I think this guy has the right idea. about Geo-Solar Energy systems:
Depth to Ground Water/Elevation of Water Tables in Toronto area:
This information is so far hard to find, but the below links might be a start...
I need this info to consider the thermal conductivity of the earth below and around the house. This also has important implications for thermal energy storage in the ground. A High Water table will mean foundation structural design will be affected and heat lost form the basement may be high due to the flow and thermal characteristics of groundwater.