Basse Saâne 2050: where do we go from here?

Ambitious and innovative. The territorial project shapes the future layout of the lower valley.

What will the Lower Saâne Valley look like in 2050? This question emerged in the 2000s, when storms, river and coastal flooding became more frequent and severe. It then became clear that the effects of climate change would not spare the area and that sea level rise would destroy any confidence in feeling safe behind the dyke erected in 1914 “to protect [the valley] from being inundated by spring tides and to rid it of the feverish miasmas that have too often been the cause of epidemics”. If, for a hundred years, the dyke has valiantly fulfilled its mission, its limitations and side effects are becoming problematic: for example when increasingly frequent rainfall upstream causes the Saâne River to swell and burst its banks, the dyke prevents fast drainage of the water into the sea. The lower valley then acts like a bathtub with too narrow a plughole: impossible to drain.

Should we turn back the clock and remove the dyke? The idea has been considered. But the area is no longer what it was in 1864, when the first culvert was laid. Amenities have been built behind the dyke: the departmental road, the Quiberville municipal campsite, houses, economic activities, etc.

Gradually, decisions have been made: the lower Saâne valley chose to take advantage of the inevitable adaptations needed for the new conditions to re-shape its future, its economic development and its living environment. The local stakeholders (State, Region, Department, intercommunalities, municipalities, associations, local residents, farmers, fishermen, hunters, water agency, etc.) engaged in a phase of intense consultation that led to the design of the Lower Saâne 2050 territorial project, whose coordination was entrusted to the Conservatoire du littoral with three objectives:

  • to deal with the risk of flooding by encouraging the flow of the Saâne to the sea while responding to the risk of marine submersion;
  • to improve the quality of the environment and restore biodiversity; and
  • to take into account all the socio-economic uses of the lower valley (residents, users, farmers, fishermen, hunters, tourists, etc.).

To achieve this, several project strands had to be launched. To limit the risk of flooding, the Saâne must be reconnected to the sea, while preserving the dyke and the coastal road: a rigid-frame bridge will see to this. The river must also be given space to overflow when in spate. But its floodplain is already partly occupied by… the Quiberville campsite. Prone to both river and coastal flooding, the campsite was at a constant risk of being closed down by decision of the Prefecture. It therefore had to be moved. Today, the land on which the future tourist facilities will be built has been serviced and construction work is almost complete. In order to improve the quality of the water discharged into the sea, the ecological and sanitary condition of the Sâane must also be boosted. This means improving the quality of the water discharged into it. This will be ensured by the wastewater treatment plant in Longueil, whose construction is nearing completion, and connecting up those houses not currently connected to the collective sewer network.

When completed, all of this work will mean that the Sâane will get back its floodplain in which to meander before flowing into the Channel under its brand new rigid-frame bridge. Of course, all this must be financed. But the Lower Saâne 2050 project has been able to benefit from EU funding through the cross-border PACCo (Promoting Adaptation to Changing Coasts) project between the Lower Saâne valley and, on the English side, the Lower Otter valley. The Lower Sâane valley will be given a new look, thus enabling the newly laid-out area to meet the challenges of the 21st century.

The three initiatives are:

Relocation of municipal economic activity with the construction of the new Quiberville tourist facilities
• Contracting authority: municipality of Quiberville
• Project cost: €8.6m
• ERDF amount:  €5.9 m
• Work completion: June 2023

The new Longueil wastewater treatment plant and connection to the sewage networks
• Contracting authority: Terroir de Caux Community of municipalities
• Project cost: €22.8m
• Part financed by the Interreg PACCo project: €4m
• ERDF amount: €2.8m
• Work completion: March 2023 (PACCo) or end of 2024 (whole project)

Re-meandering of the Sâane and reconnection to the sea
• Contracting authority: Syndicat mixte des bassins versants Saâne, Vienne et Scie
• Budget: under consideration
• Funding: Seine-Normandy Water Agency, Syndicat mixte des bassins versants Saâne, Vienne et Scie
• Work completion: 2025

