Monday, September 21, 2009

Regulation of Groundwater Use in the West

Over the last several decades, water users in the western United States have increasingly turned to groundwater resources to support agriculture, enhance economic expansion, and spur urban growth. As can be seen above in the US Geological Survey chart, the western 16 states account for the lion’s share of groundwater use in the United States. It is reported that the western states account for approximately two-thirds of the groundwater use in a “typical” year.

One of the defining features of the western U.S. is its aridity. In an arid environment, water is often diverted from streams and transported, sometimes great distances, to mines, farms, cities, and towns. Developing surface water supplies requires two intensive expensive efforts. The first is to plan, build, and maintain a surface water transport project. This entail building diversion structures, a distribution system, and storage reservoirs. Second, administrating and maintaining the system, including developing information about and monitoring the physical setting, negotiating over the location and design of the water system, and monitoring and enforcing agreements, are significant. Managing water allocations in a western state is very much managing the economy of the state. As water demand raises past supply the regulatory scheme or the state economies are doomed to failure. We are incapable of designing the right economy to allocate scarce resources to over time. What is right for today is not adoptive to the future. Central planning and allocation is rigid.

The development of groundwater resources and their use occurred after the system of surface water management was in place. The west had already developed the institutions necessary to allocate, diver, distribute and use the surface water. The rapid development of groundwater in the west occurred before any limits were placed on its use. Initially many of the western states recognized some variant of the “reasonable use” doctrine. The reasonable use doctrine allows landowners overlying a groundwater basin to pump as much water as they can put to reasonable use on their land. This doctrine was intended only to limit waste of water not limit pumping. Groundwater codes were adopted in response to the intense conflicts that broke out.

In adopting groundwater codes, most western states extended the prior appropriation doctrine to cover groundwater. Beginning with New Mexico in 1931 and ending with Montana in 1961, groundwater in 11 of the 16 western states was governed by the prior appropriation system. Existing wells were given priority dates, new wells were allowed only with permits granted by state water agencies. Permits could be denied where an aquifer was over appropriated. The priority system was extended to groundwater because it was familiar, well accepted and seemed to work for surface water. It was believed that this system would allow satisfactory regulation of groundwater use much in the same way that it had allowed regulation of surface water. In states that do not apply the prior appropriation doctrine to tributary groundwater, intense conflict has emerged around the effects of pumping on surface water flows. Arizona is an extreme example of a state that uses distinct bodies of law and regulation to govern ground and surface water with no legal recognition of the physical connection between the two sources of water (Glennon 2003).

Unfortunately, the hydrologic connections between groundwater and surface water were not understood at the time. Hydrology determines the long term success of prior appropriation as a groundwater management scheme. Where groundwater basin is not hydrologically connected to a surface water source, prior appropriation has resulted in groundwater mining, non renewable use of groundwater. In locations where the groundwater basins are hydrologically connected to surface water sources the prior appropriations has had the effect of protecting surface water flows from over pumping because surface water rights holder are invariable senior to well pumpers. The prior appropriations doctrine has not resolved intense conflict between groundwater, surface water users and ecological demands.

The prior appropriation doctrine has failed to resolve the conflicts between groundwater and surface water users or adequately managed groundwater basin storage. The prior appropriation doctrine as conceived and administered was not designed to conserve water. It was developed in a time when population was still sparse, water supplies were believed to be plentiful and development and growth were to be encouraged. This management scheme has resulted in non sustainable use of groundwater. Today, the “reasonable use” doctrine is still in effect in Arizona, Oklahoma and Texas. Nebraska attempts to coordinate the management of ground and surface water recognizing their hydraulic connection. As stated above 11 states govern groundwater under the prior surface water appropriation. California does not fall under any of these schemes but locally restricts well permits and has a total of 27 local ordnances under which local governments attempt to regulate groundwater. . The eastern states do not as a rule regulate groundwater use.

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