This paper evaluates the risk of a water crisis – a substantial, sudden reduction in water supply – in the Monterrey Metropolitan Area (MMA), posed by climate threats and the vulnerability of its water supply system. Our analysis of long-term precipitation, water supply and water availability data reveals that the MMA is highly vulnerable to recurring periods of exceptionally low precipitation and scarce surface water availability. We identify two episodes in the recent past (1998 and 2013) when the MMA water supply system almost collapsed as reservoirs neared depletion in the face of abnormally dry weather. Furthermore our climate projections point to warmer and drier future conditions for the region and consequently, heightened climate threats. We conclude that the risk of a water crisis in the MMA is substantial and probably will increase due to climate change. This establishes a clear and pressing need for a comprehensive package of adaptation measures to mitigate the consequences of a water crisis should one occur as well as to reduce the likelihood of such an event

Mexico is exposed to droughts and vulnerable to their impacts. Despite a history of serious economic and social consequences from drought, until recently national water policy did not acknowledge this type of natural disaster as a priority issue. This paper analyses how drought policy in Mexico has evolved since the creation of the National Water Commission in 1989 up to 2013, when the most specific initiative in that regard was introduced: the National Drought Program (Programa Nacional Contra la Sequía, PRONACOSE). Over that period of time drought has slowly but steadily gained importance in national water planning and management. Significant initiatives have been implemented, including a national drought early warning and monitoring system. Nevertheless, efforts still focus on compensating economic losses after the fact and little has been achieved in terms of reducing the country's vulnerability to drought. There is a great need to increase public awareness and boost the scientific knowledge necessary for the design of appropriate preventive measures. A long way remains to establish an effective, forward-looking, integrated and preventive drought management model.

Drought poses significant risks to society, in particular irrigated-crop production, which accounts for a large share of global freshwater use. Given its key role in the production of food, feed and fiber crops, there exists a need for policy measures to prevent and mitigate the impacts of drought on irrigated agriculture. This paper proposes that the design of drought policy should take into account actual farmer behavior in response to water scarcity. To this end, we offer a detailed analysis of land allocation and crop-choice decisions over time in an irrigation district located in the dry plains of Northern Mexico. We find that farmers systematically change their crop mix in response to water availability. In particular, in times of drought, irrigation water flows to higher-yield and higher-price crops (which also require more intense irrigation) to the detriment of less water-demanding (but lower value) crops. Farmers use water with the goal of earning a living—economizing on water per se has no relevance in that context. Policies that do not explicitly recognize this may result in ineffective, inefficient and/or unfair outcomes.