Silt traps installed to protect the Wensum

 

We are working with farmers, businesses and local communities to reduce the agricultural pollution that affects East Anglia’s precious chalk streams. One of these farms we are working with is the Salle Estate in the Broadland Rivers catchment, which covers 2000 hectares.

For a decade the farm has been trialling different methods to reduce the impact of agricultural pollution on local rivers – such as relocating gateways and rainwater harvesting. Working with the University of East Anglia and Norfolk Rivers Internal Drainage Board, we identified a site that was contributing to the run off entering the Blackwater Tributary which feeds the Wensum Special Area of Conservation (SAC). To prevent this silt eventually entering the Wensum, three silt traps have been installed which have been part-funded by Coca-Cola as part of the project. You can find out more about how Coca-Cola are involved here.

Silt trap locationsSalle Sediment Trap Areas © Norfolk Rivers Trust

Salle Sediment Trap Areas © Norfolk Rivers Internal Drainage Board

How will this help?

This is good for the river as excess sediment and nutrients disrupt the ecosystem by blocking light, contributing to eutrophication and impacting upon the wildlife that relies on the river for survival. It is also good for the farm as those nutrients will remain on the land and enrich the soils instead of running off into the water course.

The sediment that is caught sits in the bottom of the trap until it is emptied every few years and put back on the fields, returning the nutrients to the soils.

As the site is within the University of East Anglia Demonstration Test Catchment area, they have and will continue to monitor the water quality. This will enable us to assess and evaluate exactly how the trap performs and the impact it has on the health of the river.

 

Silt trap being installed on the Salle Estate © Norfolk Rivers Trust
Silt trap being installed on the Salle Estate © Norfolk Rivers Internal Drainage Board

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