FLOOD06619

• County: Statewide
• Community: State of Colorado
• Basin: Statewide
• Title: Federal Guidelines for Selecting and Accommodating Inflow Design Floods for Dams
• Date: 2/1/1986
• Prepared For: State of Colorado
• Prepared By: FEMA
• Floodplain - Doc Type: Project

the downstream inundation would be essentially the same with or

without failure of the dam. The consequences of dam failure would

not be acceptable if the hazard to these habitations was increased

appreciably by the failure flood wave or level of inundation, e.g.,

the case where failure of a storage reservoir would add appreciably

to the outflow hydrograph.

In addition to the conditions listed in section F.1.c., the selected
magnitude of the IDF should be based on the following special consid-
erations:

. Dams which provide vital community services such as municipal
water supply or energy may require a high degree of protection
against failure to ensure those services are continued during and
following extreme flood conditions when alternate services are
unav a il ab 1 e ,

. Dams should be designed to not less than some minimum standard

to reduce the risk of loss of benefits during the life of the

project; to hold O&Mcosts to a reasonable level; to maintain

public confidence in agencies responsible for dam design, con-

struction, and operation; and to be in compliance with local,

State, or other regulations applicable to the facility.

G. Guidelines for Accommodatinq IDFs

L General Considerations

The IDF may be accommodated by spillway and outlet works discharge capacity,

reservoir storage, or a combination of these means, Determining the

appropriate balance of spillway discharge capacity and reservoir storage

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