State laws in the United States recognize any natural body of water of 10 or more acres (40,000 square meters) as a great pond, held in trust by the state for the public's enjoyment and use. The concept, like many in American law, has its source in English common law, where navigable waters fell under the jurisdiction of the admiralty and were accessible by all for fishing, navigation, or any other use. The limit of the admiralty’s jurisdiction, though, was marked by high tide, which exempted all freshwater bodies of water. Bodies of fresh water were considered the property of those whose property bordered them, and their use was generally restricted to the landowners and their guests, denying their use to the common people.
Coming from a culture where the public could be denied the use of freshwater ponds, it was important to the egalitarian-minded Americans that such an inequity not be perpetuated in their new home. In addition, the right to hunt on public lands, and fish the public waters, guaranteed that they’d never become dependent on the Crown or any other form of nobility for their living. They developed the 10-acre (40,000-square meter) standard for freshwater ponds to define public waters, and guaranteed the public the right to use them. Great pond laws featured in the early legislation of the colonial and state legislatures; in modern times, these laws require that if a great pond is completely surrounded by private property, reasonable public access to the pond must be granted.
That a great pond’s natural surface acreage is at least 10 acres (40,000 square meters), or has demonstrably been that size in the past, is a critical nuance in great pond law. If it can be shown, for instance, that a pond that is now 11 acres (44,000 square meters) has been artificially increased in size from 7 acres (28,000 square meters), then it will lose its status as a great pond and the owner or owners of the land surrounding it can restrict access. On the other hand, a body of water that’s grown naturally to a surface area of or greater than the required surface acreage also would be considered a great pond.
An interesting aspect of the law is that the water in these types of ponds is owned and can be used by everyone. A landmark lawsuit was brought in 1890 by a mill owner who sued to prevent the taking of ice from the great pond feeding the millstream, thus reducing its flow. The court’s judgment was that the water was public property and no member of the public could be prevented from using or taking it, even if that taking affected another person’s commercial interest in the water.