i Almost all the houses in these regions had traditional underground tank or ‘tankas’ for storing drinking water. ( Define the term Tanka) ii The tanks could be as large as a big room. iii The tanks were part of the well-developed roof top rainwater harvesting system and were built inside the main house or courtyard. They were connected to the slopping roofs of the houses through a pipe. iv The rainwater, falling on the roof would travel down through the pipe and is stored in the underground tanks.