WSP05149

• File Number: 8180.800
• Description: Purgatoire River Project
• Basin: Arkansas
• Water Division: 2
• Date: 9/1/1949
• Author: RJ Tipton
• Title: Engineering Report on Flood Control and Irrigation District with Particular Reference to the Piedmont Bridge Dam and Reservoir Site
• Water Supply Pro - Doc Type: Report/Study

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(a) Hydroelectric power
(b) Fish and Wildlife
(c) Recreation
(d) Domestic water supply

PIEDMQNT BRIDGE RESERVOIR
Cost and Allocation of Capacity. Using the general design
of the Corps of Engineers, costs of the dam and reservoir were
estim!j.ted be.sed on 1946 and present-day prices. The bstlmated con-
struction cost 'W8S $10,810,000 for 1946 and $14,472,000 for the
present time, both estimates including 35 percent for engineering

and contingencies.
Several methods may be used to allocate the capacities of a
reservoir to various functions. The most rational is considered

to be the use-of-facilities method which was used. Of the total

designed capacity of 81,500 acre-feet, 27,500 acre-feet would be

required for flood control. This would leave 54,000 acre-feet

of capacity for the regulation of irrigation water at the begin-

ning of a 50-year amortization pel'iod.

It is estimated, as d::~s-
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cussed in the following section, that at the end of 50 years

30,500 acre-feet of silt would have been deposited in the reser-

voir. Assuming that the flood control capacity is kept intact

during the amortization periOd, the amount of storage capacity
remaining in the reservoir at the end of the period for the regu-

lation of irrigation water would be 23,500 acre-feet. The average

amount of capacity utilized for irrigation during the amortiza-

tion period therefore would be 38,750 acre-feet. The operation

studies indicate that all of the capacity remaining over and

above that allocated to flood control and that occupied by

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