Peatlands above Loch Katrine restored in bid to protect water supply for millions

Scottish Water has completed the second phase of a major peatland project surrounding the loch in the Trossachs region, restoring a further 94 hectares of degraded areas.

The project is part of a decade-long effort to protect drinking water supplies for more than a million people in and around Glasgow.

The work, carried out by engineering contractor George Leslie, forms part of a wider environmental strategy that aims to restore up to 400 hectares of peatland across the Loch Katrine catchment over the next ten years.

While peatlands are often discussed in the language of climate targets and carbon storage, Scottish Water said the project is also rooted in making sure Glasgow’s water is clean.

Healthy peat acts like a vast natural sponge, holding water in the landscape and filtering organic material before it reaches reservoirs and rivers. But the company said drainage and degradation over the years have left many upland peat bogs damaged, allowing large quantities of dissolved organic matter to wash into watercourses during periods of heavy rain.

By blocking artificial drainage ditches and reshaping exposed peat formations known as peat hags, engineers said they are attempting to restore the land’s natural water retention capacity.

The result, they said, is less organic material entering Loch Katrine and a reduced burden on the treatment process required to turn the loch’s water into drinking water.

“Combined with the first phase of the project, which was carried out at the start of 2025, we have now restored over 200 hectares of peatland surrounding Loch Katrine,” said Michael Gilmour, Scottish Water’s project manager. “That’s an area equivalent to around 280 football pitches.”

Craig McDonald, site manager at George Leslie, said areas restored during the first phase last year were “recovering well”, helping reduce the flow of discoloured water into surrounding burns and streams.

“Increased amphibian activity within the dams created last year provides a strong indication that our efforts are bringing benefits not only to the biodiversity of Loch Katrine, but also increasing its capacity as a carbon store, reducing flood risks, and improving the water quality of the river and its tributaries,” he said.

The restoration forms part of a broader land management programme being developed by Scottish Water in partnership with Forestry and Land Scotland. Alongside peatland recovery, plans are under way to expand native woodland across the surrounding hills as part of the wider Great Trossachs Forest initiative.

Jared Stewart, who manages Scottish Water’s peatland restoration programme, said: “It is great to see the progress that is being made on delivering this important project which is a catchment level approach to protecting the source water quality at Loch Katrine for our customers, as well as improving the biodiversity of the area.”

The Loch Katrine scheme has received support through Peatland ACTION, the national programme funded by the Scottish Government to restore Scotland’s peatlands as part of its climate commitments.

Ministers have pledged £250 million towards restoring 250,000 hectares of peatland by 2030 — a recognition of the increasingly central role peat bogs are expected to play in flood prevention, biodiversity recovery and carbon reduction.

A third phase of restoration work at Loch Katrine is due to begin later this year.