Southern Water, Hampshire, UK: Planned augmentation of Havant Thicket Reservoir
The Hampshire Water Transfer and Water Recycling Project sets out to help protect the River Test and River Itchen, two of Hampshire’s rare and sensitive chalk streams, by reducing abstractions and providing a new sustainable water source for the county.
Following reductions in the amount of water Southern Water can take from these rivers and their associated aquifers, the company faces a potential shortfall of 192 million litres (50 million gallons) a day in Hampshire in a 1-in-200-year drought – around 80% of the Southern Water current supply. The Project is part of a suite of measures being undertaken by Southern Water under its Water for Life – Hampshire programme, including fixing leaks, improving water efficiency and working with farmers and landowners to reduce the impact of pesticides and fertilisers on watercourses.
The Project replaced a proposed desalination plant as the preferred option for a major infrastructure solution at the end of 2022. This followed an extensive optioneering process that considered environmental, planning, social, legal and policy, value, supply and demand and future needs metrics, as well as a public consultation on desalination. The Project was selected as the optimal solution to make up the largest proportion of the shortfall.
The Project comprises a water recycling plant and associated pipework and pumping facilities. Treated wastewater from the existing Budds Farm Wastewater Treatment Works would be transferred to the water recycling plant before being transferred via a new underground pipeline to the planned Havant Thicket reservoir, which is being funded by Southern Water and built by Portsmouth Water. The purified, recycled water will blend with the spring water in the reservoir and be transferred via a new pipeline to the Otterbourne Water Supply Works, where it will be treated further to become drinking water. The reject water stream produced by the water recycling plant will be released 5.7km into the Solent via the existing long sea outfall from Budds Farm.