Flap Valves - The Essex Way Traditional Cache

Grazing marshes were created from Medieval times by building sea walls across tidal mudflats and salt marsh. It is relatively flat, low lying, periodically flooded grassland, pasture or meadow drained by a network of ditches.

The ditches and flap valves in the sea walls let water drain out at low tide and prevent the sea or tidal river from entering at high tide.

The cache is down the steps in a corner under ground cover.

The grazing marshes’ drainage ditches often receive saltwater from seepage through sea walls and embankments, or over topping during high spring tides. The ditches are especially rich in plants and invertebrates. These habitats are particularly important for wading birds.

There are an estimated 6500ha of coastal and floodplain grazing marsh in Essex – and targets have been set to maintain 6175ha restore 325ha and create 250ha.

Areas of species rich coastal grazing marsh are designated as Sites of Special Scientific Interest (SSSI). Additionally, those of importance for their migratory bird populations are designated as Special Protection Areas (SPA) and Ramsar sites.