Legal action for denial of Drinking water

Hi, My parents are senior citizens, doing agriculture and staying in a village in western ghat. My father's elder brother had cut the DRINKING WATER & irrigation pipe lines connected to a natural lake saying that the LAND where pipes are put is in his name. He also told that if you allow me to make a road upon your land then only we give water. We gave complaint to Police and Tahsildar on 11-Jan-18 attaching the partition deed which clearly says that water should be shared after the partition as it was earlier. There is no alternative source for water. We and other our neighbors are depending upon this lake water since centuries and the pipe lines were put several decades ago. It is shown on village map as well. When we spoke to Tahsildar he said if you allow road to them they will give water! Till now he has not taken any action. My lawyer said as it is a Revenue matter we cant approach civil court directly. We are clueless now and not sure about the way forward. Pls guide me.