There are local/regional requirements that may be more applicable, but it is not apparent how local/regional requirements could be included in this credit. For example, in my project area the 90% exceedance interval is used as a measure for fully capturing or infilltration of runoff. The 90% exceedance interval rainfall is provided by the local agency. Doing the statistical analysis for this pilot credit is not difficult. Unfortunately, the source links listed in the EPA "Technical Guidance on Implementing the Stormwater Runoff Requirements for Federal Projects under Section 438" are no longer applicable, so finding the data can be challenging.