ABSTRACT
In addition to being most crowded city of Turkey, Istanbul is also among the world’s most populous cities and its population is increasing day by day so that water resources of this metropolitan are under excessive stress. Today, this huge metropolitan area needs approximately 2.250.000 m3 water per day. Considerable amount of this demand -almost all-is supplied from dams around the city. Darlık Reservoir, in the North-East of Istanbul (Fig. 1), supplies the 12% of this demand, has 207 km2 catchment area is one of the important reservoirs of this city.
