Urban planning helps mitigate extreme weather effects in Haut-Valais

Olivier Lalancette, an EPFL Master’s student in architecture, has come up with some development proposals for the Brig-Visp-Naters conurbation. His suggestions, relatively modest in scope, could help these cities better withstand the droughts and heavy rainfall that are expected to intensify by 2050. Lalancette hopes his study will start a conversation about the region’s future.

Switzerland is vulnerable to extreme weather events caused by climate change, now and in the future. MeteoSwiss has warned that if greenhouse gas emissions don’t fall by 2050, temperatures could rise by 1.8-3.3°C in winter and 2.3-4.4°C in summer. Mountain regions are expected to experience more dramatic temperature increases than other areas.

Rainfall over an average summer could decrease by 20% in the country, leading to long periods of drought like we saw this summer. In winter, precipitation could increase by 25%, yet snow will become increasingly rare.

Resilience and well-being

How can Swiss cities with a strong industrial past, impervious surfaces, and few public spaces be promptly remodeled so that they’re prepared for droughts and heavy rainfall? What role can architects play in land-use planning and risk prevention – areas which have, until now, been dealt with mainly by civil engineers? For his Master’s project, Lalancette identified two sites, both located in grasslands, where these challenges could be addressed. He uses the sites to show how urban areas can be made more livable by bringing together the various elements that the land has to offer.

Lalancette’s two sites are located in Haut-Valais: one in Brig and the other at a former Lonza disposal area. His suggestions are intended to make these areas more resilient and better suited to extreme weather events, while also improving public spaces and the well-being of the people living there. Lalancette spoke to several experts during his initial research – including Tony Arborino, the engineer behind the third Rhône River course correction, and the project managers for the Brig-Visp-Naters conurbation – to have better understanding of the context in which his ideas would be implemented.

Three changes in Brig

In Brig, Lalancette first suggests making the ground more permeable to rain by building a bioswale alongside a railway track to which trains will be redirected. This would create a runoff area for collecting water that could be infiltrated back into the soil and groundwater table. He also suggests covering a parking lot with trees and laying gravel on the ground, again with the aim of absorbing heavy rainfall. In a second phase, he recommends repurposing neighboring, partially empty buildings into community spaces.

According to Lalancette, part of the city center could be turned into an ecological corridor, which would better connect the city to agricultural areas. He notes that adding permaculture zones and trees would limit the heat-island effect and create a refuge for city dwellers during hot weather. In a residential area in the south of city, Lalancette recommends replacing asphalt with an absorbent material, and opening up several spaces to encourage residents to meet up with one another.

My suggestions show that improvements can be made. I’m hoping to start a conversation.

Ecological and pedestrian connections

What if one of Switzerland’s most contaminated sites was turned into a haven for biodiversity? With this idea in mind, Lalancette outlined possible redevelopment plans for a former landfill site in Gamsenried. The 290,000 m2 site that lies between Visp and Brig is currently being remediated by Lonza through a process that will take several decades.

Once the remediation work is complete, Lalancette suggests planting a range of heat-resistant tree species and adding pedestrian and bike routes to encourage people to cycle between Visp and Brig. “My ideas are still hypothetical since the land here is very complicated,” says Lalancette, a Quebecois who fell in love with the Alps. “But my suggestions show that improvements can be made. I’m hoping to start a conversation.”

Ski resorts become forests

His suggestions would require major renovation work to be done beforehand. And he warns that this may challenge the idea that a region’s identity is linked directly to its land. “Climate change will force us to repurpose some of the infrastructure that already exists in our regions,” he says.

In concrete terms, in order to slow down water flow and prevent soil erosion, city planners may need to plant trees at the bottom of disused ski slopes, renaturalize riverbeds and, in times of drought, use dam water for purposes other than power generation. “These are not controversial ideas in our industry, even if they seem like huge changes that will impact lots of people,” Lalancette says.

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