It looks like a natural rock fall in the river, but is actually a sophisticated piece of engineering work.
In the River Almond at Howden Bridge, Livingston, the historic Howden Weir has been sensitively transformed into an 85 metre long rock ramp - the largest in the UK. A rock ramp is a series of pools and riffles created by strategically arranging rocks in the weir to allow fish to pass over and migrate upstream.
With the cooperation of several organisations - including a local family of otters who have a vested interest in the return of the fish and a healthy river - the work was completed over summer 2019. It will allow the iconic Atlantic salmon and sea trout from the North Sea to migrate up the Almond to spawn after their sojourn in the ocean. Along with other species they will re-colonise and rejuvenate the river eco-system, bringing other wildlife such as invertebrates, otters and kingfishers.
With the cooperation of several organisations - including a local family of otters who have a vested interest in the return of the fish and a healthy river - the work was completed over summer 2019.
Howden Weir was originally built to power a water wheel for a grain mill, and then later the New Calder Paper Mill which produced brown wrapping paper here from the 1800s. But for the past 200 years it has been a barrier to fish attempting to migrate.
The new rock ramp was built between existing islands across the face of the weir to form a waterfall-like structure made up of pools, runs and easy leaps. Over 9000 tonnes of rock was used, much of it recycled from other developments in West Lothian. The rocks are embedded in concrete to stop them being swept away in bad weather when the river’s flow is rough, and two passages have been designed so that there is always water in them, even during times of low rainfall. One of the passages has a faster flow than the other, so different fish species can choose whether they like the fast or the slower flow to climb the ramp. Pools at intervals provide a space for fish to rest and hide under the rocks from predators. A huge amount of work went into preserving the existing islands with the trees and shrubs established on them, as well as keeping track of the wildlife on the banks of the river during the construction work; one family of otters in particular remained totally involved on site, playing in the rocks each evening after the workers finished.
The River Almond used to have the dubious distinction of being the most polluted river in Scotland, thanks to the industrial past of the area through which it flows. A lot of cleaning up has been done over the years and wildlife is gradually returning. In migration season (May to October) you can observe fish jumping weirs but their success rate isn’t as high as it should be - they’ve been filmed at Mid Calder Weir continually hitting the rocks and getting exhausted. The cumulative impact of all the weirs on the River Almond means that very few fish are making it to the upstream sections and tributaries. Fish passes were constructed on some of the weirs a long time ago but are not working well. So the Howden Weir Rock Ramp is just one of a series of projects being undertaken by RiverLife: Almond & Avon, to continue to improve the health of the rivers.
One of the passages has a faster flow than the other, so different fish species can choose whether they like the fast or the slower flow to climb the ramp. Pools at intervals provide a space for fish to rest and hide under the rocks from predators.
The first barrier fish encounter is the Fair-a-Far Weir at Cramond, where the Almond flows into the Forth. Work is also planned for the weirs at Mid Calder; Kirkton Weir at Almond Valley Heritage Centre, the Rugby Club Weir in Livingston; and Dowies Weir. For each of the different sites the best option for easing fish passage has been identified.
The projects not only benefit wildlife but also the communities connected to them. A large part of RiverLife’s remit is community engagement. Tree planting, river bank restoration and riverside furniture repair work has been delivered, as well as activities such as guided walks, invasive species identification and documentation, and the popular primary school education programme Fish in the Classroom.
The River Almond used to have the dubious distinction of being the most polluted river in Scotland
If you would like to get involved in river conservation and restoration, there is always something going on for volunteers and RiverLife would be delighted to hear from you. Please visit RiverLife:Almond & Avon at www.river-life.org.uk, follow on twitter at @myRiverLife and on facebook through the Forth Rivers Trust page.
About Forth Rivers Trust and RiverLife: Almond & Avon
The Forth is an iconic landmark for Scotland; the Estuary and Firth, along with its tributaries, have driven industry over the centuries. The Forth catchment spans a vast area covering over 3000km² and is home to roughly 25% of Scotland’s population together with a wide range of wildlife. From Dunbar and Fife Ness in the East to Balquhidder in the West, to Kinross in the North and the Pentlands in the South, the Forth catchment is vast and includes all rivers which flow into the Firth of Forth and Forth Estuary.
The Forth Rivers Trust aims to engage people with rivers and wildlife whilst conserving rivers and their important species for future generations. Projects range from full scale restoration of rivers to engaging communities through organised events.
RiverLife: Almond & Avon Project is an ambitious programme of works. It is a partnership project between the Forth Rivers Trust, West Lothian Council & City of Edinburgh Council, funded by the Heritage Lottery Fund, SEPA Water Environment Fund, The Scottish Government, West Lothian & City of Edinburgh Councils.
Article published in Konect December 2019
Author: Helen-Jane Shearer