Canal de Isabel II (CYII) is the public company that manages the water supplies for Madrid, Spain. It is owned by the Autonomous Community of Madrid.
The Y in the abbreviation is from the old spelling Ysabel.
The Autonomous Community of Madrid caters for 6.5 million people and, to do this, it operates, via Canal de Isabel II Gestión S.A., 14 dams; 75 underground water intakes; 13 drinking water treatment plants; 29 major and 285 minor regulating reservoirs; 17,163 kilometers of adduction and distribution network; 159 drinking water pumping stations and 125 sewage pumping stations; 11,148 kilometers of sewage network; 63 storm tanks; 751 kilometers of main sewers and outfalls; 156 wastewater treatment plants; and 347 kilometers network of reclaimed water.