Fish on the River Aln to be given a helping hand

Fish returning to their spawning grounds on the River Aln are to be given a helping hand.

By The Newsroom
Monday, 15 July, 2019, 16:45
One of the weirs on the River Aln, viewed towards Alnwick Castle from Denwick Bridge. This picture was taken by Gazette reader George Taylor.

Plans have been submitted by Northumberland Rivers Trust to build five new fish and eel passes at weirs in the Alnwick area.

The Trust has secured a grant from the Environment Agency and support from Northumberland Estates for the works, scheduled to take place over the next two years.

A sea trout at Oliver's Mill. Picture by Vince Audsley.

Peter Kerr, Trust director, in the planning application, states: ‘These are essential to allow salmon, sea trout, brown trout, eels and lamprey get upstream to spawn, (and also help with downstream migration).

‘The existing fish passes at the sites are outdated, only work for certain species in certain flow conditions and their timber construction is deteriorating.

‘The weirs are all important historical structures (designed by Capability Brown) and so great care will be taken to not damage them or affect their appearance.

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‘The works will use the same footprint as the existing passes where possible, although we will extend these at some sites to create resting pools. We will use stone facing to the structures at all visible sides to ensure that the new passes fit into their local environments.’

Initial designs have already been agreed by the Environment Agency and the Trust has applied for a Flood Risk Environmental Permit.

It is intended to build the passes at Denwick Upper and Castle Weir between December 2019 and March 2020, the passes at Denwick Lower and Filberthaugh between July and September 2020 and to complete the works at Canongate Weir between January and March 2021.

Peter added: ‘The new larinier and Alaskan A fish passes are formed from chutes with steel baffles to slow up the flow rather than the series of low weirs and pools of the existing fish passes.

‘We therefore need to lower the bases of the existing passes to get down to the correct levels for the new passes and remove the cross weirs in the existing passes.

‘The main weirs will be unaffected by the works other than the cutting of a small notch at the eel passes to ensure that they attract flow in all conditions.’