Rainfall instensity table for PA

[Yakman256]

Hey Guys,

Hopefully an easy question for someone out there that does work in Pennsylvania. I'm looking for a table of rainfall intensities for use with the Rational Method. I have a copy of Publication 584 which provides the actual IDF curves but not the data used to make the curve. The reason I ask is that I submitted some drainage calculations to PennDOT for review and apparently I interpolated incorrectly off the chart and was off 0.1 in/hr. In order to avoid this comment in future, I was hoping someone had a resource that provided a table of the rainfall intensities that was used to develop the IDF curves in publication 584. I guess an alternative would be to make sure I use a higher rainfall intensity than I interpolated just to be on the safe side.

Any help would be appreciated.

Thanks in advance

Yakman

 

[beej67]

Well, it's complicated.

Most regulators want you to use tables they supply, usually in a drainage manual. Some have started switching over to using NOAA data, which can be grabbed at a much finer grain than state wide here:

https://hdsc.nws.noaa.gov/hdsc/pfds/

Don't forget to convert rainfalls to intensities by dividing by duration.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com