I have a new house with a well, septic and one bathroom hook up. When the washer drains you can hear noise coming from the toilet (which is upstairs) and when you check the water in the bowl has lowered.

How cold is it in your area? It is possible that your vents exiting the roof have frozen over(frozen shut). This would cuase gurgling in toilets and or other fixtures in the house when washer is draining. It would also explain the lower water level in toilet, because when the washer drains, it is sucking the water out of the toilet(trying to use the toilet as a vent). Let me know. I have seen more problems this year in my area with this exact thing happening than ever before. Are you noticing any sewer gas smells in the house?