The pictures at the following show the flooding from last April.

http://www.flickr.com/photos/22343195@N00/sets/72157627610741499/

This situation arises during abnormally heavy rain events and during the spring thaw. My property is at the edge of this body of water with the main part falling on my neighbor's property. She does not get water in the basement while I do, but only from the wall facing her property. However, the sump does become overwhelmed by the amount of ground water that occurs during these heavy rain events.

I'm interested in creating a passive system that will take the pressure and dependence off of the sump pump. While I do have a battery backup there is no way the pump would be able to keep up if the power should go out. I'm not sure where this body of water could be drained to, as our properties are quite flat and are at the bottom of a hill. Any suggestions?