A Site of Special Scientific Interest (SSSI) just south of Bishop's Stortford, noted for its botanical diversity.
Thorley Wash was designated as a Site of Special Scientific Interest (SSSI) in 1986 for its botanical interest associated with tall wash grassland habitat. Wildflowers present include ragged robin, marsh marigold, fen bedstraw and meadowsweet. There are also records for early and southern marsh orchids.
The wet habitats are good for a diverse range of wildlife including dragonflies, damselflies, birds and bats. Areas of long vegetation provide shelter for small mammals and reptiles.
Hertfordshire Wildlife Trust
Floodplain grazing marsh and rush pasture
Desmoulin’s whorl snail, early marsh orchid and water rail