Groundwater Dependent Terrestrial Ecosystems (GWDTE)
Groundwater Dependent Terrestrial Ecosystems (GWDTE) are wetlands such as springs, flushes and fens which are fed by groundwater rather than rainfall or surface runoff. They are particularly sensitive to hydrological and ecological changes caused by development. Foundations, borrow pits and linear infrastructure such as roads, tracks and trenches can disrupt groundwater flow and impact upon these sensitive habitats.
The Scottish Environment Protection Agency (SEPA) and the Environment Agency (EA) have a responsibility to protect GWDTE and regulate development which may have a negative impact on GWDTE. In Scotland, the Water Environment (Controlled Activities) (Scotland) Regulations 2011 (CAR Regulations) provide the regulatory framework.
To assess the potential risks to GWDTE, SEPA/EA require a vegetation survey to be provided identifying wetland habitats present both within and outwith the development site boundary. This survey should include a buffer of 100m radius of all excavations less than 1m in depth and within 250m of all excavations deeper than 1m. Wetland habitats are assessed on whether they are likely to be moderately or highly groundwater dependent or whether they receive water from other sources (rain or surface water runoff).