Chennai has fresh water reservoirs/lakes namely Poondi, Sholavaram, Red Hills, Chembarambakkam, Veeranam to cater the daily needs of water for chennai area.

Chennai receives most of its water from
  Poondi Lake (3,231 Mcft)
  Sholavaram Lake (881 Mcft)
  Red Hills Lake (3,300 Mcft)
  Chembarambakkam Lake (3,645 Mcft).

  The Veeranam Water Supply Project was implemented as additional source of water to Chennai City. The Project was commissioned in the year 2004 to supply 180 MLD of water to Chennai City by drawing water from Veeranam Lake. This lake receives water from Cauvery River system through Kollidam, Lower Anicut and Vadavar Canal besides rainwater from its own catchment area. The capacity of the lake is 1465 Mcft. The lake water is treated at Vadakuthu Water Treatment Plant by pumping raw water at a distance of 20 km. from Sethiathope to Vadakuthu through a 1775 mm dia mild steel pipe. The treated water is then pumped at a distance of 8 km. to Break Pressure Tank at Kadampuliyur through a 1750 mm dia mild steel pipe and from there the water is conveyed to a distance of about 200 km. through the mild steel pipe of 1875 mm and 1500 mm dia by gravity to Porur Water Distribution Station near Chennai. From this Distribution Station, water is pumped to a distance of 1.2 km. and distributed to Chennai City through Trunk mains and Water Distribution stations.