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Peat extraction pressures

The main impacts on water quality and river habitat arising from peat extraction and drainage include the release of ammonium and fine-grained suspended sediments, and physical alteration of aquatic habitats.  The most likely situations for generation of suspended sediment from peat are:

  • Mechanised peat extraction where milling, drying and harrowing, and peat harvesting creates loose peat particles which can be washed and blown into streams;
  • Installation of drainage channels in peat which results in flow pathways for sediment reaching water bodies and;
  • Erosion following heavy rainfall.

The ammonium arises from lowering the water table in the peat when it is drained, which breaks down the peat and releases ammonium. Further research is required to precisely understand this process, and the combined impacts of ammonium, pH and dissolved organic carbon on the aquatic environment.

Drainage of peatlands also results in changes to the hydromorphological condition of rivers, for example, modification of the channel bed and riparian area, river channel diversions altering the river network, increasing the connectivity of land drains to the river network, and altering the flow and sediment regime.  For more information on the effects of agriculture on water quality, please go to