For the 1,100 villagers of Kamanayakanahalli in Bagur-Navile hobli of Channarayapatna taluk, the imminent extinction of a century-old tank reminds them of what the construction of one of the longest irrigation tunnels in the country did to a large area.While the villagers in the Bagur-Navile region are facing problems owing to the depletion in the groundwater level because of the tunnel, those of Kamanayakanahalli are a worried lot as the tank is on the verge of extinction thanks to the sub-channel that had been dug to provide water to 5,800 acres of land from the Navile Lift Irrigation Scheme (NLIS). The sub-channel begins at Navile village, passes through Ramapura and Chikkonahalli cutting across Kamanayakanahalli before reaching Santheshivara tank.