water supply

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The water available for a community or region.
• noun The source and delivery system of such water.

from the GNU version of the Collaborative International Dictionary of English.

• A supply of water; specifically, water collected, as in reservoirs, and conveyed, as by pipes, for use in a city, mill, or the like.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a facility that provides a source of water