AWM (automated water machines)
People will never learn to use something scarcely & reasonably, unless they start paying for it...

Solution

from the brief "Water is often wasted because it is under-priced. "

In public buildings like malls, schools, universities, hospitals etc. usually there is no control over the use of water in the sinks of the restrooms.
Most of them do have censors and/or are timed but this is not enough since most of us are never satisfied with the already programmed amount and use the sink again, waisting more water.
My proposal for a future plan for saving water would be elimination of free use of water in the sinks of the public restrooms and the restrooms of public buildings and equipping the restrooms with AWM ( automated water machines ) which would function like ATM's but would provide with water instead. The AWM device could have several buttons according to each person's need  for washing of hands, and could receive payment by cards.
However, since there will always be people who refuse to pay for the public resources, and to provide a certain level of protection against bacteria and microbes,  a free-of-charge option would also be available, a disinfectant sprinkler for hands, with sensor that   provides up to 2 psst per each person's hands.

sketches and other coming soon cos at the moment i am also working on diplom project :)