27 gallons of water per load of dishes? That sounds like they were washing dishes under running water which is obviously wasteful. Fill a dishpan, do the dishes, rinse them with clear water at the end and you will need very little water in total.

That may well be true, but washing in the sink uses almost no energy - to directly compare the two, you'd have to compare the energy used directly by a dishwasher and hand washing (heating the water), plus the energy required to filter the waste water from each.

I agree it obviously doesn't use much power, though in a lot of places fresh water is a much bigger concern (and that's really saying something). California comes to mind.