Groundwater is a major importance of rural development in many countries of the world. As a result of its widespread distribution, low development cost, and generally excellent quality, it has been the fundamental resource allowing the rapid development of improved domestic water supplies for the rural population and in many areas has also supported a major increase of highly productive agricultural irrigation. Groundwater resources are thus vital for meeting an array of basic needs, from public health to poverty alleviation and economic development. Because of high rates of abstraction required for irrigation, however, in some areas there is significant concern about sustainability of the resource base, because of falling groundwater tables and near irreversible aquifer deterioration through saline intrusion. There are also additional sustainability concerns because of the increasing incidence of groundwater pollution from over-intensive or inadequately managed agricultural cultivation practices.