Section 90-147. Rainfall intensity.
In determining peak stormwater discharge rates, intensity of rainfall values shall be obtained through a statistical analysis of historical longterm rainfall data or from sources or methods generally accepted as good engineering practice. Examples of acceptable sources include the following:
(1) USDA Soil Conservation Service, Rainfall Frequency Atlas of Alabama, Florida, Georgia, and South Carolina for Duration from 30 Minutes to 24 Hours and Return periods from 1 to 100 Years, January 1978, Gainesville, Florida.
(2) U.S. Weather Bureau technical paper no. 49.
(3) U.S. Weather Bureau technical paper no. 40.