system, scheme - a group of independent but interrelated elements comprising a unified whole; "a vast system of production and distribution and consumption keep the country going"

river - a large natural stream of water (larger than a creek); "the river was navigable for 50 miles"

facility, installation - a building or place that provides a particular service or is used for a particular industry; "the assembly plant is an enormous facility"

infrastructure, base - the stock of basic facilities and capital equipment needed for the functioning of a country or area; "the industrial base of Japan"

artificial lake, reservoir - lake used to store water for community use

water main - main (a pipe or conduit) for conveying water