A topic recently came up in our group regarding Mottling (Seasonal High Water Table) and should it be given a listing as a restrictive boundary. My argument is that if you can head off the ground water to an area with a curtain drain or equivelant and the soils allow water to percolate downwards, it does not need to be looked at as seasonal high water. I understand that the Mottling would still be present, but that you can increase the depth of your soils by using this method. This revolves around septic systems and the need for 48" of usable soil. Any input in this matter would be appreciated.