Jersey’s desalination plant has cost more than £600,000 this year – and a climate change expert warns bills could rise with hotter and drier summers.
The machine, which makes drinking water from the sea, was put into operation in July amid “extremely dry” weather, before the ban on the water hose.
The desalination plant lasted 77 days, costing £616,000.
Jersey Water said the plant was customer-funded, but not linked to next year’s tariff increase.
After heavy rain, which increased reservoir levels, the plant, which runs at a cost of £8,000 a day, has since been deactivated.
Jersey Water said the plant’s running costs were “not included” in next year’s 6% tariff increase, equivalent to around £23 a year.
However, he said “specific adjustment” may be needed in the future if it needed to be operated more frequently or for longer periods.
Professor Liz Bentley, chief executive of the Royal Meteorological Society, said desalination was “one element” of dealing with drought, particularly for island states.
“Desalination is very expensive and there is also an environmental cost.
“There is energy consumption to remove the salt from the water and that contributes to more greenhouse gases in the atmosphere.”
Predicting “hotter and drier summers” ahead, she said Jersey’s “extreme” summer in 2022 would be considered “typical” by mid-century.
Describing the process as “financially and environmentally expensive”, she said it would be important in the future to look at sustainable sources of energy for plants like the one in Jersey.
In Jersey Water’s 2018 annual report, it stated: “The relatively low reservoir storage capacity combined with the island’s dependence on rainfall means that Jersey’s water resources are particularly susceptible to periods of drought.”
In 2021, the plant at La Rosiere on the south-west coast of the island was only used for 14 days for a “performance trial”, at a cost of around £112,000.
Between 2011 and 2018, the plant, powered by Jersey Electricity, was not needed for drought conditions. It was then run in 2018 and 2019 to increase water supply.
A spokesman for Jersey Water said the running costs of the desalination plant and the loss of revenue through the pipe ban have not been taken into account in the tariff increase.
She said that they would “finance in this case from reserves” – paid by customers.
She said the plant would “remain idle for the foreseeable future” but that they would be “keeping a close eye” and would be reviewed as necessary.
“Going forward we will probably start the pre-treatment phase every year to make sure it is ready to run when needed.”
Regarding future tariff increases, she said: “A separate adjustment may be necessary in the future if the operation of the desalination plant becomes more frequent or if the duration is extended.”
The factory has no permanent staff but engineers are there every day to supervise its operation.
The Government of Jersey is a majority shareholder in Jersey Water.
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