Essex Estuaries Complex

The Essex Estuaries complex is a highly sedimented estuary complex in the southern North Sea, located on the East coast of England. It covers an area of approximately 282 km2. It is made up of four estuaries; the Blackwater, Colne, Crouch, and Roach, as well as open stretches of coast along the Dengie Peninsular.  The main habitats are large areas of salt marsh and extensive intertidal mud and sand flats. European oysters and seagrass exist in patches in the estuaries.

The catchment of the estuary complex is predominantly arable agriculture, with centres of habitation in Chelmsford, Colchester, and smaller towns. The majority of the extra-urban catchment is agricultural land (Grade 2 & 3) on permeable deep loam soils, over London Clay, and some chalk in the upper reaches. Annual mean precipitation in the catchment is one of the lowest in the UK. Societal uses around the estuary include a rich social history of aquaculture (oysters), inshore fishing (commercial and recreational), water sports, sailing, and recreational and tourist industry use.  There is a 40-year history of restoration programmes for salt marsh, native oysters, and seagrass (N. noltii), and future challenges are sea level rise and coastal flooding, water quality, and human population growth.


Habitats Types in Essex Estuaries Complex




Salt Marsh


Sublittoral Mixed Sediments


  • Whole of estuary complex is bounded by sea defences, many constructed in 1953 and at end of built life span. 
  • UK Shoreline Management Plans (SMP) for area identify multiple areas for potential re-alignement in periods 2025-50, and 2050-2100.
  • MP currently being refreshed, and new sea level rise predication need to be included. 
  • Conservation (& restoration) of species and habitats in times of rapid changes and increasing human pressures (e.g., climate change

Main objectives

  1. 1
    Connecting the river with the land
  2. 2
    Climate pressures, water and population growth
  3. 3
    Restore landscapes, seascapes and ecosystems services
  4. 4
    Blue Economy and a “just” transition for communities

Key Opportunities

  • Excellent chrono-sequence of salt marsh restoration sites.
  • Good data provision, UoE and national
  • Other U.K. national programmes in B.C.Est
  • Engaged Blackwater Partnership group
  • Engaged local authorities and regional statutory authorities (e.g. Essex County Council, Environment Agency, Natural England)

Current and future restoration actions

Contact Person

Main contact
Graham Underwood