Where does water come from?

This overview explains the basic parts of a water system:

  • Source
  • Treatment
  • Distribution
  • Collection
  • Sewage
  • Treatment
  • Reuse

Diagram of where water comes from

  1. Water is taken from its source, which may be a reservoir (1a), river, or well (1b). Water is pumped or flows by gravity to the treatment plant.
  2. At the treatment plant, impurities in the water are removed or inactivated and depending on the plant, fluoride may be added.
  3. Clean drinking water is stored in an elevated tank.
  4. Distribution mains carry water from the treatment plant or tank to service lines. Mains also provide water to hydrants for fire protection.
  5. Service lines connect distribution mains to building and plumbing systems.
  6. Used water from sanitary sewers is piped to the sewage treatment plant.
  7. At the sewage treatment plant, used water goes through a multiple step cleansing process.
  8. Cleaned water is returned to the river where it re-enters the water cycle or is additionally cleaned and reused for irrigation purposes, such as golf course watering.