Multifunctional water management and green infrastructure development in an eco-district in Rouen

Rouen, in France's Atlantic region, faces increased heavy-precipitation/river-flood risk and an intensified urban heat island, both projected to worsen under climate change. The former industrial Luciline site along the Seine was redeveloped into a 9-hectare mixed-use eco-district, a complex project given its scale and the number of stakeholders involved.

The project aimed to redevelop the former industrial site into a sustainable neighbourhood covering residential, office and commercial uses, built around integrated water management, renewable energy, sustainable mobility and green space, targeting the official French 'Ecodistrict' label and 'Ville de Demain - Ecocité' status.

A canal-based drainage system connects to the Seine via vegetated ditches; roughly 3 hectares (about 30% of the site) became green public space; buildings use green roofs; a district heating/cooling network draws relatively warm/cold water from the Seine (targeting 60% of heat supply) backed by gas boilers; 25 km of pedestrian/slow-traffic paths and three fast public-transport lines were built; the first passive building was delivered in 2014.

Total project cost is about EUR 50 million, including the city of Rouen's EUR 28 million investment, a EUR 25 million European Investment Bank loan, roughly EUR 2 million in European/national subsidies (including EUR 0.6 million from the INTERREG 'Future Cities' programme), and a EUR 5 million heating/cooling system (net EUR 2.5 million after subsidies/prepayments).

Strong political and financial commitment from the city, layered EU/national subsidies, international peer exchange via INTERREG Future Cities (with Nijmegen and Arnhem), and an ongoing monitoring/evaluation programme for adaptive management were cited as success factors. Negotiating agreements with existing landowners and companies caused time overruns; full completion is expected by 2030.