Funding breakdown:
• Normandy Region 6 %
• Department of Seine-Maritime 5 %
• Municipality of Quiberville 20 %
• ERDF (EU funding) 69% Financing split of the PACCo work phase:
• Department of Seine-Maritime 5 %
• Terroir de Caux Community of municipalities 15 %
• Seine-Normandy water agency 11 %
• ERDF (EU funding) 69%

“The contribution of the Seine-Normandy Water Agency to the Lower Saâne 2050 project is both technical and financial. Firstly, as regards the reconnection of the Saâne River to the sea, our objective is to contribute to the preservation of biodiversity, particularly migratory fish, but also all the fauna and flora of the lower valley: birds, insects and amphibians. Secondly, as regards sanitation, we are supporting the Terroir de Caux Community of Municipalities in its project to build a wastewater treatment plant and to divert the domestic wastewater that used to flow directly into the Saâne. The aim is to preserve the quality of the river’s water as well as the quality of bathing water.”
Delphine Jacono, Aquatic and Wetlands Project Manager at the Seine-Normandy Water Agency, “The contribution of the Seine-Normandy Water Agency to the Lower Saâne 2050 project is both technical and financial. Firstly, as regards the reconnection of the Saâne River to the sea, our objective is to contribute to the preservation of biodiversity, particularly migratory fish, but also all the fauna and flora of the lower valley: birds, insects, amphibians. Secondly, as regards sanitation, we are supporting the Terroir de Caux Community of Municipalities in its project to build a wastewater treatment plant and to divert the domestic wastewater that used to flow directly into the Saâne. The aim is to preserve the quality of the river’s water as well as the quality of bathing water.”
Delphine Jacono, Aquatic and Wetlands Project Manager at the Seine-Normandy Water Agency

“When floods produce disasters somewhere in the world, this affects us for 48 hours, and then we move on. “It won’t happen here”. And why shouldn’t it happen here? This is a natural reaction, as we can’t live with permanent anxiety. But we have to learn to live with this risk! One part of the population is particularly sensitive to this risk, and these are young people and schoolchildren. They obviously look to the future more than we do, to 2050 or 2100! They are more sensitive to environmental events: they were born with them! I’m convinced that we need to rely on them and help them… educate their parents!”
Nicolas Leforestier, President of the Syndicat mixte des bassins versants, Saâne-Vienne-Scie

“From the very first project meetings, I was amazed to see that everyone was present: the mayors, the department, the water agency, the State agencies… And of course the Conservatoire du littoral. Each meeting was attended by 45 people! The key to this project’s success was collective intelligence: people know each other, discuss things with each other, and they could see, on a daily basis, that the situation was not sustainable, that the Quiberville campsite was being eaten away by the sea. The whole point of this project – and also the difficulty – was to ecologically restore an area, but without turning it into a shrine.”
Hubert Dejean de la Batie, Vice-President of the Normandy Regional Council and Former President of the Conservatoire du littoral

“What the Lower Saâne 2050 project demonstrates is that it is only by bringing together all the players that significant changes can be made. Of course, this takes a long time: it took almost ten years of consultation for the project to become a reality. But we have to understand what these changes represent: a tangible impact, obviously, but also and perhaps above all a cultural impact for local people. What has changed is not only the landscape, but also its uses. It is illusory to think that this can be achieved by putting a gun to people’s heads. It is a question of method, of prioritising the issues, and of becoming aware of our collective responsibility.”
Bertrand Bellanger, President of the Seine-Maritime Departmental Council

“There are a number of tourist and agricultural activities in the valley, what will happen to them if we do nothing? We took the time to share this observation with all the players, and this time was also put to good use to get to know each other, to build trust, and to convince everyone that we had no hidden agenda. It was also the time it took to get everyone around the table. The other factor of success is the continuous groundwork that project managers carry out every day. We need people who can show empathy and understanding, who can pick up the phone to solve a problem without waiting for the next big meeting. This low-key work is absolutely necessary”.
Jean-Philippe Lacoste, Normandy delegate at Conservatoire du littoral