High Quality Content by WIKIPEDIA articles! The Quabbin Valley is a region of Massachusetts, United States. The region consists of areas drained by the Quabbin Reservoir and accompanying river systems in Franklin, Hampden, Hampshire, and Worcester counties. The area is sometimes known as the Swift River Valley region, a reference to the Swift River, which was dammed to form the reservoir. Many people living in towns such as enfield protested that it was not fair to be destroying their town. they fought hard but what has become is history.