The term 'SMALL DAM' can be solved by the four letter word 'WEIR'. A WEIR is a type of small dam that is used to control the flow of water. It is typically made of concrete or stone and is designed to raise the water level, redirect the flow of water, or both. Weirs are commonly used in rivers, streams, and other bodies of water to regulate the flow of water for irrigation, flood control, and other purposes.