The idea
The Challenge
Athens is now among the most vulnerable European cities facing the climate crisis. A Moody’s report (2023) ranked it first in risk from heatwaves and drought, while the “Kleon” heatwave (July 2023) raised the temperature to 45°C, confirming that extreme events are becoming increasingly frequent and intense.
More than 80% of the urban fabric is covered by impermeable materials, which trap heat and enhance the urban heat island phenomenon. At the same time, the complete absence of surface water flows—as the city’s three historic rivers have been buried under asphalt and concrete—deprives residents of a natural means of cooling and worsens the problem.
Current solutions, such as limiting outdoor work during the hottest hours, remain fragmented and short-term, leaving the most vulnerable households without adequate and quality public cooling spaces.
The Vision
Cooling Havens brings water and greenery back to Athens through a network of 6 Cooling Points. It includes urban interventions, such as rainwater collection gardens, bioswales and gardens irrigated with reclaimed water through sewer mining technology. All solutions emerge from an open architectural competition.
The installations create more than 8,000 m² of new blue and green infrastructure and aim for approximately 2-5°C reduction in local temperature during heatwave days, while retaining more than approximately 70% of intense rainfall.
Each Point is equipped with “smart” IoT sensors for temperature, humidity and water consumption, which collect and transmit real-time data to a Open Data portal, allowing the city—and citizens—to monitor performance and optimize their operation.
The interventions are implemented in six key areas of Athens:
• Ilisos Park, Ilisia
• Ag. Lavras Green Space (ISAP Station), Ano Patisia
• Lakonia Square, Ampelokipoi
Ramnes Square, Kolonos/Metaxourgeio
Ag. Nikolaou Pefkakion Park, Neapoli Exarcheia
Fokionos Negri, Kypseli
The solution
The solution is framed by a comprehensive participation and learning program:
Athens Water School & Digital Water Memory Lab
Educational pathways and storytelling workshops around water.
Citizen Participation Centers
At least 5 co-design workshops per neighborhood, aiming for the participation of over 120 residents in the design.
Green Jobs & Municipal Staff Training
Training 40 unemployed people in the maintenance of water and green-based infrastructures, as well as 25 municipal employees in resilient design.
Open Public Data Lab for sustainable water management
Where citizens, researchers and organizations have access to live measurements and information, so they can monitor, understand and improve water use in the city.
Data visualization and multimedia artworks
Artists, data scientists and environmental experts collaborate to transform environmental data into visually captivating representations, making information accessible and understandable to all audiences.
This approach creates cooling points and cultivates a culture of responsible water use in every neighbourhood, while strengthening participation and citizens’ sense of collective responsibility for public space and the environment.
The Innovation
The innovation of Cooling Havens begins at Ilisia Park, where water recovery system technology (sewer mining) for irrigation is applied: a water recovery system that provides clean, reclaimed water for irrigation and creates a new water garden. This solution, combined with rainwater gardens and bioswales, shows how the city can utilize its natural resources in a smart and sustainable way.
The Cooling Points of Cooling Havens are not simply technical infrastructures; they constitute participatory platforms that combine innovative design, cutting-edge technology and cultural creation.
Integrated water management technology & low cost
Two mobile, relocatable structures show that economically affordable solutions can measurably reduce temperature and be extended to other neighbourhoods.
Smart microclimate monitoring
25 data collection stations and IoT sensors measure temperature, humidity, water consumption and air quality. All data is published on an Open Data Portal, accessible by the city and citizens.
Optimization with artificial intelligence
AI algorithms analyze data in real time and regulate water and energy flows, reducing the environmental footprint.
Data becomes art
Interactive multimedia installations transform climate data into visual experiences, engaging the public and enhancing experiential learning around water.
Co-creation ecosystem
From the Athens Water School to the Open Design Competition, the project invites students, artists, technicians and municipal employees to co-design, maintain and extend the interventions, creating a new water culture in the city.
The result is a first and innovative integrated solution for Europe that combines the integration of water in public space, digital governance and social innovation – a solution ready to be replicated in other cities with similar challenges.
European Urban Initiative (EUI)
Cooling Havens is implemented thanks to co-financing from the European Urban Initiative (EUI)—the successor mechanism to UIA that supports bold, transformative solutions in European cities.