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Thames Water shelves plans for Abingdon reservoir

Thames Water has shelved plans to build a mega £400M, 150Mm3 reservoir in the heart of Oxfordshire after revising its demand forecasts in the light of the economic recession.

The water company says it will now not need the reservoir to supplement supplies to London until 2026 at the earliest because of the collapse in the house building market. It had previously expected to need the reservoir as early as 2020.

Thames Water chief executive David Owens said the economic downturn has had a significant impact on its water demand forecasts.

“We are now predicting a slower increase in population and household numbers from those outlined in our draft Plan. This, combined with lower commercial water use and customers’ continued efforts to save water following the drought, means that overall demand for water will increase more slowly than previously forecast, particularly in the next five years,” he said.

The company has been forced to update its draft Water Resources Management Plan to reflect these changes.

Owens said additional water resources will still be needed by 2020 but that the company would promote some smaller groundwater abstraction schemes first. Thames will continue to develop the reservoir scheme to ensure that it can be operational when needed, currently indicated to be 2026.

Key revisions to Thames’ draft Plan include a substantial reduction in the forecast per capita consumption (PCC) from 157 litres per head per day (l/h/d) currently to 135 l/h/d by 2035, driven in part by a greater understanding of its customers’ reduced water use during a drought and the current economic downturn.

The plan has also been updated to reflect the success of its leakage reduction programme, which will see water lost from leaks fall from 688Ml/d to 527Ml/d between 2010 and 2020.

Thames also plans to meter all properties in its region by 2025, further cutting water use.

The gap between supply and demand has as a result been revised down to 344Ml/d from 512Ml/d in London and down to 53Ml/d from 92Ml/d in Swindon and Oxfordshire by 2035.

The Abingdon dilemma

Thames Water’s draft Plan included the proposed Upper Thames Reservoir as an integral part of its water resources strategy in order to secure supplies for both the Swindon and Oxfordshire and the London Water Resource Zones.

But the severe economic downturn and the fact that people are currently using less water, potentially as a result of water savings achieved during the recent drought and continuing dull, wet weather in the following two summers, has caused the current demand for water to drop significantly. This has been reflected in the forecasts.

Moreover, Thames has identified a number of significant uncertainties which have the potential to drive a step change in the supply demand deficit predictions and some of which are likely to be resolved within the AMP5 period. These include sustainability reductions to meet the requirements of the Water Framework Directive, improved and updated climate change predictions from the forthcoming UKCP09 scenarios, effectiveness of demand management measures, duration and severity of the economic downturn, change in weather patterns to a period of warmer, drier summers.

As a result, it does not consider it prudent to continue at current activity levels on the Upper Thames Reservoir project and the scheme is delayed by up to five years.

Early resolution of some of the uncertainties described above could drive the need for Upper Thames Reservoir and potentially bring the project forward again. As a result, the Water Resources Management Plan will be reviewed annually.

In the meantime Thames said will continue to engage with the planning process to ensure the reservoir scheme is recognised in plans for the area, and will keep its studies up to date.

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