More water to drink, pressure on drains with climate change
CLIMATE change has been predicted to bring a ‘fundamental shift’ to the workings of Guernsey Water, with hotter, drier summers, less predictable rainfall and a higher risk of droughts.
Its latest annual report shows that the trading entity is awake to the challenges of the global shift.
In his chairman’s statement, John Hollis wrote that it could not be complacent to the long planning horizon which shows increasing demand for water and the need to adapt drainage systems.
‘In aiming to provide sustainable drainage we recognise that it won’t be efficient or sustainable to adapt to climate change by simply investing in bigger and bigger drainage infrastructure,’ he said.
‘We must maximise the capacity we already have by dealing with rainwater in a different way.
‘This will require a fundamental shift in the way we engineer our drainage systems, but by using more natural methods in the right places, we can better adapt to climate change whilst also improving the urban fabric and supporting biodiversity.’
As the effects of climate change kick in over the next few decades, the problem is expected to be one of extremes, with either too much water in the system, or too little.
Total rainfall during 2020 was 25% above the average and there were no water use restrictions.
A wet October and December meant that water resources were full by the end of the year.
While that was positive for water resources, it put considerable strain on the drainage systems and cesspit collection service.
The board of Guernsey Water is considering how it will need to develop the water capture and storage systems to ensure resilience to severe drought in the future.
It has also confirmed that engineering a solution to future drainage capacity in St Peter Port was likely to be ‘too costly and disruptive’.
Therefore the focus has shifted to the drainage systems across the island that flow into it, particularly those that are already overloaded during extended periods of heavy rainfall.
Water customers in England have greater protection from drought than customers in Guernsey, and this is another issue under consideration.
Guernsey Water managing director Stephen Langlois said it was evaluating whether to increase the island’s drought resilience.
‘This means we will need to bring forward the planned review of our water resources and drought management plan to 2021.
‘The outcome of this review will also enable us to complete the ongoing development of our water transfer strategy, which will determine whether we need to invest in retaining several of our smallest reservoirs at significant cost for marginal water resource gains.’
