Utah Admin. Code 655-11-4F
The State Engineer may, at his discretion, accept an IDF less than the SEF based on the results of an Incremental Damage Assessment (IDA) which shows that failure of the dam would cause insignificant incremental damage to property and no additional threat to human life. The State Engineer may consider the use of early warning systems in evaluating the threat to human life. In requesting the acceptance of an IDF determined from an IDA, documentation must be furnished that the owner of the dam is aware that the design reflects something less than the SEF and they are willing to accept the additional liability. In no case will the State Engineer approve an IDF generated by something less than the applicable 100 year flood event. The resulting selected IDF, based on the IDA, should be reported as a percent of the SEF.
Utah Admin. Code R655-11-4F