FLOOD04820

• County: Statewide
• Basin: Statewide
• Title: Evaluation and Implementation of Urban Drainage and Flood Control Projects Completion Report
• Date: 6/1/1974
• Prepared By: CSU Environmental Resources Center,
• Floodplain - Doc Type: Educational/Technical/Reference Information

B. Intangible Benefits

1. Reduced inconvenience.

2. Social environment benefits.

3. Sense of security benefits.

Tangible direct benefits can be quantified. This does not imply

that they are more important than intangibles or indirect benefits.

Indirect and secondary benefits are not as readily quantified as direct

benefits. See the discussion in the next chapter regarding them.

Intangible benefits cannot normally be quantified and must be handled

qualitatively. The bulk of the numerical benefits which will be included

in this example will be reduced flood damages. Values for the potential

for loss of life can also be included, see [2].

Where benefits are not presented quantitatively, they can be

included in narrative form. This applies to direct, indirect and

intangible benefits. The WRC system of aceo~ in Chapter II is

an attempt to do this. Where quantification of benefits is considered

controversial, it is recommended that the engineer prepare his benefit-

cost analysis with and without the benefits in question so that their

effect on the recommended alternative can be observed.

Engineering data are required from the hydrologic and hydraulic

analyses which include:

A. Existing and future flood hydro graphs for the range

of recurrence intervals of interest.

B. Delineation of the future floodplains on adequate topo-

graphic mapping which reflects the existing channel

situation. The assumed future development patterns

will be overlaid on these projected floodplains and

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