FLOOD03000

• County: Statewide
• Stream Name: South Platte
• Basin: South Platte
• Title: Water and Related Land Resources Management Study Volume V - Appendix H
• Date: 7/14/1980
• Prepared For: South Platte and Tributaries
• Prepared By: CWCB
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

.

Because the emergency measures are an adaptation of the

selected plan for modifications to Kelly Road Dam, the costs of

these completed measures are included in the costs of the

selected plan for economic evaluation. The costs of the emer-

gency measures are not, however, included in the "first cost to

the United States" in the Recommendations section of this report

because the implementation of these measures is already

completed.

Construction of Upper Lowry Dam. Upper Lowry Dam would be

constructed to full site capacity and would store the standard

project flood. It would have a 50-foot-wide ungated concrete

spillway that would safely pass the probable maximum flood with

3.2 feet of freeboard. The embankment would be about 9,200 feet

long with a maximum height of 45 feet. The dam would have a

l5-foot top width with 1 vertical to 3 horizontal slopes for the

top 25 feet and 1 vertical to 5 horizontal slopes from that point

down to the existing ground. A gated outlet works, 36 inches in

diameter, would empty into an existing 48-inch storm sewer which

outlets into Kelly Road Dam. Pertinent data for the dam are

presented in table 2.

;
..~

COMPONENTS WHICH ARE NOT PART OF FEDERAL ACTION BUT REQUIRED OF
NON-FEDERAL INTERESTS IN CONJUNCTION WITH FEDERAL ACTION

There are four components in this category - emergency evacua-

tion, flood plain regulations, downstream channel improvements,

and drainage channel improvements into Upper Lowry Dam.

Emergency Evacuation Downstream from Kelly Road Dam. There

would still be a substantial residual flood hazard downstream

from Kelly Road Dam, even with additional storage upstream and

31

.