Climate change: Could Kent’s taps run dry as we experience hotter, drier summers and milder, wetter winters?
Published: 05:00, 03 April 2024
Updated: 10:50, 03 April 2024
Last year, before summer had even officially begun, a hosepipe ban was introduced across many parts of the county.
South East Water’s mid-June move, following a period of dry, warm weather, surprised many. After all, just the year before, we had seen a record-breaking heatwave, prompting fears that if there was a repeat, just how would our water supplies hold up?
Fortunately for the water companies, the summer of 2023 was something of a damp squib; water sources upon which they (and we) rely were topped up, beneath gloomy skies, and those water restrictions were lifted as August dawned.
Yet it begs the question – if the impact of climate change ushers in the longer, drier and hotter summers predicted, is there a danger of our taps running dry?
It is, for one of the richest nations in the world, an unlikely scenario. But then climate change is proving adept at rewriting the rule book – and the threat is very real.
Dr Laura Dawkins is an expert scientist in climate risk and resilience at the Met Office. She explains: “Broadly speaking, there is a risk of increased hot and dry spells, but also more intense rainfall which may impact water resources across the UK.
“Heavy downpours are more likely in warmer climates as warmer air holds more water.
“An important area of our work is understanding how climate change will impact the water cycle, as well as water availability for human use.”
All of which sounds promising in terms of future supply. More water falling from the skies equals more water for us to drink, bathe in and clean our cars with, right? But there are complications.
“Water and climate change are very much linked,” says Samer Bagaeen, professor of planning and resilient systems at the University of Kent’s school of architecture and planning. “Extreme weather events are making water more unpredictable.
“The challenge is around water infrastructure and how you manage water supplies. It is the overall water cycle which is feeling the stress of climate change.”
The vast majority of the water which pours through our taps comes from beneath our feet in what are known as aquifers.
This is where water soaks through the ground and then collects in a layer of permeable rock which can contain or transmit water. Kent is heavily reliant on two – the Chalk and Greensand aquifers. Fortunately for us, both are two of the most significant in the UK.
For example, Southern Water says 70% of its water comes from underground aquifers, 23% from our rivers and just 7% from reservoirs.
It’s a similar story at South East Water where 73% comes from aquifers, 19% from rivers and reservoirs and 8% imported from neighbouring water companies.
The water cycle, referred to by Professor Bagaeen, is the amount of time it takes for that water to be collected, treated and then pumped around the network of the handful of water companies serving the county.
And that varies considerably.
“For water in rivers and reservoirs,” explains a spokesman for South East Water, “we can theoretically benefit from rainfall within a few hours of it falling and running off the ground into streams and rivers where we abstract it from, treat it and then pump it into underground treated water service reservoirs which are used to supply customers from.
“Typically, it might take 24-48 hours from rainfall to tap for these types of surface water sources. For groundwater sources, it can take weeks if not months for rainfall to infiltrate through the soil and rocks into the aquifer before it is then abstracted via a borehole or well. Often in summer, rainfall won’t even reach the customer tap because it evaporates or is taken up by plants.”
Well, you might think, given the amount of rain we get, surely they are all regularly topped up? And the good news is yes, they are. The only fly in the ointment is that the government has issued legislation to ensure water companies are protecting the environment and not causing any long-term damage to these crucial underground water sources.
South East Water, for example, is expected to have to reduce the volume of water from aquifers by between 5-10%.
But climate change is throwing a spanner in the works too. Traditionally, the aquifers and reservoirs would be filled up during the winter and then be topped up by summer showers as demand peaked. Now, though, milder, wetter winters are seeing far more rain, while summers are tending to be drier and hotter.
Nick Price is head of water resources at South East Water. He explains: “I know we live in a wet country, but this winter we have far too much water. When you only have a certain amount of storage, when we go into a summer or dry period, that storage can drop quite quickly.
“To ensure we can maintain supplies to customers is what we call our supply-demand balance which, in simple terms, is a forecast of how much water is needed against how much water there is available.
