Bagur Navile Tunnel is the longest water tunnel in india, constructed between 1979 and 1990 is located between bagur and navile village of Chennarayapatna taluk of Hassan district, Karnataka.
Length
Length of the tunnel is 9.7 km,75 to 200feet Deep under the ground.Water is supplied from Hemavathy basin to Shimshabasin using this tunnel.Estimated cost of this tunnel is 50Crore.
References
Bagur Navile Tunnel Wikipedia(Text) CC BY-SA