The University of the Balearic Islands and the regional government's directorate for water resources have established three scenarios of water consumption in Mallorca for the next ten years.
These scenarios take account of what in recent years has been taken to be average consumption per day per inhabitant - 250 litres. This is now questioned as being unrealistic. A scenario more closely aligned with actual usage and tourism growth is the one that the government is focused on. This envisages an increase of 20.8 cubic hectometres, equivalent to the annual production of a conventional desalination plant.
Under this scenario, the anticipated total consumption in Mallorca by 2035 would be 130.3 cubic hectometres. The two other scenarios predict 117.2 and 122.
The average annual contribution from the two giant reservoirs in the Tramuntana - Cúber and Gorg Blau - is 7.7 cubic hectometres. At an absolute maximum, the reservoirs can supply 12 cubic hectometres. The bulk of Mallorca's water therefore clearly comes from other sources, and the challenge, other than the risk of inadequate rainfall, is overexploitation of aquifers.
This being a problem that is well recognised, the scenarios factor in the need for aquifers to recover, which will happen if there is adequate rainfall. They also consider the immediate target of cutting losses from the water network by 17%. Targets for individual municipalities have been set.
Underpinning the management of water supplies going forward is the greater use of desalination. There are currently three plants in Mallorca - Alcudia, Andratx and Palma. A fourth is to be built, quite probably in Felanitx. This will be able to supply the island's eastern and southern regions and the intention is to connect it to the main water network once this reaches Manacor.
The extension of the water network will take supplies to the island's Pla (Plain) region, currently the only part of Mallorca on drought alert; everywhere else is on pre-alert for drought.
Forty million euros are being invested in improvements to the Palma desalination plant, while the Alcudia plant is to be expanded. At present it only supplies Pollensa and Playa de Muro. In the future, Alcudia itself plus Sa Pobla and Santa Margalida will be supplied.