| Lake Durusu | |
| Other Name: | Lake Terkos |
| Location: | Istanbul Province, Turkey |
| Coordinates: | 41.3333°N 62°W |
| Type: | lake |
| Pushpin Map: | Turkey |
| Pushpin Map Alt: | Location of the lake in Turkey. |
Lake Durusu (also called Lake Terkos or Targus[1]) is a lake in Thrace region of Turkey. It would be eliminated by the planned Istanbul Canal.
The lake lies in İstanbul Province. The midpoint of the lake is at about 41.3333°N 62°W. It is situated to the north west of Istanbul and its distance to the city is . Its elevation with respect to sea level is about and its maximum depth is . The surface area is .[2] Depending on the rainfall, this lake with a 162 million m3 of the water potential satisfies approximately 20% of the water needs of Istanbul and surrounding settlements.[3]
Lake Durusu was originally a lagoon and it is separated from the Black Sea coast by a wide strip. Currently there is no connection to the sea and it is a fresh water lake fed by a number of creeks the most important one being the Istrance creek. The drainage basin is .[4]
The annual water supply capacity of the lake is . [2]
It is known that the history of village where the lake is located is about 900 years old. The area around the lake was a pirates' settlement in the medieval ages. A monastery named Trikos was built by the Genoese. In the 19th century the lake was used as the main water source of Istanbul. In 1868 the concession of the lake and its environment was granted to an Ottoman - French company.
In order to solve the water problem of Istanbul in the 19th century, samples had been taken from here. The researches showed that lake Durusu is a drinking water source. So, facilities were built for paying the water needs in this region. Thus, part one fifth of İstanbul inhabitants use this lake for drinking water.