22 Mar 2025
In honour of World Water Day 2025 (Saturday, 22nd March), we have highlighted some of the key roles peatlands play in maintaining water quality.
Peatlands store a large proportion of global freshwater resources and thus play an important role in maintaining water quality. The waterlogged conditions in peatlands prevent plant material from fully decomposing and allow the forming of peat soil by the partially decomposed material. This enables the storage of large amounts of carbon adsorbed by the plants from the atmosphere within peat soils, providing a net-cooling effect. The waterlogged peatlands also provide a natural buffer against acidification and eutrophication as they lock up nutrients such as sulphur and nitrogen. As a result, water sourced from healthy peatlands is naturally of high quality with few pollutants and low nutrient levels.
In Ireland and the UK alone, around 85% of our drinking water is sourced directly from peatlands. In particular, Ireland’s midlands are facing a significant and widespread reduction in water quality due to peatland degradation, with high fluvial nitrogen and carbon concentrations present in streams. At a global scale, research shows that only around 28% of water-supplying peatlands remain pristine or protected. This highlights the urgency for peatland restoration and responsible stewardship.
Impact of peatland drainage
Draining peatlands lowers the water table and leads to the decomposition of plant material, soil shrinkage and the release of CO2 emissions into the atmosphere. It also affects the water quality within the bog itself and downstream water bodies through the release of pollutants such as ammonium which is toxic to fish. This leads to challenges to aquatic life, including increased mortality, reduced species richness, habitat alterations and changes in community structure.
Rewetting peatlands can often offer a more affordable and sustainable way to improve water quality, avoiding expensive treatments or the use of chemicals. Find out more about how the Peatlands and People project is helping to restore peatlands and improve water quality in the Midlands here.
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