Definitely one of the best ways to lessen the demand for water is to begin water-conservation measures. There are many things people can do to save water without having to sacrifice much. It's all a matter of educating the public and changing habits.
Water conservation does work.
Once people learn how to conserve water, they might keep on doing it. It might become a permanent habit. For your citizens to use conservation measures, they must first learn about them. This educational process might take some money. Printing pamphlets or buying ad time on the radio would be one example of a cost to you.