Filtering Functions

The quality of a peatland's filtering function primarily depends on high water levels. Therefore, the median annual water levels (water heights) are the basis for the assessment of the filtering status as a service. The water heights are determined from soil and vegetation parameters:
→  Core Parameter Water Level

Subsequently, their potential to discharge matter is assessed and examined in groundwater and surface water by querying and assessing possible discharge paths.

Median Annual Water Level as Indicator for the Filtering Status Discharge Paths

Water Height


Rating Scale

Discharge into groundwater

Discharge into surface waters
5+ Substance Sink from Peat Formation Good None None

5+/4+ and 4+

Substance budget in balance or minor substance source Medium Discharge paths available, if a peatland is within the catchment funnel of the drinking water's well gallery Discharge paths available, if intact sinks or pipelines converge with waterways and drain towards them, or there's a direct association with a lake, pond, stream or river
≤ 3+ moderate to strong substance source Poor

Peat soils, which show peat formation, are matter sinks and are assessed as „good“. Significant about them is their long-term capacity to store nitrogen, phosphorous as well as carbon. The assessment grade „medium“ refers to sites which status can neither be clearly identified as sink or source. For peatland soils which are the more thoroughly drained (assessment grade „poor“), potential discharge paths are examined, and mapped according to their threat to groundwater and/or surface water.

Decision Support Tool