Privatize all water supplies.  Let the free market work.  This will make water reflect its true cost, rather than the government monopoly, taxpayer subsidized prices that may make users happy, but do not penalize them for wasting water.  The real price will encourage people to conserve and recycle water, as well as encourage businesses to find or produce water, and water saving techniques for sale.    

This means that water is a commodity, owned by private owners, not the government.  It does not mean that private businesses operate the water services, but the government has a commission that over views the company (i.e., a Corporation Commission).  Businesses cannot operate under political influence, they must operate under market influence, which includes keeping their customers happy. 

Further, government must not be allowed to monopolize water services.  While nature has a major role to play in the abundance of water, government monopolizing water leads to water as a resource being undervalued, since taxpayers subsidize the costs.  This means businesses are less willing to provide water, because they cannot compete with government, or government outright prohibits private business competition with government. 

Water is a precious commodity, but it is not limited in supply [a PDF file], it is abundant throughout the planet.  It is drink water is currently limited in supply.  Allow the free market to participate without government, and you will have all the water you desire, at its fair market value.  Because clever people always find a way, if they have the economic incentive, and other clever people will find ways to make that water last if they have the economic incentive.  And because they all compete for your dollar, they force the price of their service down competing with each other for your purchase.  Which means the supply is there, and at its market value.