FLOOD05827

• County: Boulder
• Community: Boulder
• Stream Name: Boulder Creek
• Basin: South Platte
• Title: Boulder Creek Phase B
• Date: 12/1/1979
• Prepared For: Boulder
• Prepared By: UDFCD
• Floodplain - Doc Type: Floodplain Report/Masterplan

Column 8 - Residual Average Annual Flood Damage Cost

Each of the vanous a 1 ternat i ves wi II s till incur expec ted. damages when,

for example, the lOO-year storm overflows a channel which is designed

for the 5year flow. These damages do not include channel erosion and

structural damage which are part of annual O&M.costs, but do include

residential and commercial flood-caused damages. Data on residual

average annual flood damages prepared by the Corps of Engineers (March,

1977) was updated to 1979 based on building cost indexes published in

Engineering News Record.

Column 3 - Construction Cost

Capital construction cost for each improvement action listed; developed

using the unit prices, engineering, fiscal and administrative, and

contingency costs previously presented in this section.

Column 4 - Right-of-Way Cost
The costs associated with land acquisition within the study area were

extracted from data prepared by the Corps of Engineers and were updated

to reflect current valuations.

Column 5 - Total Cost

The total cost of construction and right-of-way

Column 6 - Annualized Total Cost

The total cost amortized over a 50-year period using a 6-6/8 percent

interest rate.

Column 7 - Annual Operation and Maintenance Costs

Operation and maintenance (O&M) cost includes the daily, monthly and

yearly efforts required to maintain the hydraulic and aesthetic qual ities

of the drainageway.

These efforts would include, but would not be limited to the following

o

replacement of pedestrian bridges at 25, 50, and 75 year".

Mowi ng

access path repair

ferti 1 izing
weeding
amortization of equipment

wages and benefits of employees

reseeding of damaged areas

bank stabilization
repair of erosion damage

o

o

o

o

o

o

o

o

o

items:

o debris removal

o sediment removal

Column 9 - Average Annual Damage Reduction
The average annual damage reduction is the estimated total accrued

benefit resulting from constructed improvements. It is the difference

between the present level of expected annual damages and the annual

o

Trimming trees and brush

replacement of landscaping (trees and bushes) at 25, 50, and

75 years.

o

64

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I