Section 501.390  25-Year, 24-Hour Precipitation Event

The maximum 24-hour precipitation event with a probable recurrence interval of once in 25 years, as defined by NOAA Atlas 14; Precipitation Frequency Atlas of the United States, incorporated by reference in Section 501.200. 

(Source:  Added at 38 Ill. Reg. 17661, effective August 11, 2014)