Review.Water resources deficit and water engineering

The increasing demand of water for different uses, together with the variable availability of this resource, which is due to the increasingly frequent periods of drought, make necessary to undertake a set of structural and contextual actions to cope with the permanent or temporary scarcity situations. Within the search for solutions to the progressively more widespread situation of limited water availability for agriculture, this paper aims to state the role that engineering can play to face up this deficit, taking into account the social, economic, and environmental issues of water, together with the priority of uses. Structural measures can help to:1) increase the water availability (increased or more flexible supply through reservoirs, water transfers, water rights interchange centres, desalination, reuse, aquifer recovery, and conjunctive use of surface water and groundwater), and 2) rationalize water consumption by improving demand management, including the irrigation management improvement, as well as maximizing the efficiency of irrigation systems. In addition to these measures, other social issues can be implemented through public awareness and education, adequate economic policies, legislative adaptation, and technical support to municipalities and water use associations. Thus, to face up water scarcity in a region it is necessary to identify the different water sources, including alternative sources such as desalination and reuse, and develop an appropriate model of management as well as infrastructure for water storage and regulation.