The tunnel was commissioned by the Ministry of Forest and Water Management and constructed by an international consortium of Russian and Turkish companies (Mosmetrostroy, ALKE and STFA).
The Melen Water Supply Project was funded mainly by JBIC (Japanese Bank for International Cooperation) and partly by DSI (State Hydraulic Works).
The TBM-drilling part of the project was completed in May 2009 and a ceremony was held, with the attendance of minister Prof. Dr. Veysel Eroğlu, bureaucrats, Russian diplomats and Kadir Topbaş, the mayor of Istanbul.
Situated between Ortaçeşme (Beykoz) and Derbent (Sarıyer) under the Bosphorus, the 5,551 m (3.449 mi) long waterway tunnel has a water flow rate of 32.5 m3/s (1,150 cu ft/s).
[1] Being the first stage of the Melen System that cost 2 billion TL, the waterway tunnel was constructed in 1,756 days and completed on 19 May 2012 without any accident.