Water for the Company is principally derived from a chalk aquifer. Supplies are drawn from wells and boreholes throughout the Company’s supply area, from a series of natural springs in Havant and Bedhampton and from an abstraction on the River Itchen.
The critical demand period for water is from the end of May to the end of July when additional demand results from garden watering, increased horticultural needs, increased personal washing and the influx of holiday visitors to the seaside resorts.
It is predicted that the demand for water will increase over the next 25 years and that there will be a water deficit by 2020/21 due to the following factors:
- Lifestyle changes and lower occupancy households - As a result of an increase in lower occupancy households (which have a greater water demand per individual), the per person consumption is expected to increase;
- Climate change - Predicted changes in the climate (such as hotter summers) will mean that people will increase their water consumption;
- Environmental considerations - The water environment provides many important habitats for wildlife, which need to be preserved. Limitations are placed on the abstraction from these sensitive sources by the Environment Agency through the powers they have from the European Habitats Directive;
- Population increase - It is predicted that the population of the Portsmouth Water supply area will increase by an additional 50,000 people by 2035
A study by the Water Resources in the South East (WRSE) Group, headed by the Environment Agency, indicated potential shortages over much of the South East by 2025.
Water Resources Management Plan
Every five years the Company produces a water resources management plan, which sets out how supply and demand will be managed for the next 25 years. The Water Resources Management Plan of 2004 and 2009 identified a deficit in the supply of water required to address the demand predicted by 2020/21.
To address the predicted deficit of water the company has adopted the so called “twin track” approach, in line with government advice:
- Examining means of reducing overall demand for water (through, for instance, efficiency measures);
- Considering additional water resources (such as a reservoir or abstraction borehole)
A number of options were evaluated for meeting the additional demand. The final strategy combines a number of measures, including:
- Reductions in leakage;
- Compulsory metering over a period of time;
- Continued promotion of water efficiency measures;
- The construction of a washwater recovery plant at Farlington Treatment Works;
- Construction of the Havant Thicket Winter Storage Reservoir
The construction of the reservoir is the most significant element of the strategy in terms of the additional capacity it would provide. The reservoir will be approximately one mile long and half a mile wide and will have a capacity of 8,700 million litres.
Statement of need
A statement of need for the reservoir and the rationale behind the demand requirements of the catchment area will be provided within the Environmental Statement, which will be submitted with the planning application for the proposed reservoir. The needs assessment will draw from the Company Water Resources Management Plan (WRMP).