New Restoration Projects Planned

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Thanks to funding from the Scottish Government's Nature Restoration Fund managed by NatureScot, GFT has been working over the past year to design four exciting new restoration sites across the South West of Scotland.

The designed works will comprise a range of river restoration techniques, from the creation of wetlands, meandering of river channels and instream habitat improvements.  GFT carries out lots of tree planting each year, but these additional types of habitat restoration work play an equally crucial role in improving river habitats for native fish populations and wider biodiversity.

Restoring old meanders to rivers creates longer channels, and subsequently more fish habitat.  As the instream habitat is also more diverse than that of a straightened river channel, the habitat is also of a higher quality.  At the same time, creating riparian wetlands provides diverse habitats for invertebrates, an important food source for birds, fish and much of the food web.

These forms of habitat restoration also greatly improve the river’s resilience to climate change.  Instream habitat improvements such as the pinning of large wood into the channel creates scour, forming deeper pools, and places for fish to take refuge during floods and droughts.  Likewise, wetlands can store large volumes of water which slowly percolate back into the channel and mitigating against droughts.

Each of the project sites combine a range of different restoration techniques, having been deemed as those most appropriate and effective for each site. These designs were put together thanks to the work of CBEC Ecoengineering, who specialise in river restoration and with whom GFT worked through the duration of this project. The sites include:

Site A: Water of Luce

At this site, GFT is working to re-naturalise an 800m section of the river.  Back in the 1800s, a channel was cut through the valley side, through which the Main Water of Luce was diverted.  The valley side through which it was cut is a raised peatland and as a result, a significant amount of peat erosion has occurred since the flow diversion and reducing water quality.  The new channel was also entirely straight, lacking in instream habitat and approximately 400m shorter.

The river still flows through this route, however satellite imagery and hydrological modelling show that the former meandering channel still exists beneath the surface of the now dry valley bottom.

With the help of CBEC Ecoengineering, we have designed works to block the channel diversion through the peatland, and restore flows to the channel proper.  This will restore as much as 400m of additional river habitat, of which will be significantly greater quality.  Atlantic salmon spawn in this area, and will benefit from the improved water quality and increase in spawning and juvenile habitat.

Projects such as these required a range of surveys and hydrological modelling to ensure that there are no adverse and unintended consequences of carrying out the restoration work, for example by increasing the chances of flooding downstream.

Site B: Tarf Water 

Similar to the Water of Luce site, but at some time in the mid 1900s, a burn in the River Bladnoch catchment was diverted by a much shorter route to a new confluence with the Tarf Water.  This diversion led to the drying out of 800m of the burn, whilst the 200m ditch that replaced it provided little to no river habitats.

As this was done more recently than the diversion at the Luce site (above), the original route of the burn still shows on the OS map. This project explored the viability of restoring flows to the former channel, and the logistics of doing so.

Salmon populations are showing gradual recovery from acidification in this area of the catchment, and this work would provide important spawning and juvenile habitat to fast-track this recovery.

Site C: Shirmers Burn

Restoration of rivers does not always require engineering work or machinery.  Low-cost and low-tech techniques also play an important role in restoring river habitats.

At this site, a tributary of the Water of Ken, we explored ways of improving hydrological function to the watercourse, allowing it to more readily access its floodplain.  Work of this kind can greatly enhance the biodiversity of floodplain habitats, whilst also restoring more natural flow regimes where water can be stored and slowly make its way back into the channel.

Low-tech interventions such as fixing large wood structures into the channel can help to diversify instream habitats, whilst also deflecting flows out onto floodplains - where this is desired – when located appropriately.

GFT commonly carries out work of this kind, for which there can be opportunities for volunteers to get involved.  Do get in touch if you might be interested.

Site D: Crosslaw Burn

This burn in Moffat flows into the Annan Water, which shortly downstream meets with the Moffat and Evan Waters to form the River Annan.

Once an area of diverse wetland habitats on the floodplain of the Annan Water, this site has been historically drained. Now on the site of the new Moffat Distillery, the landowners wanted to explore how they could provide more for nature, and how the section of the Crosslaw Burn that flows across it could be enhanced.

Working with CBEC Ecoengineering, and with help and input from the local guys at Restoring Annans Water, GFT has designed a restoration plan for the site.

This work would create new areas of wetland, through which a meandering burn flows, providing diverse freshwater habitats and retaining far more water than it did before, mitigating against the impacts of climate change.

Being so close to Moffat, and all the associated development and infrastructure, this site required extensive hydraulic modelling, carried out by cbec eco-engineering, to ensure the enhanced water retention on the site does not have impacts on those up or downstream.

Further Information

• Annan FIRNS Project