Answer : 1. "Tankas"
Explanation :

Khadin-It is a temporary pond made of earth, it is built under some sloping land. There is an earthen wall (Dhora) on both sides and a strong wall made of stone on the third side. When there is excess water, the pond gets filled and the water flows into the next pond. After the water in Khadin dries up, agriculture is done in it.

2. Pond- In Rajasthan, rain water is often collected in ponds. There are separate bathing ghats for men and women here. There is a well at the bottom of the pond, which is called Beri. This ancient method of water harvesting still holds its importance. This increases the ground water level.

4. Stepwell-Stepwells have their own place in Rajasthan. This is an ancient method of storing water. It is deep and has stairs and platforms to descend and is rich in artefacts.

5. Tanka: Tanka is an underground reservoir built to store rain water. The tanka usually has a square or rectangular shape and is constructed from clay or stone. A wall is built around the tanka so that rain water can collect in it.