Attica is experiencing one of the most severe drought periods of recent decades, recorded by the National Technical University of Athens (NTUA) as the second most significant dry episode after 1988–1994.

The region faces persistently reduced inflows into reservoirs, which continue to empty and approach historically low levels — the harshest condition the water supply system of Athens has seen in more than thirty years.

This is not simply a temporary drop but a prolonged period of drought, during which every drop counts and every cubic meter becomes a matter of planning, foresight, and ultimately survival for a system that was long considered stable and taken for granted.

According to the management plan prepared by NTUA for EYDAP for the 2025–2026 hydrological period, the crisis is not caused by overconsumption but by a lack of water.

The numbers leave little room for optimism without a plan: the reservoirs are below 30% of their capacity, the Boeotian Kifisos river has been below average for five consecutive years, and network losses have exceeded 12%, failing to retain quantities that would normally be sufficient.

What the measures aim to achieve

Athens is not in immediate danger of running out of water — but it is at risk if inactivity continues.

Declaring Attica — along with Meganisi in Lefkada, following Leros and Patmos — in a state of emergency due to drought is not symbolic. It is a necessary step allowing the state, municipalities, and EYDAP to bypass lengthy public procurement procedures and move forward quickly with essential water-supply infrastructure.

Under emergency status, major works that would typically require years of approvals, environmental studies, appeals, and tenders can now proceed through fast-track processes, including direct assignments where immediate implementation is needed — similar to the “Daniel” projects in Thessaly.

This also compresses the time required for permits and approvals, allowing studies and environmental processes to be completed in months rather than years — critical when delays are measured in cubic meters of water.

Declaring a region in a state of emergency does not solve drought but acts as a multiplier of speed, enabling proactive action through reservoir works, pipelines, new boreholes, and fast-track water management projects.

The state of EYDAP’s reservoirs

Reservoir levels are dropping rapidly. Lake Yliki is at only 31% of capacity (175.4 million m³), down from a former 560.4 million m³. This dramatic drop returns levels to those of 2001.

Marathon reservoir, historically symbolic, can no longer significantly support the system due to extremely low annual inflows (3–6 million m³ versus the old 12.8 million m³), serving mainly a regulatory role.

This brings the Mavrosouvala boreholes — and other underground water works — back into prominence. Historically used only in emergencies, they are now pumping water at rates not seen since 1994–95, providing critical relief.

Water consumption levels

Athens is not consuming more water — it simply has less available. Total water abstraction remains around 460–500 million m³ annually.

Irrigation in the Kopais plain is the second-largest water use after environmental flows, consuming 30–35 million m³ annually. NTUA’s recommendation suggests irrigation may need to be halted if reservoir reserves fall below critical thresholds.

Estimated water deficits

NTUA’s analysis indicates Attica is entering a period of hydrological risk. Annual deficits of 20–30 million m³ cannot be ruled out — equal to about 20–30 days of Athens’ water demand — raising the possibility of restrictions or short outages unless compensatory measures are taken.

Immediate measures

Short-term measures include reducing environmental outflow from the Evinos river, increasing water extraction from Yliki, and activating boreholes. Improvements to transmission channels, such as the Mornos aqueduct, are also urgent due to losses of around 10%.

Long-term infrastructure

Long-term solutions include reservoir reinforcements, partial diversions of the Karpenisiotis and Krikeliotis rivers (€500M Evrytos project), underground storage solutions, desalination technologies, reuse of treated water, and extensive upgrades to the network to reduce losses.

Water losses at 12%

The system loses 70 million m³ annually — about 12% of total abstraction — due to leaks and technical losses. EYDAP’s internal losses reach 15%. Reducing these leaks is critical for long-term stability.