Greece is facing an increasingly severe water shortage, with alarming declines in both surface and underground reserves. The situation is compounded by over-extraction for agricultural and tourism purposes, outdated infrastructure, and the absence of a clear national water strategy.

Underground Reserves Under Threat

New data from the Hellenic Survey of Geology and Mineral Exploration (EAGME) reveals that many of Greece’s underground aquifers—often considered a strategic reserve due to their resistance to pollution and evaporation—are nearing critical depletion levels. This is especially troubling as these aquifers play a key role in supplying water to both urban and rural populations.

Regions under the greatest strain include much of the Aegean islands, Eastern Argolida, and areas of Chalkidiki such as Moudania and Kassandra, where potable water is increasingly scarce. According to Vassilis Zorapas, head of EAGME’s Hydrogeology and Hydrology Division, key pressures on groundwater include declining rainfall, seawater intrusion, and unsustainable human activity.

Dry Conditions and Mismanagement Compound the Crisis

Prolonged drought, particularly in southern and eastern Greece—including Crete, the Peloponnese, and several Cycladic islands—has sharply reduced rainfall and snowfall. These factors, coupled with inefficient irrigation and unmanaged water use, are pushing several aquifers beyond recovery.

For instance, in the Moires region of Crete, groundwater levels have dropped over 25 meters since 2014. While part of this is due to drought, EAGME points out that excessive pumping for irrigation is the primary driver—even during wetter years. In some coastal areas like Argolida and Syros, saltwater has replaced lost freshwater, rendering supplies undrinkable.

Seawater intrusion occurs when over-pumping causes freshwater levels to fall below sea level, allowing saltwater to seep in. This has been observed in numerous coastal zones, including Naxos, Chios, Ierapetra, and the Evros Delta.

Surface Water Also in Decline

Surface reservoirs are not faring much better. Lake Mornos, a key water source for Athens, is currently 150 million cubic meters below last year’s levels, according to data from Athens Water Supply and Sewerage Company (EYDAP). Together with the Evinos, Marathon, and Yliki reservoirs, these sources currently hold enough water for only two more years—at best.

epa01183694 YEARENDER 2007 JANUARY A schoolgirl treads carefully as she crosses a pitted field in what was once the verdant Thessaly plain 26 January 2007. The ongoing drought in Greece is now severely threatning agricultural cultivations. EPA/VASSILIKI PASCHALI

Athens, which houses nearly half of Greece’s population, is uniquely dependent on these reservoirs. Their reduced replenishment—due largely to low precipitation and declining snowfall in recent years—places the capital in a precarious position.

Poor Infrastructure and Policy Gaps

Beyond natural factors, the water crisis is being worsened by human error. Water transportation networks in Greece reportedly lose more than 50% of their supply due to leakage. Additionally, a lack of regulation and enforcement surrounding water extraction—especially from unauthorized boreholes—has allowed the problem to spiral.

Zorapas highlights the absence of a long-term strategy for water use in agriculture and tourism as a core issue. Agriculture accounts for 85% of the country’s water consumption, yet irrigation is often poorly managed and inefficient. Meanwhile, the growing tourism industry puts seasonal pressure on already overburdened systems, particularly on islands with limited natural reserves.

Over the past 25 years, Greece’s annual water consumption has more than doubled—from around 800 million cubic meters in 2000 to 1.8 billion cubic meters today. This surge is attributed to increased tourism, expanded infrastructure, and rising living standards.

Limited Solutions and Urgent Need for Change

Zorapas warns that there are no immediate or universal solutions. Instead, each region must aim to mitigate the problem based on its own capabilities. In some areas, this may involve restricting visitor numbers and tourism infrastructure in line with available water resources. In others, switching to less water-intensive crops may be the only viable path forward.

Data from EAGME indicates that between 2020 and 2024, Greece’s southern and eastern regions experienced a marked decline in rainfall. For example, in Tripoli, average annual rainfall dropped from 750mm to just 617mm—equivalent to losing nearly an entire hydrological year.