FLOOD02638

• County: Montrose
• Community: Montrose
• Stream Name: Uncompahgre River
• Basin: Gunnison
• Title: Montrose Flood Control and Drainage Plan
• Date: 3/1/1981
• Prepared For: Montrose
• Prepared By: Gingery Associates, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

of SO years. The cost of upgrading the cxistinr, system in order to .last
SO years would not be encountered if the proposed Flood Control Plan
was constructed. This savings is the advanced replacement benefit.
For Montrose Arroyo, the total average annual damages (area under

the damage - frequency curve) are $198,000 and the residual damages are

$15,000. This yields a difference, or reduction in damages for the project

of $183,000. Adding approximately one percent of the estimated construction

cost for employment benefits, or $23,000, and $4,670 for annual advanced

replacement benefits, the total average annual benefit is $210,670.

For Cedar Creek, the average annual damages are $24,000 and the

residual damages are $3,500. The reduction in damages is a differen'ce

of $20,,500. Adding employment benefits of approximately one percent of

project construction costs, or $880, and $220 for annual adv'-U1ced replacement

benefits, the total average annual benefit amounts to $21,600.

Average Annual Project Costs
Average annual costs include amortization of construction costs for

construction of the project plus applic:able operation and maintenance

costs. Amortization of capital costs for construction on an equal

installment basis is a function of two varia,bles: project life and

the interest rate. The useful life for flood control proj ects is typically

50 years.

The interest rate is a function of the source of money. In the private

sector, the interest rate ca.n vary considerably and will probably not be below

ten percent. A loan from the Federal Government, such as Farmers Home

Administration, may be as 10w as five percent.

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