Fill in blank 47 with the most appropriate word.

We need to drain out water that is not used, which is excess. So, option 2 is correct. Constant electricity fluctuation and irregular power availability for irrigation are daily problems faced by many farmers for a long time. If one travels through the southern districts of Tamil Nadu, especially during the early morning or late night hours, one can see farmers sitting next to their motor pumps waiting for electricity, to irrigate their crops. Though many farmers use diesel operated pumps, a suitable alternative , which requires neither diesel nor electricity and yet meets their irrigation requirements, may be welcome. The farmer grows paddy in his one acre and to meet his irrigation needs, he used to laboriously collect overflowing water from nearby fields and well using a bowl like structure made of discarded tyre tubes. As this work proved cumbersome and required additional labour to lift and pour the water into the fields, he decided to build a hand operated water-lifting device to irrigate the field from a canal or pond and drain out excess water from cultivated land.