"A Clear Future for our River"

Monthly Archives: December 2012

Flow Deflectors Project

river deflectorsMuch of the Bristol Avon has many weirs with a short stretch of oxygenated water below them followed by the river quickly losing its energy.  This project was designed to concentrate the little flow there was to scour the centre of the river. This was achieved by building natural flow deflectors, in this case willows, which were collapsed into the river and pinned. They have become natural barriers to the flow sufficient to scour the centre of the river in normal conditions, but have withstood all major flooding as the extra water flows through and over them.

Sediment is deposited behind the deflectors and over time has encouraged plant growth and a shallow area which warms quickly in the Spring and Summer. They are excellent areas for fry to develop out of the flow and where they can seek some shelter from predators. In higher water the slack areas created shelter many species of fish.

Within days of these being created the deflectors were being used by duck, kingfishers and wrens and in the first winter provided a great foraging area for long tailed tits.

Bankside “buffer zone” Project

A Cattle Poached Bank

A Cattle Poached Bank

Buffer Zone Recovery

Buffer Zone Recovery

The two views in these photos show a stretch of river which had been badly poached by cattle leading to the banks being denuded of all vegetation. The result is not just offensive to the eye but has also reduced insect life to the detriment of birds and fish populations.

The second photograph shows the same view after the fencing had been erected for only a short period, just a few months.  The area protected by the fencing has regrown with a variety of plants providing seed for visiting birds (charms of goldfinches visit regularly) and has begun to provide bankside cover for fish. It is now several years since this work was completed and the effects are even more pronounced. The stretch has now become much more useful to the local angling club who stock trout into it. The stretch also produces grayling, dace and roach.

This project was completed following advice by Dr Mark Everard and was managed by Dr Sid Jevons on behalf of their local angling club. Funding was kindly provided by the environment agency.