Peat extraction for commercial or domestic purposes, and modification or drainage of peatlands for other uses such as forestry or agriculture, has been identified as a significant pressure. The extractive industry has been identified as a significant pressure on about 5% of high status objective water bodies which are at risk of not meeting their water quality objectives. This is the fifth most prevalent significant pressure type in high status waterbodies.
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:
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 catchments.ie