Perhaps the best way to think about the future of water law in New Hampshire and the allocation of New Hampshire’s water resources is to understand from an historical perspective how water law in the United States developed and why it happened as it did. It would then be useful to think about how those traditional systems have served the needs of particular regions over time, and what lessons New Hampshire can draw from those experiences.
There are two main types of water allocation systems in the United States: Riparian and Prior Appropriation. Riparian water law is largely a creature of the eastern United States, and is really a "reasonable use" doctrine that developed in states where there was an abundant supply of water. By contrast, prior appropriation developed in the western United States in the mid-to-late 1800’s. Originally, prior appropriation water law was born from experiences in the western mining camps and, to a lesser extent, western ranches. The purpose behind the prior appropriation system was to give people that first put water in arid areas toward a beneficial use the right to continue to use that water to the exclusion of others. It’s a "first in time, first in right" system. Such a system was necessary where the resource was scarce and economic growth was entirely dependent on access to the water.
Both of these water allocation systems developed at a time when water consumption happened in close proximity to when the water was withdrawn. However, over time, this changed.
Developing urban centers began to reach out geographically to locate the water they needed to survive. For example, the City of New York depends on up-State reservoirs to supply its needs. Phoenix, Arizona, now relies on the Central Arizona Project (an aqueduct that runs from the Colorado River down through the desert to Phoenix) to supply much of its water. Recently, some people in water-starved southern California even proposed that an aqueduct be built from the Columbia River in Northern Oregon to supply some of the needs of southern California. In fact, divisions of water flowing down the eastern slope of the Sierra Nevada’s into Mono Lake (diversions for the Los Angeles area), lead to the Seminal Public Trust Case – the Mono Lake case.
Looking back over the development of these systems and the stress that urban growth has put on allocation of the resource, New Hampshire can probably glean a variety of lessons. First, as the State’s population increases and as available fresh water resources decrease (from use, contamination, and reservation of instream flow rights), the traditional riparian system may not be able to satisfy all the needs of New Hampshire users. "Reasonable use" tends to assume that there is enough water to satisfy everybody’s needs, assuming it is reasonably allocated. Looking ahead, that may not be the case, and it may be necessary to either modify the reasonable use system, or come up with some method of allocating an increasingly scarce resource. In addition, major urban areas may one day look to New Hampshire to help supply their water needs. Certainly, as Boston continues to grow, it may one day look North to help supply its needs. It is also not inconceivable that other metropolitan areas in southern New England, and New York City, may one day look to New Hampshire to supply it with water. For example, Mono Lake is several hundred miles from the Los Angeles area (compare this to how far Northern New Hampshire is from New York and Boston). Certainly, all of New Hampshire is much closer to New York and Boston (and Philadelphia and other major urban areas, for that matter), than is Los Angeles to the Columbia River. It is conceivable that one day New Hampshire may be responsible for supplying these urban areas with water, at the same time that it also needs to provide its residents and businesses with water. Traditional systems of water allocation will probably undergo significant change to meet these new conditions.
In addition, New Hampshire will certainly need to address the same sorts of issues that other states have already addressed concerning the allocation of the water resources to the protection of the natural environmental system. The instream flow rules recognize the value of leaving water in place under certain circumstances. Certain western states have wrestled for some time with instream flows, and how these rights must be allocated in the more restrictive prior appropriation system. Certainly, the New Hampshire water supply is more abundant than those western states. These non-consumptive uses will begin to compete with consumptive uses and put further stress on the system.
The methods of allocating surface water resources are being used increasingly to balance competing uses of groundwater. Our understanding of groundwater, and our expectations for the protection and use of this resource, are evolving comparatively rapidly. We in New Hampshire, like most other American jurisdictions, will, no doubt, continue to absorb approaches to water allocation selected from the experiences in many other jurisdictions. We will be well served by recognition that there are many different combinations of water laws from which we can draw.
Ultimately, the system we relied on in the past may not be able to suit our needs in the future. More people will be demanding access to an increasingly scarce resource. We’ll need to recognize this as we go forward and draw on lessons learned elsewhere.