The Monmouth New Hydro Scheme, which incorporates the Osbaston fish pass, is a hydroelectric scheme in Osbaston, near

Monmouth Monmouth ( or ; ) is a market town and community (Wales), community in Monmouthshire, Wales, situated on where the River Monnow joins the River Wye, from the Wales–England border. The population in the 2011 census was 10,508, rising from 8 ...

, in South-East Wales.

Description

The scheme produces 670,000 kW hours of electricity per year, which is enough to power 152 homes. It also provides heat for the landowner, Ronald Kear's, home. The scheme is built around two

screw turbine file:Archimedes-screw one-screw-threads with-ball 3D-view animated smal back.gif, Reverse action of the Archimedean screw, the principle of the screw turbine gaining energy from water flowing down through the screw file:Helical screw single double ...

s. These

Archimedes' screw The Archimedes' screw, also known as the Archimedean screw, hydrodynamic screw, water screw or Egyptian screw, is one of the earliest documented hydraulic machines. It was so-named after the Greek mathematician Archimedes who first described it ...

s are operating in reverse, with water flowing down, to power generators. An earlier hydroelectric power station had been on the site from 1896 until 1953, which itself was built on the foundations of an even older forge. Alongside the scheme is the Osbaston fish pass, built by the

Environment Agency Wales Environment Agency Wales () was a Welsh Government sponsored body that was part of the Environment Agency of England and Wales from 1996 to 2013. Its principal aims were to protect and improve the environment in Wales and to promote sustainabl ...

at a cost of £600,000. The fish pass allows river-spawning fish, such as salmon, to access an extra 125 miles of river - something which they had not been able to do since Osbaston Weir was put in place in the 18th century. New fish pass at Osbaston Weir - geograph

New fish pass at Osbaston Weir - geograph

The power station was officially opened on 23 September 2009 by the

Earl of Wessex Earl of Wessex is a title that has been created twice in British history – once in the pre-Norman Conquest, Conquest Anglo-Saxon nobility of England, and once in the Peerage of the United Kingdom. In the 6th century AD the region of Wessex ( ...

. Several months later, in June 2010, local schoolchildren released salmon into the

River Monnow The River Monnow () marks the England–Wales border for much of its length. After flowing through southwest Herefordshire, England, and eastern Monmouthshire, Wales, its confluence with the River Wye is approximately south of Monmouth. The ...

at the site of the power station - the salmon were initially reared at their school, Osbaston Primary School, as part of a class project. Once the salmon became fry, they were taken to Cynrig Hatchery, in

Brecon Brecon (; ; ), archaically known as Brecknock, is a market town in Powys, mid Wales. In 1841, it had a population of 5,701. The population in 2001 was 7,901, increasing to 8,250 at the 2011 census. Historically it was the county town of Breck ...

. The fish pass is not only used by salmon, but also larger creatures - in June 2010, a camera set up at the site of the fish trap caught footage of an

otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine. Lutrinae is a branch of the Mustelidae family, which includes weasels, badgers, mink, and wolverines, among ...

swimming through the trap.

References

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