The term 'OUTLET FOR SURPLUS WATER' can be summarized as an OVERFLOW, which is an eight-letter word. An OVERFLOW is a device or structure that allows excess water to be released from a reservoir or other body of water. This is often done to prevent flooding or to maintain the water level in a lake or river. Overflows are also used to divert water away from areas where it is not wanted, such as agricultural fields or urban areas.