Area and population density

Created 2 years ago, updated 16 days ago

National Statistics has identified a need for a consistent approach to the production of definitive surface area measurements for use in UK statistical outputs and to meet the European Commission’s requirements for standardised area measurements (SAM) from member states.

Area to mean high water

This is the total area of an area and includes all tracts of inland water. For all inland (i.e. non-coastal) areas, the measurements respect the statutory boundaries and so the area measurements are the same as those available for the ‘Total extent’.

Inland water

Inland water measurements have been calculated using a frozen 2002 extract of the Ordnance Survey MasterMap® topographic layer’s hydrology theme. In producing SAM figures, inland water is constrained to ‘bounded’ areas of water such as lakes, lochs, reservoirs etc and does not include ‘open tracts’ of water such as rivers, canals, streams etc. Only those tracts of inland water with a surface area measurement of 1km2 or more have been included; the 1km2 constraint refers to each single instance of inland water in total rather than to a part of an area of inland water that falls in any given area.

Area to mean high water excluding inland water (land area)

This area measurement is the difference between the ‘Area to Mean High Water’ and ‘Area of inland water’ where such a measurement is available. This area may be loosely defined as the ‘Land area’.

These are all ‘flat’ measurements as represented on a map; they do not take into account variations in relief e.g. mountains and valleys. Measurements are given in hectares (10,000 square metres).

Population density

Following the recommended approach preferred by Eurostat, the ‘land area’ measurement (area to mean high water excluding area of inland water) has been used to compile population density figures.

Tracts of inland water in Surrey taken into account in producing measurements


Walton North ward - Queen Elizabeth II Storage Reservoir (1.28 sq km)


Laleham and Shepperton Green ward - Queen Mary Reservoir (2.86 sq km)

Staines ward - Wraysbury Reservoir (1.99 sq km)

Stanwell North ward - Staines Reservoir (1.42 sq km)

(1 sq km = 100 Hectares)


Includes County, Local Authorities, Wards (2016 boundaries), LSOAs.