Rising Waters in Venice: a preview of coastal cities around the world

by Mandy Ikert, C40’s Head of Adaptation Implementation

On October 29th, Venice was submerged under 156 cm (just over 5 feet) of high tide or “aqua alta”, flooding three-quarters of the city including public thoroughfares and landmarks including the famous St. Mark’s Basilica, closing schools and public transportation and challenging the runners of the historic Venice marathon. 

Just days before, 10 member cities of the C40 Cities Connecting Delta Cities (CDC) network gathered in Venice to discuss techniques to prepare for and manage flooding events such as these – which are becoming increasingly common around the world due to climate change. According to The Future We Don’t Want, a C40 report released earlier this year, more than 570 coastal cities are at risk of at least half a meter of sea level rise and related coastal flooding.

“The visit of delegates from 10 cities coming from all over the world was an amazing opportunity to discuss climate change adaptation of coastal cities and we are very happy to be able to showcase the actions Venice is putting into practice to limit the impact of flooding, cloudbursts, heavy rainfall and tide surge. We have realized that from a technical point of view every city has its specializations but that the difficulties in delivering comprehensive climate change adaptation are the same at all latitudes. This encourages us and strengthens even more in the action, especially as we draw inspiration as we begin to draft the Venice Climate Action Plan to ensure that Venice is prepared for the future.”

Massimiliano de Martin, Venice Deputy Mayor

Venice’s experience is shared by the cities that attended the CDC workshop; each of them are experiencing extreme weather events, increasing in frequency and fortitude, due to the effects of our warming planet. The flood in Venice took place on the 6th anniversary of Hurricane Sandy in New York, but a mere month after Typhoon Mangkhut clipped Hong Kong, and Hurricane Florence narrowly skirted Washington DC. Tokyo is already preparing for the super-typhoons of the future, which are more likely to have a direct path to their downtown area, and Rio de Janeiro has experienced recent aberrant wave action wiping out coastal infrastructure.  Copenhagen has also experienced year after year of extreme storms. 

The CDC gathering of key policy-makers from around the world is also timely given recent increased projections of severe coastal flooding, which is expected to double in frequency according to a study published last year in the Scientific Reports journal. Globally, natural disasters such as these cost over US$ 500 billion every year, with current average losses attributed to climate change hazards in Europe estimated at 13.3 billion Euro per year.

“It is hard to imagine a better city and timing to hold a Connecting Delta Cities Workshop than late October in Venice. We could see the city’s long experience in dealing with extreme sea level being put to test, and also learn about further actions that are being implemented and planned to enhance the island’s resilience to an already observed increase in frequency and intensity of flooding.”

Felipe Mandarino, Rio de Janeiro

During the 3-day workshop, participants focused on the changing climate conditions experienced by cities around the world, mapping and modeling compounded climate hazard events, communicating risk and vulnerabilities to citizens, collaboration with other agencies and other key urban stakeholders, and sharing strategy and experience in coastal protection and related flood management.

“Engaging with other global delta cities on the increasing risk of coastal flooding due to rising sea levels brought home to us the very real threats and challenges we face together,” said Phetmano Phannavong, DC Floodplain Manager at the District of Columbia Department of Energy and Environment. “Our continued cooperation will help Washington, DC adapt to climate change in innovative and vital ways.”

Venice is an innovator city within the C40, sharing its centuries-long experience living with water both through engineered and nature-based solutions. After visiting several site around the city, CDC members recognized that an integrated system like Venice’s – including engineered solutions, nature-based solutions and a clear system of information management and risk communication – is crucial to ensuring that our cities can manage the effects of sea level rise and the more intense weather patterns to come. As Realdania representative Mikkel Suell Henriques noted: “Resilience is more than just putting a wall at the end of the ocean.”