WSP08574

• File Number: 8141.100
• Description: Fryingpan-Arkansas Project - Project Description
• State: CO
• Basin: Arkansas
• Date: 1/1/1969
• Author: US DoI BoR
• Title: Flood Control Fryingpan-Arkansas Project Eastern Slope Features
• Water Supply Pro - Doc Type: Project Overview

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95. REDUCTION OF OPERATING COST OF EXISTING FLOOD CONTROL WORKS.-
As previously stated, the city of Pueblo presently is provided protec-
tion from Arkansas River floods by Barrier Dam and Pueblo Floodway
completed in 1925. It is estimated that under existing conditions,
the effective life of these structures will expire in the year 2000.
Although Pueblo Dam and Reservoir would supplant the need for this proj-
ect for protection of the city from Arkansas River floods, the floodway
unit must be retained to contain residual floodflows, primarily from
Dry Creek. The capacity of the floodway is 110,000 c.f.s., but with
Arkansas River flows controlled by Pueblo Dam, a floodway of about
50,000 c.f.s. would suffice to control floods originating downstream
from the structure. Based on the lesser capacity needed and less
frequent flood discharges, it is estimated that the economic life of
the structure, which would cost about $4,000,000 to replace without
Pueblo Dam, would be extended about 25 years at which time it could
be replaced for about $2,000,000. The lower cost structure then would
be effective until expiration in 2070 of the 100-year life of the new
,..reservoir. At this point it would be replaced with another $4,000,000
structure. The replacement of Barrier Dam would also be deferred but
to the end of the economic life of Pueblo Reservoir. The estimated
replacement cost of Barrier Dam is $10,000,000. The economic value of
savings from deferred replacement reduced to an average annual equiv-
..alent basis at a 3.125 percent discount rate would be about $167,000.
In addition, annual maintenance costs of the floodway and Barrier Dam
would be reduced $60,000 by the new structure. 'As indicated above,
the Pueblo Floodway will continue to function after construction of
Pueblo Dam, but Barrier Dam will be removed. There is approximately
35 years of remaining effective life after 1970 in the structures.
The value of the remaining useful life of the existing dam is esti-
mated to be $4,000,000 or $131,000 annually. Accordingly, Pueblo Dam
and Reservoir has been credited average annual benefits of $96,000
for reduction of operation, maintenance, and replacement costs of
existing flood control works excluding the value of remaining useful
life as shown in the following table 13.

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