History and aims

Uncertainty is a characteristic of water resource availability in the Segura river basin, with a markedly Mediterranean system of rainfall, where the water cumulative flows mean that the resources available are clearly insufficient (structural deficit). Whether it is due to natural causes or as a result of climatic changes caused by human activity, these particularly dry events seem to have become more frequent and more persistent over recent years. By way of example, we can mention the long periods of drought registered between the hydrological years 1979/80 and 1984/85, or the one that began at the beginning of the nineties and ended in 1995. This is why it is urgent that a series of studies and actions be implemented in order to reduce the incidence of drought on the different uses of the water in the river basin. These activities must be mainly aimed at optimizing the management of the resources available, before and during the periods of drought

Fuensanta reservoir (2005)

Law 10/2001, of 5 July, of the National Hydrological Plan states, in its Article 27 on Drought Management, the need to carry out the following actions:

1. Establishment for inter-community basins, on the part of the Ministry of Environment, a global system of hydrological indicators that allows the prediction of these situations and that can be used as general reference by the Basin Organisation for the formal declaration of situations of alert and of temporary drought.
2. The elaboration, by the Basin Organisation, within the territorial environments of their Hydrological Plans, of special Action Plans in situations of alert and temporary drought, including regulations for using the systems and the measures to be adopted related with the use of public water resources. These plans would be approved by the Ministry of Environment, subject to approval by the Basin Water Council.
3. The drawing up by the public administrations responsible for urban supply systems for towns of 20,000 inhabitants or more, individually or jointly, of an Emergency Plan for situations of drought. These plans, which will be published by the Basin Organisation or corresponding Water Authority, must take into account the regulations and measures laid down in the special Plans referred to in the previous point.

Valdeinfierno reservoir(2005)

Likewise, the Hydrological Plan of the Segura River Basin, approved by R.D. 1664/1998 of 24 July, sets forth a series of actions aimed at:

• Identifying the periods of drought .
• Establishing the actions to be carried out in the event of drought.
• Determining amendments in operating regulations of reservoirs and aquifers, as well as allocation of resources.
• Adjusting the restrictions to be imposed for the different uses.
• Predetermining the moment and way to incorporate strategic reserves.
• Establishing a way to estimate cumulative flows and demands in order to be able to plan campaigns.
• Drawing up of Drought Plans.

Taking into account all the above-mentioned, a Special Plan for Situations of Alert and Temporary Drought in the Segura River Basin (P.E.S) has been approved by the MAM/698/2007 Order, on march, 21th, which will also be included in the Programme of Measures of the Water Framework Directive for the year 2008. Insofar as this Plan was not available, in October 2005, the CHS Governing Body approved the Protocol of Actions to be taken in the event of Drought..

This Plan determines which mechanisms are more suitable for making medium and short-term weather forecasts, in which conditions of availability of the resource the basin organisation, as competent authority, has to determine situations of caution/alert or even drought, and, evidently, which measures or actions are to be taken in order to manage the resources better in each scenario, laying down the necessary mechanisms for coordination and information.