Section 105.98. Design flood criteria

The discharge capacity or storage capacity, or both, must be capable of safely accommodating the recommended design flood for the dam as classified under § 105.91 (relating to classification of dams and reservoirs). The design flood must be determined by an incremental dam breach analysis. The minimum required design storm duration is 24 hours. When considered appropriate by the Department, engineering judgment may be used to determine the design flood within the design flood range indicated below for dams of Hazard Potential Category 3 or 4. The classification or damage, or both, resulting from dam failure will determine the design flood within the design flood range.

Classification	Design Flood Range
A-3, B-3	1/2 PMF to PMF
A-4, B-4, C-3	100 year to 1/2 PMF
C-4	50 year to 100 year frequency

The provisions of this § 105.98 adopted September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843; amended January 7, 2011, effective January 8, 2011, 41 Pa.B. 219. Immediately preceding text appears at serial pages (207722) to (207723).

Notation

Authority

The provisions of this § 105.98 amended under section 5 of the Dam Safety and Encroachments Act (32 P. S. § 693.5).

Cross References

This section cited in 25 Pa. Code § 105.94 (relating to spillways).