Thorley Wash or Thorley Flood Pound is a 17.3-hectare biological Site of Special Scientific Interest in Thorley, south of Bishop's Stortford in Hertfordshire. It was formerly a flood pound for the

Stort Navigation The Stort Navigation is the canalised section of the River Stort running from the town of Bishop's Stortford, Hertfordshire, downstream to its confluence with the Lee Navigation at Feildes Weir near Rye House, Hoddesdon, Hertfordshire. H ...

, which was decommissioned in 2004 and converted to a more natural state. It was purchased by the

Herts and Middlesex Wildlife Trust Herts and Middlesex Wildlife Trust manages over 40 nature reserves covering nearly north of London, in Hertfordshire and the historic county of Middlesex, part of which is divided between the London boroughs of Barnet, Enfield, Harrow and Hill ...

from the Environment Agency in 2011. Habitats include tall wash grassland, which is now rare, marsh and waterlogged grassland. It has a wide variety of plant species, including

reed sweet-grass ''Glyceria maxima'' (syn. ''G. aquatica'' (L.) Wahlenb.; ''G. spectabilis'' Mert. & W.D.J. Koch; ''Molinia maxima'' Hartm.; ''Poa aquatica'' L.), commonly known as great manna grass, reed mannagrass, reed sweet-grass, and greater sweet-grass is a ...

and meadowsweet. There are flowers such as

fen bedstraw ''Galium uliginosum'' or fen bedstraw is a plant species of the genus ''Galium''. It is widespread across most of Europe as well as Morocco, Western Siberia, Turkey, Kazakhstan and Xinjiang. It is reportedly naturalized in New Zealand, Greenland ...

and early marsh orchid. Breeding birds include snipe and water rails. The site also has the endangered

Desmoulin's whorl snail Desmoulin's whorl snail (''Vertigo moulinsiana'') is a species of minute air-breathing land snail, a terrestrial pulmonate gastropod mollusc or micromollusc in the family Vertiginidae, the whorl snails. This species was named in honor of the ea ...

, which is in the Red Date Book, together with diverse dragonflies, damselflies, birds, bats, small mammals and reptiles. There are five wooden sculptures by Daniel Cordell, commissioned by the Wildlife Trust in 2012. The Stort Navigation forms the boundary between Hertfordshire and Essex, and the site is on the Hertfordshire bank, but access is by a bridge from the towpath on the eastern Essex side. Access is restricted to footpaths due to the dangerous deep silt on the site.

References

{{coord, 51.8434, 0.1615 , type:landmark_region:GB-BNE, display=title Sites of Special Scientific Interest in Hertfordshire Herts and Middlesex Wildlife Trust reserves East Hertfordshire District