“Climate change is putting demands on both sides of the equation - rainfall is becoming more unpredictable and intense and, as we go longer without rainfall, it's vital our supply can adapt to how we capture that rainfall and store more water.
“Reservoirs are a good way to capture the higher winter rainfall we are seeing.”
To that end, it is hoping to finally deliver on plans for a reservoir at Broad Oak in Canterbury. Discussed for close to 50 years, South East Water insists it will be built by 2033 – at a cost of some £130m.
Adds Nick Price: “That scheme is designed to capture the high flows in the River Stour when we experience them in future winters and store them.”
But, Prof Bagaeen asks, will it be enough: “The question is have we taken advantage of all that excessive rainfall? Because we're not necessarily investing in the infrastructure, that is not helping protect our long-term resilience.”
The handful of water companies which supply Kent’s water have struggled to cover themselves in glory over recent years due, in part at least, to the disgraceful sewage discharges into our seas and rivers, for which the likes of Southern Water has come in for particular criticism – a problem caused, at least in part by the changing climate bringing with it heavier downpours putting strains on ageing infrastructure.
But in addition, there is the issue of a steadily growing population not to mention the perennial problem of leaks – with Prof Bagaeen describing the approach to them as similar to that of how we handle potholes – “it’s reactive, not proactive”. He adds: “Their target is something like reducing waste and leaks by 20% over a 10-year period. That's probably not an ambitious enough target. They need to be working a lot harder.”
The infrastructure he refers to includes the ability to share the region’s water supplies between the different companies. In other words, if there’s a strain on water supplies in one part of the county, having the ability to ‘import’ water from a neighbouring firm.
Nick Price at South East Water says this does currently happen to a limited degree – but that more needs to be done.
“Within Kent, there are several water supply companies so each has its own network and ability to move water around their own area. But there is existing interconnectivity between companies as well.
“So we, for example, have several connecting points with Southern Water where we share water. In some cases we import water they produce and in other places it's the other way around.
“That's been in place for a number of years. What we're now doing as a South East region, with the six water companies, is more work in ignoring company boundaries and that if we want to provide the best resilience and best water supply for the whole region, how would we connect the area up?
“That has proved helpful in identifying some new options.”
Expect much of that additional – considerable – cost across our water network to be funded by hikes in our bills.
Adds Nick Price: “For a lot of water companies, including ourselves, it’s been a challenging last two or three years.
“A lot of that is weather-related. We’re starting to see the effects of climate change very clearly now with the very high temperatures in summer - these heatwave events. In the winter we've had cold periods and then a sudden increase in temperatures which can cause havoc within the pipe network which can cause lots of leaks to occur very quickly.
“We do recognise our performance around those incidences hasn't been up to scratch and we've had customers experience short periods of their water supply not working.
“We are, as an industry, heavily regulated. Those regulators have all set high expectations of the standards we need to achieve and we are committed to improving our resilience to these sorts of events by improving our performance on leakage - an issue which comes up time and time again. If we can get on top of leaks that helps improve our reputation and is the right thing to do to make sure we're using every drop of water as carefully as we possibly can.
“In the long term, the key challenges we face are climate change and population growth and a third element, which is a big driver of our plans over the next five to 15 years, is the environment.
“That's ensuring we are adapting to the climate and protecting the environment in the best possible way.”
A bit like with Britain’s railways, improvements are limited without significant financial outlay – but with the threat posed over the coming decades by our changing climate to that most essential resource, water, it’s time those we have entrusted to ensure the taps never run dry step up to the mark.
But also that we, as consumers, alter our approach to water usage.
Nick Price concludes: “We need to engage with customers to ensure everyone realises that water is finite and every drop has to come out of a reservoir, a river or an aquifer. We need to make people understand the whole water cycle relationship.”
So, should we be concerned looking further ahead?
*Read more of our Spotlight on Climate Change features here
“Yes,” says Professor Bagaeen, “but not to the extent that we panic. We should be concerned as these are serious issues and we just have to hope people are looking at all these challenges in a joined-up way.”
For better or for worse, in the water companies we must place our trust to prevent our taps running dry.
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Chris Britcher