According to the Balearic Government's director-general of water resources, Joan Calafat, there is one pool for every fourteen residents of the Balearics, whereas on the mainland there are between 30 and 35 per resident. In this respect, there are at least twice as many pools as on the mainland - 79,588 of them legal, as recorded by the land registry, plus an estimated 20,000 illegal pools.
Between 2015 and 2023, 6,341 pools were built. In the past two years, another 3,920 have been added. Two factors help explain this - the building of houses in the countryside, all of which have pools, and especially the increasing number of pools for newly built houses. There is also plenty of evidence pointing to increased property values because of a pool.
Away from Palma, Calvia has the most pools - 5,233, one for every nine people. These include hotel pools. In Marratxi, a municipality with plenty of detached houses but hardly any hotels, there are 4,414.
All these pools have to be considered in the context of concerns about water supplies. Two water demand regions of Mallorca, Arta and the Pla (Plain), are on drought alert, the level below drought emergency. The rest of the island is on pre-drought alert, with certain municipalities in the Tramuntana Mountains - Deia is one - experiencing shortages in the summer.
Arta Town Hall has applied a moratorium on the granting of licences for new pools, while Council of Mallorca regulations have cut the permitted size of pools.
Joan Calafat says these size restrictions help reduce the amount of water evaporation. His department estimates that between seven and eight cubic hectometres of water are lost annually due to evaporation from pools in the whole of the Balearics. Another cubic hectometre is lost during the cleaning of filters. All this water loss is greater than what the Gorg Blau reservoir holds when it is full. Pools have to be regularly topped up because of evaporation, part of pools' three per cent of total water consumption.
Calafat stresses the importance of educating the public about water consumption and of investing in water networks to optimise them and prevent leaks. The current government, he says, is making significant investments in the water cycle. He points out that there are times when a quarter of the water pumped into the network is from desalination plants.