6 +0.6 +2.7 6.7 8.4 +0.8 +2.7 6.4 8.6

~ Change in bed elevation from initial bed at peak flow.

2 Change in bed elevation from initial bed at end of flood event.

· Ma.imum mean flow velocity at section.

4 Ma.imum water depth at section.

63