WSPC01704

• File Number: 5000.375
• Description: Flood Protection Section - Alamosa - Rio Grande Flood
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 8/8/1985
• Author: CWCB - DODES
• Title: Report on the Findings of a State Damage Survey Team on the Rio Grande Flood of June 8-14 1985 - Rio Grande and Alamosa Counties - Colorado - CWCB - DODES - Second Preliminary Draft
• Water Supply Pro - Doc Type: Report/Study

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2.1.8 Dike North of Monte Vista

Concern:

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The upper (west) end of the dike has several low points
and numerous weak points. If the upper end was to break, Monte
Vista would once again be flooded with the flood waters coming
into the Town further west of the 1985 dike failure.

Findings:

The Monte Vista levee was built on private property from
irrigation ditch waste material. Beginning at a point about 1
1/2 miles north of Monte vista on Gunbarrel Road, the levee
extends along the south bank of the Rio Grande approximately ,1
1/2 miles upstream. It has an irregular cross section and
parallels the north side of the Nichol ditch. Reshaping of the
levee at several isolated sections and for an 840 foot long
section appears to be needed, However, the upstream end of the
levee does not tie into high ground. Therefore, floods larger
than about one in 40-year event are able to flow around the
levee and into the Town of Monte Vista. To cut off this flow,
the levee would have to be extended approximately 8000 feet
upstream to the intersection of Swede Road with Stoeber Lane.

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Flooding of Monte Vista in 1985 resulted from a breach
in the levee near its downstream end. This water became
trapped behind Gunbarrel Road and spread laterally towards the
town, Tne repaired section appears to be adequate.

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Monte Vista is in the Regular
Flood Insurance Program. As of March,
policies in force in Monte Vista.

Phase of the National
1985, there were only 7

Cost Estimates:

To reshape the existing spoil bank levee at upstream end
= $ 3,697

To construct a major cutoff levee -
8,000 feet at $60/foot = $480,000

Recommendation:

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The upper end of the levee should be reshaped with a
combination of materials on site and materials hauled to the
site. This work should qualify under the state emergency
fund. A survey of the repaired levee should be made along the
crest to confirm that is is higher than a 500-year flood. The
Army Corps of Engineers should be requested to investigate the
feasibility of a major levee improvement project.

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