Getting physical in Carshalton

After the success of our weir notching, river narrowinggravel introduction and bank planting it was time to turn our attention to instream habitat improvements.

Urban rivers often suffer from a lack of diversity of flow and bed structure.  They can be flat and uniform without many features.  The work that our volunteers undertook on 3 and 4 Sept is part of a series of events aimed at introducing some physical diversity and thus habitat diversity to the river. Different life stages of fish and invertebrates require different habitat, depth and flow conditions to survive.

Flow deflectors in the form of chestnut logs were used:

These were secured to the river bed using steel rebar.  This is important to make sure the deflectors stay in place and do not drift downstream in high flows.

Post rammers helped push the rods into the hard bed:

Tom Brake MP got stuck in and helped us to generate a few column inches in the process!

Putting the finishing touches to a deflector:

Clever arrangement of the deflectors creates channelling of the flow to promote scour pools, clean gravels and areas of faster and slower flow. Special thanks to Paul Gaskell from the Wild Trout Trust who joined us as a volunteer on Saturday and offered valuable advice and training in positioning the deflectors.

Rain didn’t stop our volunteers who stand proudly on a finished deflector!

With many thanks to all our volunteers: Alice, Bella, Derek, Erica, Gideon, James, Jez, Jo, John N, John P, Judith,  Malcolm, Mike, Paul, Sally, Theo and Tom.

This event was supported by the WATER project selected within the scope of the INTERREG IVA France (Channel) – England cross-border European cooperation programme, co-financed by the ERDF.

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