I'm working on calculating my swale size using this calculator https://www.permaculturereflections.com/swale-calculator/. I'm struggling to find 100 year rainfall data for MA. Does anyone have a resource they've used in the past, I keep ending up on sites with interactive maps and charts, but this is not giving me the information that I'm looking for. What resources have you all used to gather your 100 year weather events? This is what I've found so far but it doesn't even go back 100 years, http://water.weather.gov/precip/.