Water shortage in Sant Llorenç: Why a desalination plant alone is not enough

Water shortage in Sant Llorenç: Why a desalination plant alone is not enough

The decision for S'Illot is only the beginning – and we still hear too little about consequences and alternatives

Late afternoon in S'Illot: tourists stroll along the seafront promenade, children splash through shallow waves, and somewhere a lawn mower is running at a hotel complex. The municipality of Sant Llorenç, which includes Cala Millor, has announced plans to build a desalination plant in S'Illot to make the municipality less dependent on external water deliveries. At the same time, a new reservoir in Son Carrió and the replacement of old pipelines are on the list of improvements. Other towns are weighing similar options; for example, Palma examines desalination: Does the city need its own seawater plant?.

Key question: Is another desalination plant enough to permanently solve Sant Llorenç's water problems — and at what cost for the environment, energy consumption and local households?

The sober answer is: It is one building block, but not a cure-all. Desalination provides technically reliable drinking water, especially in summer months with high tourist demand. But it brings side effects: high electricity demand, potential impact on the sea from salty wastewater (brine), and not insignificant investment and operating costs. In a region where the electricity mix is still largely fossil-based, this means additional CO2 emissions — something that has so far been discussed too little in the public debate. The broader context of Mallorca's water stress is discussed in When the Tap Runs Scarcer: Mallorca Between a Tourism Boom and a Dwindling Water Source.

What is missing from the public debate: clear information on financing, energy sources and environmental protection. Will the plant be powered by renewable energy? What are the expected operating and maintenance costs — and who will ultimately pay the bill: the municipality, tourism businesses or consumers? What measures are planned to dispose of the produced brine in an environmentally compatible way? Such questions should be answered before a major tender, not only after commissioning. Questions about financing and tourist levies have been raised in pieces such as Water for the North: Alcúdia Relies on Desalination — Paid for by the Tourist Tax.

An everyday scenario from Mallorca: in summer you often see gardeners watering flower beds at ten in the morning, or hotels topping up pools daily. Seasonal business behavior drives consumption. Reporting on hotel responsibility can be found in Water scarcity in Mallorca: Why hotels must now take responsibility. A plant in S'Illot will meet demand, but it does not solve the underlying problem: we consume too much, especially during the summer months.

Concrete approaches that should now be implemented in parallel with desalination:

1. Plan energy and technology cleanly: The desalination plant as a modular reverse-osmosis operation, coupled with local solar installations or long-term power purchase agreements with renewable producers. Storage (batteries) or night-time operation could shave peak demand.

2. Brine management: As gentle discharge as possible, use in industrial processes or dilution with retention basins; an independent study on marine compatibility should be part of every tender.

3. Leak reduction and infrastructure: The planned new pipes in the municipality are a low-hanging fruit. Old networks lose water — the climate advantage of a desalination plant shrinks if side losses remain.

4. Water saving in tourism: Mandatory measures for hotels such as flow restrictors, smart meters, greywater and rainwater use for garden/pool maintenance. Seasonal tariffs that make consumption peaks more expensive could provide a real lever.

5. Transparency and participation: Before the tender: environmental impact assessment, cost-benefit analysis, citizen and hotelier workshops. Without local acceptance, projects remain vulnerable to disputes and delays.

Politics and administration can also explore EU funding programs for climate and water and form partnerships with neighboring municipalities. A desalination plant in S'Illot can only be sustainable if it is part of a package: storage, pipelines, conservation programs and clean energy.

Conclusion: The announcement from Sant Llorenç is a realistic step given rising summer demand. But those who rely only on technology and ignore everyday practices — garden hoses, overfilled pools, hotel systems — miss the chance to become permanently more resilient. The real challenge is not only water supply, but a comprehensive change: less wasted water, better infrastructure and energy that does not create new problems. If that succeeds, the promenade in S'Illot will still feel fresh in ten years without household bills jumping sharply.

On-site tip: Anyone who wants to get an impression in person should go to the beach at S'Illot or to Son Carrió on a late morning and look for places where pipes look old, flower beds are overwatered or hotels still neglect basic water-saving measures. That often tells you more than numbers on paper.