Or you can eliminate the head by using a composting toilet, or for a long term scenario build an outhouse. I went with a composting toilet, so my septic tank shouldn't need to be pumped out for years since it only receives grey water. I do have an outhouse as a backup, but I don't like using it in the winter. Save your water for more important needs, rather than flushing.... oh yeah, there's always the water conservation saying, "If it's yellow let it mellow, and if it's brown, flush it down."