Laavu, a traditional Finnish shelter any passerby may use. Will build my own one day. We have used the American version in the Cascades while snowmobiling . They are usually found stocked with basic supplies for a few days survival if needed.
I like the idea of a water wheel recirculating water to and from the creek to produce power when solar is not producing: Water wheel producing 24 kw power/day on 20 cm of running water (pending the building site can accommodate this