From Time - CNN

The headline below asks if we are dependent on water to survive. Water in Kentucky is not the issue ; the issue here is the ability to get the water to our home.
The article from Time - CNN above shows and talks about low water at Lake Mead - one of California's sources of water.
Water in the ocean can be cleared of it's salts and used by the city but the city would have to have a high pressure "Reverse Osmosis Filter System" to use water for general use.
The water from the mountains is filtered naturally and is almost ready for use.