Water quality on the Hampshire Avon is set to improve thanks to a successful partnership between the Environment Agency, Wiltshire Council and a local landowner

The Avon is one of the UK’s top salmon rivers, but in recent years has suffered from sediment pollution – a major source being poorly-maintained farm tracks that discharge silt straight into local watercourses. Once in a river, sediment can harm the spawning grounds of salmon and trout. The run-off can also deliver pollutants that contribute to nutrient enrichment and upset the river ecology.

One of the worst affected areas was a farm track at Berwick St James where sediment was regularly washed into the River Till, a tributary of the River Wylye that flows into the Avon. The pollution turned the river a chalky white.

This stretch of the Hampshire Avon is a Site of Special Scientific Interest (SSSI), a Special Area of Conservation (SAC) and is important for fish spawning. Contamination caused by the agricultural run-off resulted in Natural England downgrading the SSSI to an ‘unfavourable condition'.

The badly-eroded track at Berwick St James is a Right of Way that provides access to a local farm. It extends for two kilometres and belongs to Berwick Down Ltd. Over the years the sunken track eroded below the level of surrounding fields and became a huge drainage gully.

The problem has now been solved thanks to the combined efforts of the Environment Agency, Wiltshire Council and the landowner who have carried out improvements to prevent sediment being washed straight down the farm track into the river.

Run-off is diverted from the track into surrounding fields using existing ditches that have been dug out. A newly-installed drain carries run-off into a sediment pond where silt from the track and surrounding fields is captured. The track has also been re-surfaced and cambered to control the direction of flow.

The improvements at Berwick St James were funded by the Agency and carried out by Wiltshire Council contractors as part of a Catchment Sensitive Farming Initiative.

Catchment Sensitive Farming aims to reduce diffuse water pollution from agriculture with the help of farmers and landowners. The Hampshire Avon is one of 50 catchments across England where the river environment is being improved through a working partnership with the Environment Agency and Natural England supported by Defra.

"The River Till is one of the most important tributaries on the Hampshire Avon. Previously we had a problem with large amounts of sediment-laden water entering a sensitive river system and harming the environment. Now, thanks the farm track improvements we’ll see a corresponding improvement in the SSSI which is great news," said Ellie Mantell, Catchment Sensitive Farming Officer for the Hampshire Avon.

The improvements have been welcomed by local anglers. "All of us who care about the River Till and Lower Wylye are very grateful to the Environment Agency, Wiltshire Council and Berwick Down Ltd for the way they diagnosed and resolved this pollution problem as part of a Catchment Sensitive Farming Initiative. We are impressed by how well they worked together," said Peter Hayes, President of the Till Fly Fishers Association

"This project has significantly reduced the amount of sediment entering the river. The future now looks much more positive for our salmon and trout stocks," said Mr Hayes.

"We are very pleased to have worked in partnership with the Environment Agency and Wiltshire Council to improve this track and recognise the environmental benefits this project has had on the River Till," said Rod Crossly, Farm Manager at Berwick Down Ltd.