Despite spells of heavy and at times torrential rain in recent weeks, the relatively dry weather in 2019 prompted the usage of the desalination plant towards the end of September.
According to Jersey Water’s newly published annual report there was 18.8% less rainfall in the Island than the five-year average during the period.
It says: ‘The dry winter and summer meant ground-water levels did not replenish and reservoir levels did not reach full until March 2019 and then only for a short while, before declining over the spring and summer to end the period at 58% full, well below the average for that time of the year.
‘Operation of the desalination plant commenced on 23 September 2019, for the purposes of topping up reservoir levels and testing recent modifications to the plant.’
Responding to the report, Jersey Water chief executive Helier Smith once again called for the Gigoulande Quarry at the top of St Peter’s Valley to be converted into a reservoir to prevent future shortages.
He says: ‘One of the key focuses on the period has been the development of the Water Resources Management Plan which has highlighted that, if no action is taken, in severe drought years there will be a growing shortfall between the demand for water and the water available for use driven principally by the effects of climate change and predicted population growth.
‘We are looking at a range of options to both reduce demand and increase water resources. Our Island Plan submission made the case for a new reservoir on the site of Gigoulande Quarry that would provide much-needed additional storage capacity for generations to come.’
He added: ‘As an island with only 120 days of water storage when full, we are vulnerable to water shortages and drought. Over the winter period, we lose a considerable amount of water to the sea simply because we have insufficient capacity to store it. The potential to repurpose the quarry as a water-storage reservoir provides a once-in-a-lifetime opportunity.’
