In line with climate-change predictions, the Island lurched from long spells of dry and sunny weather – including the warmest period since the famously hot summer of 1976 – to some of the wettest months since records began.
Experts say Jersey now needs to ensure that it has enough capacity to store rainfall in the wettest months to ensure that it can meet demand during what are expected to become increasingly dry summers.
The figures, released by Jersey Met, show:
- Last year was the wettest since records began in 1894, with a total of 1178.4mm of rain.
- It was the second-warmest and second-sunniest with an average temperature of 13.2°C, just behind 2014.
- Spring – March, April and May – was the sunniest and warmest on record.
- Seven of the ten hottest years on record have happened since the year 2000.
- And two months last year – October and December – were among the five wettest months of all time.
John Searson, Jersey Met’s principal meteorologist, said: ‘Last year’s weather was consistent with what we would expect with climate change.
‘The warmer the air, the more moisture it can hold and, as a consequence, there is a greater chance of heavier rainfall.
‘Therefore, greater rainfall totals don’t necessarily mean less sunshine across the year.
‘The indications are that we will see drier summers and therefore a greater risk of drought, but with wetter winters. So it’s really a question of whether we have enough water storage as we go into the summer months.’
Two years ago, Jersey Water published its Water Resources Management Plan, which set out various options for securing future supplies in the face of a growing population and increasingly unpredictable climate.
The report stated that, based on current estimates, if no action was taken, demand for water would exceed supply by 8.2 million litres a day during severe drought conditions from 2045.
The company analysed a number of options, including increasing the height of the dam wall at Val de la Mare reservoir, increasing the capacity of the desalination plant, using more quarries and streams and building a new reservoir.
It is now planning to push forward with two options: increasing the output of the desalination plant from ten million litres per day to 15 million litres by 2025 and possibly using La Gigoulande quarry in St Mary, which is currently used by Granite Products.
Mark Bowden, asset manager at Jersey Water, said: ‘The desalination plant is really an insurance policy which we would only use in the event of a severe drought, as it is quite expensive to operate. What we really need to do is increase our level of storage and we are looking at utilising this once mineral extraction stops. We have perhaps a five-to-ten-year horizon for this but it is tied up in the Island Plan and the Island’s mineral strategy.’
