Improving and protecting drinking water quality at Sandy Loch, Shetland

Peatland ACTION Project Officer Lauren Dixon explains the link between healthy peatlands and drinking water by telling us about the restoration work at Sandy Loch, Shetland.

Large bare peat surface contributing to high organic load and colour at the water treatment works (WTW). ©Scottish Water, Sustainable Land Management Team
Large bare peat surface contributing to high organic load and colour at the water treatment works (WTW). ©Scottish Water, Sustainable Land Management Team

Sandy Loch

The restoration site is situated within the Sandy Loch drinking water catchment on Shetland.

Sandy Loch is a 440 hectare catchment, that Scottish Water use to provide around 12,000 customers with drinking water. More than 20% of Scotland is covered by peat; however peatlands make up approximately 70% of Scottish Water’s drinking water catchments.

Land within this catchment is typical rough grazing which has been modified over decades, possibly centuries, from peat cutting for domestic fuel and pasture improvement for livestock.

Large areas of bare unvegetated peat within the Sandy Loch drinking water catchment were contributing to the high organic loading and brown water entering the loch, and ultimately the water treatment works. The peat was likely eroded as a result of a change in land management practices, and made worse by rain and wind erosion which washes the peaty soils into the loch. Although this water is perfectly safe to drink, it can require a lot of treatment before it reaches the quality that customers expect.

Peat Pan Stabilisation

Following consultation and advice from Peatland ACTION, restoration phase 1 took place in March 2017 and involved creating bog-pools over the area of exposed peat right next to the loch. The aim was to slow the flow of water, trap and reduce the loss of peaty sediments into Sandy Loch. This also provides conditions to allow for the re-colonisation of bog plants, particularly sphagnum, a key ingredient in maintaining a healthy peatland habitat. To further encourage the re-colonisation process, sphagnum moss ‘plugs’ were added directly to the areas of bare peat.

Initial results of phase 1 indicated that these techniques worked well and further stabilisation was completed on a larger scale during phase 2 of the project this summer. 27 hectares have seen restoration activates during phase 1 and 2, with a further 20 hectares planned to complete the project.

Reprofiling

Restoration activities also included reprofiling peat hags (overhang of bare peat). If these are left exposed to the elements (wind, rain and frost), the overhang would eventually collapse and large chunks of peat would be washed away. To prevent this, steep hag edges were reprofiled to about a 30 degree angle and vegetation stretched over the reprofiled surface. The vegetation also protects the peat from erosion by acting as a barrier to water, frost and wind.

Peatland ACTION on the road to… improved water quality

The partnership working between Peatland ACTION and Scottish Water means restoration activities at Sandy Loch has improved and protected the drinking water catchment. It is also expected to reduce the requirement for energy and chemicals used to treat the water in the future. Additionally, the work here will contribute to an improved aesthetic environment for those who visit the area. It is also contributing to and maintaining Scotland’s natural carbon storage and resilience to climate change.

Glass filled with clean water, and sphagnum moss being squeezed in the background. ©Fiona Mann/SNH

Find out more in the following links:

If you would like to contribute to the on-going work of Peatland ACTION, we would like to hear from you. For further details please contact peatlandaction@snh.gov.uk

For information about Peatland ACTION including videos and leaflets visit the project webpage

Scottish Water’s Sustainable Land Management (SLM) team is working in collaboration with land owners and developers to protect drinking water sources throughout Scotland. For more information please visit www.scottishwater.co.uk/slm

Find out more about Lauren’s secondment from the Scottish Water SLM Team to nature.scot in her blog earlier this year.

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