STFA completes Bosphorus water tunnel
22 June 2012Turkish group STFA has announced the construction of a water supply tunnel underneath the Bosphorus strait, which spans the Bosporus linking Asia to Europe.The tunnel will be operational next month.
At its deepest point, the tunnel runs 135m below the sea strait's water level. Engineering the tunnel posed many technical challenges; the water is up to 70m deep, overlying a 70m thick layer of alluvium.
The tunnel is part of the USD 120M Melen Project.
The tunnel will supply the European part of the city with about three billion litres of water per day until 2040. Water is abstracted from the Melen River, stored in a holding reservoir and then fed through 170km of pipeline to the banks of the Bosphorus, where it is treated before passing through the 5.5km long tunnel. It was drilled in 1,200 days with the Herrenknecht S-391 TBM.
