Morton Quarry Weir, Scotland

Reconnecting habitats that have been separated by this barrier will help to restore natural ecosystem services.

Introduction

The Forth is an iconic landmark for Scotland, and 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 and a wide range of wildlife. Made up of 13 river catchments, including several coastal burns, the Forth catchment is a unique and special place.

From Dunbar and Fife Ness in the East to Balquhidder in the West, to Kinross in the North and the Pentland hills in the South, the Forth catchment is vast and includes all rivers which flow into the Firth of Forth and Forth Estuary.

This project will focus on a single site, Morton Quarry Weir, on the Linhouse Water. The best habitat and water quality tributary of the Almond catchment. The mainstem of the almond has historically been highly fragmented with many weirs and urban modifications. This fragmentation was heavily reduced by installing 6 fish passes (technical and rock ramp) via the partnership project RiverLife: Almond & Avon 2016-2021, and later and Nature Recovery Fund project for removing the upper Seafield weir in 2022.

The River Almond rises in Lanarkshire near Shotts and runs through West Lothian, draining into the Firth of Forth at Cramond. The name Almond is simply old Celtic for “river”.

At a glance

Project typeDam removal (demolition)
Project statusComplete
Removal dateSeptember 2023
CountryScotland
RiverLinhouse Water, Almond
Km to be opened5
Key habitatsBedrock and gravel rivers
Focal speciesbrown trout, sea trout, salmon, stoneloach
WebsiteForth Rivers Trust

Project context and opportunity

The Forth is a very industrial region, and therefore, there are a huge number of now redundant weirs in the catchment, which are a barrier to migratory fish, as well as having a detrimental impact on the genetic diversity of fish populations in the area. Reconnecting habitats where these barriers have separated will help to reduce these impacts and restore ecosystem services.

The Forth Catchment is heavily fragmented, with hundreds of obsolete industrial and infrastructure structures across the 13 river catchments and various coastal stream systems. These are being removed or eased at approximately one per year nationally. At this rate, the national program will take hundreds of years to achieve naturalised rivers that are passable to migratory fish for the Forth. These weirs are also deprioritised due to being of benefit to brown trout, smaller populations of migratory species, and/or non-salmonid species. This ORP-funded project provides an opportunity to show a different way to alleviate the impact of barriers on local river systems and to advocate for our rivers and their wildlife. This is also an opportunity for the FRT team to advance their skill set at weir removal and to up-skill newer team members, which will inevitably be taken forward to further projects that benefit our rivers.

The Almond barriers project that, as part of RiverLife program, ran from 2016 to 2021 has already opened up the Almond for fish passage, which means there is now a greater impetus to remove barriers on its tributaries. The Morton Quarry Weir sits on one of these tributaries, the Linhouse Water, a highly popular walking route whose removal will open up 5 km upstream to help mend the lateral connectivity of a river that is a significant local beauty spot.

Project aims

To achieve its objectives, this project aimed to connect significant habitat areas by targeting this obsolete and degraded weir, which was neglected and forgotten. Often lost in time and ownership, these types of weirs subsequently have become lost in the Scottish system for planning and river restoration at the national scale. These weirs will not be removed or adapted unless organisations such as the Forth Rivers Trust come forward and push for their removal.

The ecological outcomes of removing Morton Quarry Weir are that species of migratory and resident fish will benefit. This will be achieved by restoring ecosystem services and reconnecting habitats across the stretches of the river. This should ensure that the Almond is in a better condition for future years.

In terms of economic and social outcomes, there will be savings to local authority budgets in maintaining or mitigating the impact of the structures. There will be a sense of increased ownership of the rivers through community and stakeholder engagement in the weir removals and gaining knowledge from undertaking the works that will contribute to future projects and can be shared with other groups undertaking barrier removal projects in rivers.

The objectives for achieving the weir removal are:

Ecological outcomes:

  • species of migratory and resident fish benefit from the removal of the weir structure
  • ecosystem services are restored, ensuring that the river is in a better condition for future years
  • and habitat connectivity is restored in this stretch of river.

Economic and social outcomes:

  • Increased local knowledge of the river system via community engagement
  • Savings to the local authority budget in maintaining or mitigating the impact of the structure.
  • A communication plan shares the work and knowledge gained from undertaking the work.

Political outcomes:

  • Removal of the weir will allow FRT to continue to play its part, at a suitable scale, in the restoration of the post-industrial rivers of the Forth.
  • It will add value to the national river restoration plans for achieving good ecological status for all Scottish rivers.
  • It will add value to national spending and restoration plan, as removing smaller weirs increases the value and urgency of national past and future delivery of migratory fish easement works.

Project achievements

The Forth Rivers Trust successfully removed the historic Morton Quarry Weir, an obstacle dating back to the 1800s oil shale industry, situated in the steep Linhouse Water gorge, a tributary of the River Almond in West Lothian. Overcoming challenging terrain, the Forth Rivers Trust team dismantled the 2-meter-tall weir by hand, carefully exposing and redistributing natural cobblestones downstream to enhance the Linhouse Water’s aquatic habitat. Despite obstacles such as high river flows, the team’s dedication prevailed, resulting in the significant achievement of restoring the Linhouse Water to its natural state.

Partners

Forth Rivers Trust