EYDAP S.A.

About the Utility

EYDAP holds the exclusive right under Greek law to provide water supply and sewerage services in its area of competence, and it has also taken over the municipal networks of Megara. Its operating framework is a contract between the Greek State, the EYDAP Asset Company and EYDAP itself, signed in February 2022 and valid until 2040. The Greek State directly and indirectly controls 61.33% of the voting rights. Water supply reaches approximately 4,400,000 residents, more than its sewerage network serves. The Waste, Energy and Water Regulatory Authority has confirmed the company's management adequacy as a water services provider and now approves its tariffs.

Water System

All the water EYDAP sourced in 2021 came from surface waters. Under an operation and maintenance contract it also runs the External Water Supply System, which is owned by EYDAP Fixed Assets, while four treatment plants feed approximately 14,300 kilometres of distribution mains. Losses, rather than demand, are the central operating constraint: non-revenue water was calculated at 23.70% in 2023. In 2025, as invoiced consumption edged down, the company replaced approximately 98 km of secondary and tertiary mains and repaired 25,546 emergency damages on a network it describes as outdated.

Wastewater System

Sewerage is a full part of EYDAP's remit, delivered through a network of approximately 8,716 kilometres. Treatment is concentrated at the Psyttalia wastewater treatment plant, which has an average design flow of one million m³ a day against an average incoming flow of around 650,000 m³ a day. Storms test the system: flooding caused overflows of 2,021,222 m³ in 2022. The company reported no breaches of effluent quality permits, standards or regulations in 2023. Works in East Attica, first described as sewerage and water recycling projects, are the largest item in successive ten-year plans.

Investment & Priorities

EYDAP's investment programme is set out as an accelerated ten-year plan of €2.5 billion, which is a plan rather than committed spending. Delivery now centres on loss reduction: approximately two million smart meters are being installed, against a strategic goal of reducing losses to 8–9% by 2029. Pricing runs through a regulated asset base framework, under which the regulator approved allowed revenue for the first regulatory period on a WACC of 6.24%. It refused to let EYDAP recover €323 million of earlier costs, a decision the company disputes.

Sustainability & Resilience

Water scarcity has become the dominant resilience issue. Attica was placed in a state of emergency because of water shortages in November 2025, for six months. EYDAP states that its actions as operator of the External Water Supply System, together with EYDAP Fixed Assets, will add 150 million cubic metres a year to the Athens supply system, a stated effect rather than a delivered volume. Renewable sources provided 73.47% of total energy consumption in 2025. Financially, the company carries no loan obligations.

Key Challenges

1. Securing supply for Attica after the water-shortage emergency declared in November 2025.
2. Reducing losses on an outdated network toward the company's 8–9% goal for 2029.
3. Delivering the accelerated €2.5 billion ten-year investment plan, including East Attica works.
4. Financing the programme while €323 million of prior-period claims remain disputed.
5. Containing flood-driven wastewater overflows during storms.

Major Projects