rain

nearby water body

public water supply by govt

well

either 1 or  2 or all are  available

well or storage tank is constructed to a considerable depth

well consist of a concave disc attached to spring

spring is such  that it gets compressed by weight of water above it+ weight of disc

disc has one way valve so t water goes only up and no back flow of water occurs

A another tank is present in middle of farm constructed to  a considerable depth 

water from big storage tank or well flow to it by means of gravity again by gravity water can reach the crops present in farm by means of pipe with valves for dripping action