This winter left behind a sense of cautious optimism regarding water reserves in Attica. Rainfall, which returned with intensity in recent days, proved more generous than in previous years, allowing the reservoirs that supply the Athens basin to recover some of their losses.
The reserve situation improved noticeably, yet this is not enough to dispel concern. The need to implement critical water resource management projects remains fully urgent, as the hard language of numbers makes clear.
According to the most recent data, on March 31, 2026, total reserves across the four reservoirs (Mornos, Evinos, Yliki, Marathon) stood at 723.6 million cubic meters. A year earlier, on the same date, they were at 651 million cubic meters, while in 2024 they were significantly higher at 929.2 million cubic meters. Going further back, in 2023 reserves exceeded 1.1 billion cubic meters, and in 2022 they approached 1.32 billion cubic meters.
The New Normal
The comparison is revealing and clearly reflects the new normal taking shape under the pressure of the climate crisis. Despite this year’s recovery, available reserves remain well below the safety levels of previous years. The three preceding years were marked by intense water shortages, with water inflows falling dramatically short of outflows.
Specifically, while annual consumption hovered around 400 million cubic meters, inflows were limited to roughly 150 million, resulting in an annual deficit of around 250 million cubic meters. This year the balance nearly zeroed out, as what was drawn from the reservoirs was almost fully replenished.
However, as EYDAP (Athens Water Supply and Sewerage Company) president Giorgos Stergiou noted at the World Water Day 2026 Forum just days ago, “the problem has not been solved, nor should we be complacent. We need to move forward with greater boldness and courage in implementing the necessary projects.”
The “Evrytos” Project
The strategy to secure Attica’s water supply moves along two axes: large, long-term infrastructure projects on one hand, and immediate interventions that serve as a “bridge” until those are completed on the other.
Where do things stand today? A pivotal role in the long-term plan belongs to the “Evrytos” project, a partial diversion of the Krikeliotis and Karpenisiotis rivers toward Lake Evinos, an investment worth €535 million. An open competitive tender is now expected to be announced in the summer of 2026. As Stergiou noted, “there are no longer grounds to invoke the emergency provisions.” In other words, the process will not follow the closed-invitation model used for projects in Thessaly, where major construction players were invited directly. The project’s importance is critical: even under unfavorable hydrological conditions, it could deliver up to 200 million cubic meters of water per year. It is estimated to take roughly two and a half years to complete from the start of construction, with a delivery horizon of the first half of 2029, barring delays. Alternative scenarios, such as desalination units, are also being examined, though they come with high cost and energy burden.
Drilling Works
The “Evrytos” project is part of a broader investment program of around €2.5 billion aimed at securing Attica’s water supply for the coming decades. Until the river diversion is realized, emphasis is placed on immediate interventions that can strengthen the system.
Four such interventions are estimated to add up to 149 million cubic meters of water per year, including the exploitation of the Mavrosouvala wells (32 million cubic meters annually) and the reduction of the environmental flow from the Evinos river, which already saves 22 million cubic meters per year.
Additionally, the activation of 11 wells in southeastern Yliki, in the “Ougroi” area, has begun. According to sources speaking to To Vima, four of them are already operational, while the rest are expected to be fully up and running by the end of April, offering up to 50 million cubic meters per year. The first phase of exploiting underground reserves of the Boeotian Kifissos river is also underway, with an estimated yield of 45 million cubic meters.
However, these interventions have clear “emergency” characteristics. According to Stergiou, pumping water must be used sparingly as it involves significant energy costs and a negative environmental footprint — in contrast to supplying Attica from the Evinos–Mornos branch, where water flows by gravity and requires no energy.
