WSP05425

• File Number: 8101
• Description: Arkansas River Basin Description
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 9/1/1962
• Author: High Plains SCD
• Title: Watershed Work Plan - Limon Watershed Protection Project - Elbert and Lincoln Counties - Colorado
• Water Supply Pro - Doc Type: Report/Study

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C~1762

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PROJECT BENEFITS

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Flood damage reduction is the primary purpose of this project,
The estimated average annual floodwater, sediment and indirect
damage in the watershed amounts to $25,666 (Table 5).

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Land treatment measures to be installed will reduce these
damages to $24,132, or a reduction of about 6,0 percent, The
flcodwater-retarding structures will further reduce the remaining
damage to $123 or a further reduction of about 93 percent,

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Remaining flooding of floodplain lands in the overflow area
will be reduced to that caused by local runoff which cannot be
removed by city streets and storm sewers at a rate equivalent to
the estimated 100-year storm event peak rate of runoff,

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With the project installed, the areas where this temporary
backwater flooding occurs are primarily municipal, carrmercial,
and residential in nature, The principal costs will be the clean-
up of sediment and debris from streets, and lawn areas; and same
buildings may be vulnerable to a small amount of floodwater damage
from this type of flooding.

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Annual flood prevention benefits accruing to the floodwater-
retarding structures are $24,009, Possible benefits for the reduced
costs of culverts in this watershed for Interstate Highway 70 were
not evaluated,

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Benefits of an intangible or secondary nature will also accrue
to the project, A high level of flood protection to human life and
property has a value to the individual and to this community which
cannot be measured.

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COMPARISON OF BENEFITS AND COSTS

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The total estimated installation costs for the floodwater-
retarding structures are $209,544, This cost when amortized over
a fifty-year period at 2 5/8 percent interest results in an annual
equivalent cost of $7,572. The average annual cost of operation
and maintenance is estimated to be $1,077, making a total average
annual cost of $8,649 (Table 4).

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