Brest is a coastal city on the western tip of France. Being in a small, urbanised catchment, the city is vulnerable to sudden flooding and combined sewer overflows caused by heavy rainfall. Climate change and an increase in soil sealing are making these events more likely. Since 2016, new stormwater service regulations promote the use of measures like nature-based solutions to store rainwater and allow it to can soak into the ground. This reduces the risk of flooding and minimises the pollution of waterbodies from combined sewer overflows.

Brest’s two pilot projects test how nature-based solutions can manage stormwater. The Kertatupage project is a park that can flood, with an underground water storage basin underneath. The park also provides biodiversity-friendly planting and new pathways and shelters for people. The Keravelloc project involves daylighting a small stream (bringing it back up from underground) and renovating the surrounding park to provide more space for floodwater and to encourage recreation and nature.

As part of GrowGreen, Brest Metropole is assessing climate change challenges in the territory to develop a strategy for using nature-based solutions to tackle them. It will also explore new options for financing nature-based solutions and their maintenance.

Objectives: Expected impacts:
• To better understand how climate change will affect the territory to inform the development of a nature-based solutions strategy. • An enhanced understanding of climate change impacts on the territory of Brest.
• To identify innovative ways to meet the citizens’ increased demand for green spaces with the currently available resources. • A new strategic approach for nature-based solutions in Brest.
• To use pilot projects to test how nature-based solutions can manage stormwater and provide co-benefits in Brest. • Reduced flood risk and greater biodiversity and recreational access at the pilot projects.

Key outcomes / results

• The River Spernot was daylighted in 2019, with an expanded area to allow it to flood, in the Jardin de Keravelloc. The park also includes new paths and play spaces.
• Major groundworks for the Kertatupage Park were completed in spring 2019. New pathways, a bridge, and biodiversity spaces will be implemented in autumn 2020 and spring 2021.
• Public awareness raising campaigns on stormwater management and the importance of nature-based solutions for increasing stormwater infiltration have been completed.
• The public, including school children, contributed to the daylighting of the River Spernot.
• Studies of the public’s perception of nature in the city, and scenarios of sea level rise and stormwater flooding with climate change have been completed.
• Further analyses and assessments of the impact of climate change, as well as of the current policy framework, are continuing.