Human Environment


The Severn Estuary has long been a focus of human activity. People have lived and worked around the Estuary for millennia. It provides attractive settlement prospects, including resources (food, water, raw materials) as well as significant opportunities for trade and leisure. The Estuary is home to a relatively large human population of approximately 1 million people1.

Within the Severn Estuary region there are significant conurbations with populations in excess of 100,000 people, including those around Cardiff, Newport and Bristol. There are also many other smaller towns and rural settlements on the extensive coastal plains around the Estuary (Fig. 1).

Local Authority Areas

Bristol and Cardiff have the highest total populations within the area, with 428,234 and 346,090 people, respectively3. There is a slightly greater total female than male population in all Severn Estuary local authority districts (Fig. 2).

Population has increased in almost all Local Authorities around the Severn Estuary over the last decade, with the exception of West Somerset where the population has decreased by approximately 1% since the 2001 census (Fig. 2). The Forest of Dean has experienced only a small increase while most other locations have grown by approximately 6-8%. The cities of Cardiff, Bristol and Gloucester have experienced the greatest increase (Fig. 2).

Population Density

Population density in local authority districts varies considerably.  The highest values are found in Bristol (average: 39.1 permanent inhabitants per hectare), Gloucester (average: 30 permanent inhabitants per hectare) and Cardiff (average: 24.7 permanent inhabitants per hectare).  These areas correspond with the major cities of the estuary. In contrast, Somerset has the lowest population density with an average of 0.5 permanent inhabitants per hectare (Fig. 3).

The Aging Population

Life expectancy is continuing to rise throughout the UK due to an increasing life expectancy for both men and women.  Older citizens are therefore forming a larger proportion of the population over time.
In the Severn Estuary, the highest percentage of citizens over 60 reside in the Forest of Dean, Monmouthshire, Sedgemoor, North Somerset and West Somerset. On the other end of the scale, Bristol and Cardiff have the lowest percentage of citizens over 60 (fig. 4) and have also witnessed a slight decrease in these citizens between 2001 and 2011.  This trend is thought to reflect the migration of retired persons out of the cities and the influx of students4.


  1. Joint Nature Conservation Committee (JNCC) 1993-01. An Inventory of UK Estuaries: South-West Britain v.2
  2. Environment Agency. 2013. Severn River Basin District: Challenges and choices.
  3. Neighbourhood Statistics, 2011. Office of National Statistics, Crown Copyright
  4. The Cardiff Economy and Labour Market Report, July-December 2010. Cardiff Research Centre. The County Council of the City and County of Cardiff. Accessed December 2013
  5. 2011 Census First Release, July 2012. Office of National Statistics, Crown Copyright
Last Updated Autumn 2014

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