Archimedes Screw - Ability to Move/Pump Water up a slope.
There have been many chats about water pipes and aqueducts, but would be great to see this coupled with a mechanical pump that moves water at an angle. Screws could be 'chained' together for higher elevation. The longer the screw, the more power consumed. Could be paired with intermittent power (such as wind mill). Could be paired with a reservoir to store water in the drought. Could run backwards for a reduced power output, like dam power storage/output.