Restoring Nature May Offer Thessaly Hope in Mitigating Flooding

Flooding Thessaly

A helicopter evacuated a resident from a flooded village of Thessaly in September 2023. Credit: AMNA

The September 2023 flooding in Thessaly – Greece’s worst on record – washed away roads, homes, and farmland in the country’s breadbasket and left 17 people dead. Overall, Cyclone Daniel caused 3.5 billion euros in damage. It was the second major flood to hit Thessaly in three years, part of a trend of worsening extreme weather in Greece due to climate change.

By Evan Bourtis

For over 10 years, Thanos Giannakakis of the World Wildlife Fund Greece traveled the Greek islands to coordinate a project to conserve their wetlands.

He worked alongside communities, including in his home of Crete, to protect freshwater habitats that allow migratory birds, fish, and rare species to live surrounded by a saltwater sea. After that, he worked with organizations across nine nations to protect wetlands on every Mediterranean island.

Now, he’s working on a different but related project. He’s studying how restoring and protecting nature can make communities more resilient toward extreme weather, such as the devastating floods that hit the Thessaly region last year.

Giannakakis said officials have historically resorted to building dams to control flooding. Now some officials in Thessaly are exploring a different solution – giving rivers and lakes more room to rise without overflowing by restoring wetlands or other types of freshwater habitat.

“We are trying to change the perception of the public servants and the people,” Giannakakis said.

Wetlands act as a sponge that can absorb and slowly release water. They’re also among the most biologically diverse habitats on Earth, with an estimated 40 percent of all plant and animal species either living or breeding in wetlands, according to WWF.

One reason why Thessaly has become so vulnerable to flooding is because people drained wetlands to create more farmland in the 1940s and the 1970s. That’s according to a study published by WWF Greece and the Switzerland-based Global Infrastructure Basel Foundation. The study was in response to the 2020 flooding in Thessaly that killed three people.

Researchers explored ways the region’s riverside communities could become more resilient toward flooding and improve water quality using nature.

People being saved by rescuers in the recent catastrophic floods in Greece
Villagers evacuated from the floods. Credit: AMNA

Trikala in Thessaly looks to nature to adapt to flooding

One municipality in the region, Trikala, has already set aside nearly 7 million Euros in
funding for nature-based solutions as part of a flood resiliency plan.

Trikala – about 25 kilometers away from the Meteora monasteries – has three rivers
surrounding its city center and multiple villages. All three rivers flooded during the 2023
cyclone, impacting half of the municipality’s land and leaving people in two villages
standing on their roofs.

Harry Kalliaras, advisor to the mayor of Trikala, said military members rode boats into
the villages to rescue the residents surrounded by over two meters of water. From there, the military took them into the city, where they stayed in either hotels or an indoor
sports arena for a month. No one died during the flooding in Trikala but 281 homes had to be demolished.

Kalliaras said touring the flooding damage was like seeing a war zone, with torn-up
farmland, roads, and electricity networks. “You can see cars and equipment everywhere,” he described.

According to the WWF Greece study, people altered the path of one of the municipality’s rivers – the Lithaios – decades ago for irrigation. That made the river narrower and caused an 8-kilometer stream to dry up. What’s more, the municipality’s Pineios River and Agiamonioris River have lost some of their wetlands since the 1940s because of human activities.

All those things have left fewer places for water to drain at a time when storms are
becoming more intense and frequent.

As a remedy, the study suggests widening the dried-up, 32-kilometer-long riverbed of
the Lithaios so it connects to the river’s modern-day path. The study also recommends
restoring wetlands in four spots where they once existed in Trikala, hoping to shield
flood-prone villages.

When officials in Trikala adopted an urban development plan for flood protection, with a
total budget of 12.5 million Euros, they set aside 55 percent of that money for nature-based solutions.

The plan will take place through 2029. While preparing the plan, officials spoke with
members of the public for more than four months to design projects to fit their needs.
“It’s essential to see the local society as equal to you in order to make a plan. You have
to find out how they can trust you,” Kalliaras said.

Flooding Thessaly
A resident escapes the flooding on a boat last September. Credit: AMNA

Climate change is exposing failures

Giannakakis said that nature-based solutions are critical in places, like Trikala, where
there is a disconnect between the rivers and their floodplains.

He said climate change is exposing decades of failures in communities when it comes
to land use and the design of bridges, roads, and other infrastructure. During the 2023
flooding, the road network at Mt. Pelion was destroyed, trapping thousands of people in
villages and tourists resorts.

“Climate change shows you what are the things you have done wrong,” he said.
Kalliaras said nature-based solutions may become part of Trikala’s legacy of using
innovative solutions to overcome challenges. The city’s network of sensors – which
collect data on services including parking spaces, water pipes, garbage trucks, and
traffic lights – earned Trikala the title of Greece’s first ever smart city. Trikala also
became the first European city to use fully-automated droids to deliver items.

The city’s sensors inside its river helped to foresee the flooding, according to Kalliaras.
Now, he’s hoping that nature can offer a cost-effective solution for Trikala and other
cities to mitigate flooding and other impacts of climate change.

“I think that we will see, in the very close future, these kinds of solutions instead of the
previous considerations of dams or big water tanks,” Kalliaras said.

Trikala has already undertaken at least one nature-based project. Since the massive
flooding in 2020, they’ve cleared debris from rivers to give them more room to rise.

Giannakakis said there are other benefits to protecting and restoring nature besides
adapting to climate change. In Crete, wetlands provide a home for the Cretan Frog – a
species found only on Crete and nowhere else. Similarly, the Gizani fish is found only
on the wetlands and rivers of Rhodes.

Greece’s wetlands, particularly on the islands, are home to a variety of rare species. Destroying wetlands in just one small area could not only make a community more vulnerable to flooding but could mean losing a species forever.

By mapping out hundreds of wetland sites across 75 Aegean and Ionian islands, WWF
Greece has stopped the degradation of over 100 wetlands. The agency has also
educated local authorities about the risks that wetlands are facing and how to protect
them.

“We are expecting worse flood events so we cannot go the way we used to go,” he said.

Related: Reconstruction After Floods in Thessaly, Greece to Cost €3.5 Billion