Abingdon Reservoir

The Abingdon Reservoir (also known as the South East Strategic Reservoir Option, or SESRO) is a long-term proposal for fresh water storage for the Home Counties. Located south west of Abingdon, Oxfordshire in the mid-west of the Thames Basin, it is intended to help support water supply provision in the south-east of England. The proposals have been developed with Southern Water and Affinity Water and is intended to serve all three company’s customers.

Proposals
The proposal arose in 2006 by Thames Water. In 2007 the Environment Agency opined that need for this was not proven. Further arguments were put but the near-term-demand case was rejected in 2011. In 2023, following a period of consultation, a revised version increased the proposal to 150 e9l.

This would make Abingdon the second-largest reservoir in England by capacity, exceeded only by Kielder Water at 200 e9l, pushing Rutland Water into third place at 124 e9l. Across the whole of the UK, only seven Scottish lochs have greater freshwater storage by volume.

Since 2018, a longer-term proposal stands, for its building, by 2043 to cater to projected population growth in the Thames Basin.

Reasons for the construction
The main reason to build is that the South-East is facing significant seasonal water stress. Factors are the rain shadow behind the prevailing westerly winds and western hills. Eastern counties lack the rainfall of the west; their average annual rainfall being 500-750mm. The west receives around 1800-2800mm.

Average population density is higher in the eastern than western counties; London houses 13.5% of the UK's population. This is the greatest concentration of domestic water usage. Roughly 22% of water use is domestic; 75% is from all types of industry.

Counter-arguments
GARD or the 'Group Against Reservoir Development' have counter-arguments, local, national, and international comparators.
 * Thames Water have unambitious targets for leakages
 * The reservoir will be far from potent against long droughts
 * As there is enough water to supply London now there can be in future using other, sustainable methods.
 * Impacts on the ecosystem being transformed from supporting many endangered and protected land-based invertebrates, water voles, bats and hedgehogs to more water-based bird life.
 * Traffic congestion and construction pollution.
 * Local economic loss of many well-rooted businesses and a solar farm.
 * A new, low, risk of flooding.