If you drive the coastal road between the Parador and the start of the Cabo de San Antonio climb, you pass a low, industrial-looking building that most people barely notice. That’s the desalination plant. It doesn’t look dramatic because it wasn’t built to be shown off. It sits just behind the coast on purpose, close enough for a straight seawater intake pipe but far enough back from the real wave action so it doesn’t get hammered when the storms come in.
Where the seawater comes from
The intake pipe runs straight out from this section of coast. It isn’t on the sands of the Arenal or tucked under the port walls. The pipe sits offshore at a depth where the water is stable, not full of stirred-up sand. The intake sits far enough out that storms don’t yank debris into it, but not so far that maintenance becomes a major job. From the outside it looks like nothing. Inside the plant, it arrives as raw seawater through a coarse pre-filter that stops the obvious things, and from there it goes into the real machinery.
How the membranes work, in normal English
Reverse osmosis is the official term. In practice, the plant forces seawater through a series of long cylindrical membranes. They look like tightly rolled carpets stored inside pressure tubes. When seawater is pushed against these layers at very high pressure, fresh water makes its way through the microscopic pores while the brine, minerals and everything else stays on the other side. It’s not magic. It’s pressure plus a physical barrier.
The fresh water comes out the other end and is blended with other sources. The leftover brine goes back out to sea through a separate pipe that disperses it at a controlled dilution. All clever stuff huh?
Why the plant sits here and not at the port
People often assume the port would have been the obvious place. It wasn’t. Ports are full of suspended grit, fuel residue, boat waste, fishing activity and constant turbulence. Seawater quality there goes up and down with every storm or ferry movement. A desalination plant needs consistency because membranes clog if the intake quality swings too much.
The stretch of coast where the plant sits is calmer. There are no boats coming and going, no dredging, no fishing nets. Just open water with predictable conditions. It also allowed for a straight horizontal pipe run with no weird angles, which matters both for pressure and for cleaning the pipe.
The aquifer under Montgó
The other half of Jávea’s water isn’t hidden in machinery. It’s under your feet. The aquifer is basically a natural sponge of porous rock sitting beneath the lower slopes of Montgó and running out under the Gorgos riverbed. Rain collects high on the mountain, infiltrates through cracks in the limestone and slowly feeds this underground reservoir.
When people talk about “the water table” here, they’re talking about the level of this aquifer. In the 80s and 90s, summers were drier and the town smaller, but demand grew faster than the aquifer could recover. Wells lowered, the quality changed at times, and that was the warning sign that the town needed a second source. Anyone else remember brown sludge coming out of the taps from time to time in the late 80s?
The timeline, roughly as locals remember it
1980s
Most water came from wells tapping the Montgó aquifer. Rainfall patterns were still reasonable but holiday growth started accelerating.
Early 1990s
Demand rose faster. Summers stretched out longer. There were years when supply looked tight and the aquifer was being pushed too far. The town understood this wouldn’t hold forever.
Late 1990s
Serious planning began for a desalination plant. Locations were considered. The port was ruled out early because of water quality. The final site was chosen on the flat strip between Montañar II and the beginning of Cabo de San Antonio.
2002
The desalination plant became operational. It wasn’t at full capacity from day one, but the system was in place. The maximum daily production, once all four racks were running, reached around twenty eight thousand cubic metres. That covered the summer peak and stopped the town depending entirely on the aquifer.
2000s–2010s
Pipe renewal programmes, pressure adjustments and network balancing were carried out bit by bit. Not glamorous work, but necessary.
2020s
The plant regularly runs at high capacity in August. The aquifer is still used, but it isn’t strained the way it once was. The system is stable because it now has two reliable sources instead of one vulnerable one.
What the desalination building is actually used for
Inside the building:
• the seawater intake pumps
• the sand and gravel pre-filtration stage
• the cartridge filters
• the high-pressure pumps that feed the membranes
• the reverse osmosis racks themselves
• monitoring and water-blending systems
• the brine outflow regulation system
It isn’t a storage tank, a lab, an office block or anything fancy. It’s a working plant. Most of the building is just long rooms of pipes, pumps and pressure tubes.
The part people never talk about
The plant doesn’t just push out pure desalinated water (hence why it can sometimes taste a little salty). The town blends desalinated water with groundwater at different ratios depending on the season. In winter the blend tilts towards the aquifer. In August it tilts towards desalination. This keeps pressure stable and stops the aquifer being hammered in dry years.
The short version
Unlike most coastal towns, Jávea built a proper backup system before things got critical. The aquifer still matters. The desalination plant matters just as much. And the whole thing holds together because the seawater intake is placed where the water stays clean, the membranes are protected from constant clogging, and the demand is smoothed out by careful blending.
Interesting stuff.
