Atlas 14 IDF regionalization
To assist in using Atlas 14 data with the Rational Method, MnDOT has created 32 Atlas 14 Rainfall Intensity-Duration-Frequency regions. These regions supersede the 3 regions specified in the drainage manual. These tables were designed to be used with the Rational Method which is typically used for storm drain design and catch basin spacing.
Click on a region of the map to locate IDF link or view/print list of Minnesota counties with assigned Atlas 14 regions (PDF 0.5 MB). View Atlas 14 regionalization documentation (PDF 0.5 MB).