An island out of step with its own landscape

Synerra is based on Tzia (Kea) - where the questions we work on are visible from the road.

Anyone who has driven through the island over the past three summers has seen it. Almond trees that stood for decades without a drop of irrigation are dead on their feet. Springs that were fixed points on the map, places where you stopped, filled a bottle, watered animals, have stopped running. Flea, one of the island's most important springs, is the exception, and only recently: it showed the first signs of recovery in 2026.

None of this is the residue of one hot summer.

What the record shows

Climatebook published an analysis on 2 September 2026 of the daily rainfall series from the National Observatory of Athens station at Kastriani, which has been recording since 2010. The findings are unambiguous.

Between 2010 and 2019, average annual rainfall at Kastriani was around 465 mm. Across 2020 to 2025 it fell to roughly 276 mm, a drop of about 41%. Measured by hydrological year (October to September), the picture is the same, with 2023–24 the driest of the recent period at just 232 mm.

The totals are only half the story. The other half is the spacing. In 2020-21 the island recorded 212 consecutive days without a single day of rain above 5 mm. In 2023-24 that stretch reached 224 days, and in 2024-25 it was 158. Over the last five years, an average of about 62% of each year's rain arrived within the ten wettest days. Long dry periods, punctuated by short bursts that run off faster than the ground can take them in.

This year has been kinder, with 297.4 mm to the end of August and 517 mm since October 2025. One better year does not refill an aquifer that has been drawn down for half a decade.

Source: Climatebook, Κέα: Πέντε χρόνια ανομβρίας άλλαξαν το τοπίο του νησιού

The oaks that nobody is counting

Above the coastal belt, across the island's higher ground, Tzia carries something no other island in the Cyclades has: standing woodland of valonia oak, Quercus ithaburensis subsp. macrolepis, the velanidia. The species is found elsewhere in Greece and around the eastern Mediterranean, but the Aegean has almost none of it left. Tzia's stands are among the last.

For most of the island's history these trees were both an economy and visually appealing. The cup of the acorn, the chamada, is dense with tannins, and Tzia sold it to the tanneries of Kalloni on Lesvos and onward into Europe. Harvest began in July before the fruit ripened, or the cups were gathered from the ground into September. Charcoal kilns worked beside the groves. Pigs were fattened on the acorns themselves. When synthetic chemicals replaced natural tanning agents, the trade collapsed and the groves went quiet. They are protected today, and there have been recent attempts to bring the harvest back.

Acorn trees in Stavroudaki, Kea - photo by Sokratis Vlachakis

Here is the part that should worry us, and the part we cannot yet prove.

A mature valonia oak is a drought specialist. Deep-rooted, slow, built for heat, it can absorb five bad years in a way an almond tree cannot. So the canopy looks fine, and the visible landscape story stays with the dead almonds and the empty springs. The vulnerability sits somewhere less photogenic: in regeneration.

Acorn production falls under sustained water and heat stress, and seedlings need soil moisture through their first summers to establish at all. Add the grazing pressure that comes with a livestock island and you get the classic failure mode of this species, which is a woodland of old trees with almost nothing coming up behind them. That kind of loss does not show up for thirty years, and by the time it does, it is finished.

We are stating this as a hypothesis, because as far as we can establish there is no published time series on acorn yield, seedling survival or stand structure for Tzia's oaks. There should be. It is a small, cheap, tractable piece of monitoring for a habitat with no real replacement in the Aegean.

Springs, cisterns, and a 200 m³ answer

Small islands have no easy fallback. Tzia cannot lean on an external supply when the rain fails, and shipping water in by tanker is expensive and energy-hungry. In May 2026, residents were publicly raising water quality concerns, and the mayor confirmed that while there had been no supply cuts, drought has affected the island in recent years (source: https://cyclades24.gr/2026/05/i-kea-anazita-lysi-sto-chronio-provlima-nerou-oi-katoikoi-diamartyrontai-gia-tin-poiotita-tou/).

Meanwhile demand climbs in exactly the months when supply is thinnest, with dozens of new swimming pools built each year.

A desalination unit of 200 m³ per day has been approved for the island. It will help. On its own it is not a water strategy. On an island whose natural resources are under this much pressure, the work that has to run alongside it is unglamorous and well understood: cutting network losses, rainwater harvesting and the rehabilitation of the cistern stock the island already has, reuse where it is feasible, and above all management of demand. Adding supply while demand grows without limit simply raises the cost of the same problem.

Tourism is one part of the living

It is tempting to read a Cycladic island as a summer economy with a permanent population attached. Tzia does not work that way. Livestock is the main occupation of its residents, with smaller-scale farming, vines, fishing, and a beekeeping tradition the island traces back to Aristaios himself. The municipality's own rural development plan recorded 47 registered beekeepers working 2,305 hives.

Every one of those activities meets the drought before tourism does.

Grazing is the first casualty: when the winter rains fail, the hills produce less, and feed that used to be free becomes a purchased input on a thin margin. Beekeeping depends on wild thyme and the flowering of a landscape that dry winters suppress, so yields fall for reasons no beekeeper can manage from the apiary. Rainfed almonds do not adapt, they die. And all of it competes for the same aquifer as the pools.

Karthea Archeological Site, Kea - photo by Sokratis Vlachakis

The conversation we have not had

Synerra has not yet sat down with the people this is happening to. That is the honest position, and it is the gap this piece exists to close.

The data above describes rainfall. It does not describe what a herder did when the fodder bill doubled, which fields were abandoned and which were replanted, who dug deeper, who left, who came back, which cisterns were repaired and which were sold with the house. It does not record where the springs were, what they were called, when each one stopped, and who remembers them running. That knowledge exists on the island right now, held by people in their seventies and eighties, and it is not written down anywhere.

We are proposing to record it. Concretely:

• Oral histories of water, mapping named springs, wells and cisterns against the years they failed, with the people who used them.

• Livelihood interviews with herders, beekeepers, growers and fishers, on costs, yields, abandonment and the adaptations already made without any programme's help.

• A baseline on the oaks: stand extent, age structure, regeneration and acorn yield, so there is something to measure the next decade against.

• Water demand accounting that treats permanent residents, seasonal housing and tourism as separate lines rather than one number.

Adaptation on Tzia is already happening. It is being improvised, individually, without data and without support. The least useful thing anyone can do is arrive with a plan. The most useful is to ask, and then to listen carefully enough that what people already know ends up counting as evidence.

Road to Ioulis, north-eastern side of Kea - photo by Sokratis Vlachakis