Mitigation of groundwater overdraft could result in water shortages for some users, and secondary impacts. A shift to greater reliance on groundwater versus surface-water supplies would also mean that some municipal and industrial systems would lose some of their current flexibility and have more constrained and vulnerable systems. Responses Many areas of the Southwest already experience groundwater overdraft, competition between sectors for limited supplies, and fluctuations in the availability of surface water supplies. Thus the municipal and industrial water sector is already familiar with a number of possible responses to reduced supplies of and increased demand for water. The transfer of water from agricultural use to municipal and industrial use is a current trend in the Southwest that is expected to continue.
Urban users are generally willing to pay more for water and land than are agricultural users.
Interregional transport of surface water is an important component of water supply for the Southwest and could increase in the future. However, water from the Colorado River and Rio Grande is completely allocated, and there are substantial economic and political barriers to transporting water from more distant sources. Desalination could be used to augment fresh-water supplies, especially if new technology can help lower costs. At present it is not economically feasible in comparison to other means of augmenting municipal and industrial supplies. Optimal use of existing water supplies of differing quality, e.g. delivery of non-potable supplies such as reclaimed water for some users, should also be examined.