Appendix 2: Clean and plentiful water


i) The blocking of drainage ditches by grouse moor owners and managers is likely to be improving water quality by preventing the further release of sulphur, nitrate, ammonia and metals that had occurred due to the lowering of water tables associated with peat erosion or drainage19.

ii) Water from functioning peatlands is high quality because vegetation, especially mosses and lichens, captures and retains a range of atmospheric pollutants17. The ONS estimates the annual value of UK drinking water from peatlands at £888 million and the asset value at £18.366 billion in 201620. These ONS estimates are based on the costs relating to both water supply and water treatment.

iii) By dividing these figures by the area of peatland in the UK (estimated by ONS as 2,962,622 hectares) and then multiplying by the area of English peatlands under grouse moor management (282,000 hectares8), we estimate that the annual value of English GMM to drinking water provision is c.£84.5 million and asset value c.£1.75 billion.

iv) Vegetation cover represents a key control on storm runoff in peatland catchments21, and therefore the quantity and quality of the water downstream.


v) Degraded peatlands comprise areas of exposed bare peat, which can adversely affect the quality of drinking water through increases in dissolved organic carbon, which causes brown peaty water22, acidity and concentrations of suspended sediments or fine particulate organic matter and metals19.

vi) Concerns have been expressed that disease control on grouse moors (notably flubendazole in medicated grit) could impact on water quality. Review work in Scotland suggested that while the risk was low, concentrations may be underestimated where there is poor practice and that uncertainties required further investigation23.


vii) Restoring degraded peatland through re-vegetation and grip blocking may affect the regulation of water supply. Rewetting and saturation with water is likely to lead peatlands to produce ‘flashy’ run-off17 reduced water quality24 through increased over-land flow. See also Flood mitigation (Appendix 4 - Reducing risk of harm from environmental hazards).

viii) The IUCN25 has noted that further research is required on the impact of climate change on water quality. However an increase in ‘intense’ rainfall events26 and changes in snow-lie are likely to influence water quality17 (notably particulate carbon losses via runoff) while drought and rewetting sequences increasing Dissolved Organic Carbon (DOC) losses27. Rainfall is likely to be more important than temperature in shaping long-term changes in runoff28.

ix) Peatland instability due to climatic and land management changes raises the risk of release of some heavy metals and Persistent Organic Compounds into river systems17 thereby affecting water quality.

x) Vegetative change in peatlands may occur due to climate change, land management and nitrogen deposition29and this can affect DOC losses30.


xi) The impacts that controlled burning (and interactions with drainage and grazing) may have on water quality are still not well understood.  Study results differ depending on timescale since burning event and spatial scale. Commonly cited studies of burning and water colour have highly divergent views31-33.