sentences:  Alternatively, simple mud and rubble barrier check dams may be built across the contour of a slope with a high embankment on the three sides while the fourth side is left open for the rainwater to enter.These catch and conserve rainwater, leading to improved percolation and groundwater recharge.They are very common in most villages of states of Haryana, Rajasthan, Uttar Pradesh and the Thar desert of Rajasthan in India.