Running dry, then underwater: Greece’s path to building resilience against climate threats

Greece is caught in a climate trap: Longer droughts are now precursors to more intense floods, a dangerous cycle driven by parched landscapes and overwhelmed waterways. 

Scientists possess the technical know-how to break this chain with strategies such as early warning systems and nature-based solutions, but there is a problem.

The EU’s recent legal action against Athens for lagging flood preparedness reveals a hurdle: Political inertia hindering the shift from reactive disaster response to proactive, resilient planning crucial for safeguarding the nation against escalating climate risks.

Climate change is having widespread effects, including on the water cycle, which in turn directly impacts events like droughts and floods. Scientists often refer to this interconnectedness as the “climate change–drought–flood” chain, or as a set of compound risks.

Future climate projections, based on mathematical models known as Global and Regional Circulation Models (GCM and RCM), generally predict rising temperatures and changing rainfall patterns, often with fewer but more intense rain events. In many areas, this leads to drought conditions that can last for months.

Rainfall and drought interplay

Ironically, these prolonged dry spells can actually set the stage for severe flooding for three main reasons.

First, extended droughts cause soil to dry out and become more compact, reducing its ability to absorb water. In extreme cases, the soil can even become hydrophobic, repelling water rather than soaking it up. So when heavy rain eventually comes, much of it runs off the surface rather than being absorbed, increasing the risk of sudden floods.

Second, droughts weaken or kill plants that would normally stabilise the soil and help retain water. Without this natural buffer, rainwater flows more quickly across the landscape, accelerating run-off and erosion.

Third, reduced river flow during droughts can lead to sediment building up in streams and riverbeds, effectively clogging them. When the rain does return, this blockage increases the likelihood of overflowing and flooding.

What matters, then, is how much water arrives and how suddenly, in these drought-altered conditions. Droughts also affect rainfall characteristics. Warmer air holds more moisture (about 7 per cent more per degree of global warming), so when that moisture eventually condenses, it can lead to intense rainfall.

Meanwhile, higher evaporation rates during dry periods mean that when rain does fall, it often comes in short, violent bursts that overwhelm drainage systems. So, when a sudden downpour hits dry ground with sparse vegetation and sediment-choked rivers, the landscape simply cannot handle it, leading to destructive flash floods.

We have seen this in recent years in places like California, Australia, Central Europe, the Mediterranean, and Greece (including Thessaly and Central Greece). For the scientific community, these are not surprising events. In fact, many of us have contributed to studies forecasting such occurrences.

Strategies for risk reduction

The key challenge now is how to build resilience and protection based on what we already know. Here are some basic strategies to help manage and reduce flood risks.

First, Early Warning Systems (EWS) are crucial. It is now possible to predict sudden floods days in advance, which allows for timely prevention and response.

The role of intermittent rivers and streams is key for dry areas. These waterways remain dry most of the time but flood after heavy rain. Without accurate mapping (an overlooked topic in many countries) showing where they are and how much water they can carry, it is nearly impossible to design effective flood defences. Infrastructure planning and land use are very important.

Measures such as moving levees further away from rivers, allowing natural floodplains to absorb overflow, or deepening riverbeds to increase their flowing capacity, along with sustainable land-use practices such as reforestation and sustainable farming that help the soil absorb water and reduce run-off are key. It is also critical to stop building on flood-prone land near rivers, a practice still common in Greece.

Drainage and irrigation upgrades are crucial interventions. Maintaining and modernising dikes, canals, and irrigation systems can help regulate water flow during both droughts and floods.

The climate is changing and we have to adapt to more extreme rainfalls. In Greece specifically, this means rethinking how we design flood, drainage, and even road infrastructure. Simply rebuilding what existed before a flood is not enough. Those older designs were based on rainfall patterns from decades ago, which no longer apply. That is why we keep seeing repeated failures in the same places.

Nature-Based Solutions (NBS) can also help in sustainable ways with multiple co-benefits. These include smaller-scale, ‘smart’ projects like restoring riverbanks and floodplains, reconnecting rivers to their natural flood zones, and planting vegetation to slow down run-off. Removing man-made barriers that disrupt river flow, creating wetlands to reduce peak water flow, and using urban sustainable drainage systems (SuDS) help.

The implementation gap

These ideas are not new, but they align with national flood and drought risk management plans. Much of this is already included in our own research and in many other studies we often cite.

The problem is that in most cases, policymakers have not implemented such plans adequately. Greece was brought before the European Commission’s Court of Justice in 2024 for failure to finalise the revision of its river basin management plans as required under the Water Framework Directive 2000/60/EC and of its flood risk management plans as required under the Floods Directive 2007/60/EC. As a result, we see the same areas getting hit again when new disasters strike.

Our analyses show that flood protection using small-scale, local interventions might cost even a fifth of the damages that a flood might cause.

Experience has shown that with the right interventions, we can avoid the worst impacts of climate change, many of which are already well understood. These resilience-building projects also create local jobs and can be funded through European programmes that Greece is eligible for, but often fails to absorb.

So perhaps the most urgent issue is not technical, but political. We may need a shift in mindset and behaviour at the level of governance — a move away from reactive rebuilding, and toward proactive, resilient planning in the face of compound climate risks.

Dr. Phoebe Koundouri is a Professor at the Athens University of Economics and Business and the Technical University of Denmark. She is the President of the World Council of Environmental and Natural Resource Economists Associations, Chair of the SDSN Global Climate Hub, Director of AE4RIA, and Director of the Sustainable Development Unit at ATHENA Research Center.

Dr. Angelos Alamanos is an independent researcher based in Berlin, Germany.

Originally published under Creative Commons by 360info™.