Generally, galvanised steel and reinforced concrete have been used to construct fish passes, but the energy and carbon cost of using such materials is very high. So, as an alternative this entire pass was constructed of sustainably harvested Welsh Oak.
The bridge sill at Pont Wen has restricted fish passage since its emergency construction in 1993 when the bridge was lost due to floods. Fish have found it difficult to swim past the structure and access the prime spawning and nursery areas upstream.
As a result the 36 km of prime nursery stream may have been under utilised for the past fifteen years. Improvements in fish passage ensures full access to the upper reaches of the Bran and helps safeguard salmon, sea trout, brown trout, eels and important conservation species like sea lamprey populations of the river Tywi.
The fish pass was installed during August and September at a cost of £20,000.
The Environment Agency Wales has been forging strong links with Coed Cymru (Welsh Wood) that work to develop markets for sustainably produced wood products. This ensured that the Oak is sourced from sustainably managed woodland sites. These deciduous Welsh woods are helping to provide an alternative to the current softwood Forestry management that predominates in Wales.
The work has been carried out as part of the Welsh Assembly Government’s funded Sustainable Fisheries Programme. This aims to maximise the social and economic benefits of angling in Wales.
Dave Charlesworth, Sustainable Fisheries Officers said: 'This has been a great project to be involved in and hopefully the improved access for fish to the river Bran will help to bolster returning adult fish populations in the main river Tywi, a fishery of international renown and great importance to the local rural economy. Additionally, delivery of such construction projects with sustainable materials helps to drive down the carbon cost, a consideration that we all have to make in the current climate.'
Rick Longford, Economic Development Manager, Monmouth County Council added: ‘This is partly what we set up the Wentwood Timber Centre for. We want to provide bespoke solutions to support environmentally sensitive projects in a sustainable way. The centre is proud to be working with the Environment Agency in this way, along with partners Coed Cymru and SIREN, the conservation education charity. We are keen to develop further links and projects with the Agency over coming months, to aid the viability of the centre.’