OLD HALL POINT
The saltmarsh and recharge around the point will help protect the ancient grazing marsh of Old Hall Marshes National Nature Reserve, most of which lies below sea level. The reserve is part of the SSSI and SPA/Ramsar site.
Inside the sea wall there are 287ha of unimproved grassland – representing the largest extent of this habitat remaining in Essex – 20ha of continuous reed bed, and 70ha of improved grassland, which can hold up to half of the Blackwater Estuary’s internationally important wintering population of dark-bellied brent geese. The grassland and ditch network support nationally important plants and invertebrates.
In the 109 years from 1888 to 1997, the saltmarsh at Old Hall Point reduced by 22.7%, exposing 2.6 ha of mudflat, and representing an annual average rate of loss of 241m. On the unprotected south shore, 1.61 ha of the marsh experienced losses at an average rate of 147m2 per year. A further 0.672 ha have been eroded up to the present day, with an annual rate of loss of width of between half and 1 metre.
Wave action, tidal currents and longshore drift has moved the recharge placed at the Point in 1998. The recharge has now formed a wide crest with a shallow seaward slope indicating a good dynamic equilibrium with the hydrodynamic forces acting upon it. Sands and gravels deposited at the southern point (North Channel foreshore) have mostly remained at the placement location, with limited movement shoreward and north-eastwards. Saltmarsh coverage due to rollover here is 425m2.
Internally, the saltmarsh is described as stable with no erosion or accretion recorded between 2000 and 2008. This situation appears to have remained unchanged in 2014 with a short, tight sward of saltmarsh grass, sea lavender, sea purslane covering much of the area.
The yellow area on the picture shows the proposed recharged site.