Our solar house was earth-insulated on the back side, too.
What did you specify for uphill drainage?
There are ditches between the uphill and the house...all drains away very well. It is all insulated-concrete-formed, 8" concrete walls with in-floor ground-loop geothermal heating. The propane tank feeds the oven and clothes dryer only. There is a second building, similar construction that is a wood shop and summer kitchen for processing vegetables and making beer.