Valenciennes Métropole chooses Hydro International' s Downstream Defender Select
Downstream Defender® Select chosen to protect the Rhônelle River in France
Valenciennes Métropole in France chooses Hydro International's new generation of hydrodynamic vortex separation technology; delivered in partnership with Stradal; to protect the Rhônelle River.
Context
The quality of stormwater runoff has become a critical issue for protecting aquatic environments and safeguarding water resources, especially in communities facing growing urbanisation and the impacts of climate change.
Urbanisation and climate change are increasing the pressure on stormwater networks across France. Valenciennes Métropole faced recurring overloads of its combined sewer system during heavy rainfall, leading to polluted overflows into the Rhônelle River. The community launched a major project in Marly (59) to improve the quality of stormwater discharges and reinforce long‑term environmental protection.
Hydro International's Solution, Delivered in partnership with Stradal
To support the municipality’s sustainable stormwater strategy, two Hydro hydrodynamic separators were installed on the newly disconnected stormwater network.
Assembled locally by Stradal, Hydro’s long‑standing partner in France, these units provide high‑performance treatment for runoff before it reaches the natural environment.
Image source Stradal
Performance Highlights
- Treatment capacity: up to 750 L/s
- Pollutant capture: macrolitter, suspended solids, and micropollutants
- Fine particle removal: down to 63 microns (approx. the diameter of a human hair)
- Outcome: significantly improved water quality discharged into the Rhônelle
This level of treatment ensures robust protection of the receiving environment and supports the community’s ecological commitments.
Image source Stradal
Supporting Sustainable Urban Development
Beyond technical performance, the project demonstrates how municipalities can reconcile urban development with environmental protection. By disconnecting networks and treating stormwater at the source, Valenciennes Métropole strengthens biodiversity, improves river health, and builds resilience to climate change.
As Jérôme Bourgoin, Head of Water and Sanitation at Valenciennes Métropole, emphasises: It is vital to reinfiltrate clean water into our rivers to preserve our water resources.
Image source Stradal
A Partnership That Delivers
This project illustrates the strength of the Hydro International and Stradal partnership in France:
- Hydro International provides proven, internationally recognised stormwater treatment technology
- Stradal ensures local manufacturing, availability, and technical support
- Municipalities benefit from a complete, reliable, and high‑performance solution
Want to know more?
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