Rainwater disposal Home › Forums › Archives › Old Bulletin Board Archives › Rainwater disposal This topic has 0 replies, 1 voice, and was last updated 27 years, 3 months ago by Michael Verdello. Viewing 0 reply threads Author Posts 7 Oct 1997 at 5:55 pm #282014 Michael Verdello Has any one ever designed software to make working out of drain sizes either using the Manning or Colebrook-White formulas? Author Posts Viewing 0 reply threads The forum ‘Old Bulletin Board Archives’ is closed to new topics and replies.