Although it may sometimes seem that the South-East has ample rainfall, this is far from true. The region, which includes the area supplied by Thames Water, is in fact categorised by the Environment Agency as 'seriously water stressed'.
Although the weather is often damp, total rainfall levels are not high. London receives less rainfall in an average year than cities which are generally perceived as being much drier, such as Rome, Dallas and Istanbul.
The capital also gets less rainfall than Florida and only about half as much as Sydney. In addition, the region's rainfall is spread almost evenly across the year, with February being the driest month.
Summer rainfall provides little benefit to water resources due to evaporation and transpiration by actively growing plants.
The year 2009/10 was mainly influenced by the contrasting dry summer followed by a relatively wet but cold winter. The Thames catchment experienced a relatively dry summer in 2009, with 79 per cent of average rainfall recorded.
This was followed by a wet winter, which saw 123 per cent of average rainfall. Overall, rainfall for the year was 103 per cent of average (EA provisional data). The distribution of the rainfall was noticeably different from west to east, with the Cotswolds in the west experiencing a wetter summer at 94 per cent than the Lee catchment in the east, where 80 per cent was recorded. This trend continued into the winter, with 124 per cent and 112 per cent of average rainfall respectively.
The dry summer contributed to an increase in demand, as did the prolonged spells of cold weather, which caused a significant increase in leakage.
We worked hard to reduce these leakage levels, while also completing a number of water resource schemes, the most significant of which is our new Gateway Water Treatment Works in east London. This means that, on average, there is a now a surplus of available resources over demand across our area.
About 77 per cent of our water comes from rivers, and the remaining 23 per cent from underground sources. Both of these sources are regulated by the Environment Agency (EA), which issues licences limiting the amount available to us. In 2009, we achieved 99.90 per cent compliance with our daily licences and 100 per cent with our annual licences.
Pressure on water resources is likely to continue to grow, due to climate change, the increasing population in our area and more people living alone. There will also be potential reductions in the amount of water available for us to take from rivers and groundwater sources.
The Government's national target is to reduce the amount of water our society uses to an average of 130 litres per person per day by 2030.
In 2009/10, household usage in our region was 163 litres per person per day. This was an increase from the previous figure of 157.5 litres, and was in line with the better weather seen in summer 2009 compared with the year before.
Every five years, we are required to produce a Water Resources Management Plan, which sets out our forecasts for future demand and available supplies. It also explains how we intend to maintain the balance between supply and demand for water for the next 25 years.
We published our draft plan in May 2008, after which we held a public consultation, subsequently reviewing our proposals in the light of feedback and other factors, such as the economic downturn. Our revised plan focuses on managing demand over the next ten years – for example, by reducing leakage and promoting wise use of water, with new resources required in the longer term.
We aim to:
Reduce leakage to 406 million litres per day from levels of 670 million litres per day at the end of 2009/10. This will build on the work we have already done to reduce leakage by 27 per cent over the last five years
Carry out a programme of targeted and progressive compulsory metering to increase the proportion of customers with meters. By 2025, our aim is that 80 per cent of customers will have meters
Despite these measures, we believe that in the longer term we will need a new strategic regional water resource in order to maintain supplies. Our proposals for an Upper Thames Reservoir in Oxfordshire therefore remain part of our plans to meet the need for water in parts of the Thames Valley and London. Our view is that we will require a new reservoir from 2025/2026.
We are continuing to explore innovative sources of water - for example, by opening our new desalination plant in east London. This includes running a pilot plant at a site in north-east London which is taking treated effluent and putting it through a further treatment process to produce drinking water.
In 2009, the Government announced that a public inquiry would be held into our Water Resources Management Plan, which began in June 2010. At the time of writing, we are awaiting the final decision on what changes, if any, will be required to our plan.
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