The UK is surprisingly short of water – but more reservoirs aren’t the answer

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Despite its rainy reputation, the UK’s public water supplies are often threatened by drought and water scarcity. Shouldn’t the country do a better job of capturing and using all its rain?

In 2023, the government’s official National Infrastructure Commission concluded that the UK needs more reservoirs. It lamented that no new reservoir has been built for more than 30 years and demanded new water infrastructure for at least 1,300 megalitres per day, the equivalent of 5,200 Olympic-sized swimming pools.

But new reservoirs are not really the best and certainly not the only answer to water supply issues. A stronger focus on reusing water and demanding less of it in the first place provide a more suitable answer.

Reservoirs typically come in two forms: either as storage reservoirs above or below ground, or as reservoir lakes with a dam which is often used to generate hydropower. Many of Britain’s reservoirs were built during Victorian times and, for example, the city of Birmingham completely relies on water delivered from the Elan Valley reservoirs in Wales some 75 miles away. The vast Loch Katrine – a lake with a dam – has been the main fresh water supply for Glasgow since 1859.

Water from Elan Valley travels by aqueduct to Birmingham. Its journey is entirely gravity-powered: the gradient is just 1 in 2,300. Dave Bevan / shutterstock

Across England’s private water suppliers, there are plans for ten new reservoirs, one enlargement and multiple large pipelines to transfer water within and between different regions and water companies.

Whether these will ever be built is questionable. Building a new reservoir is not only costly and highly regulated, but local opposition is fierce. Thames Water has been trying to build a new storage reservoir south of Oxford for decades, for instance, despite objections from the local council.

Reuse and reduce

The UK should look beyond reservoirs to things like water reuse. This might include catching and filtering rainwater for instance, or cleaning water typically seen as waste. Reused water reduces the reliance on surface and groundwater supplies and could significantly address water scarcity.

The success and uptake of water reuse is evident in major regions and cities such as California, Sydney, Melbourne and Beijing. Although water reuse is developing, at the same time, the developing interest is not matched in uniform practice – for instance, according to a 2017 European Commission report, only 0.08% of urban wastewater was reused in the UK compared to 97% in Cyprus.

Reducing water demand in the first place is just as important. A report on Scotland’s climate adaptation plans says citizens need to reduce their water consumption, while the UK’s official climate change advisory body says more must be done in terms of reducing demand than on the supply side.

The UK’s biggest water user. Juice Flair / shutterstock

Importantly, demand management is not only for you in your home. Industry and especially agriculture have a role to play too – a large majority of the UK’s water use goes to industrial processes, watering crops and drinking water for animals.

Politically unpalatable

Given Britain’s per person water consumption (excluding agriculture) is among the highest in Europe, the question arises why there is not more focus on demand management.

Partly, this is because, in England at least, water companies may favour building hard infrastructure as it creates assets and thereby value for shareholders.

But it’s also because it is considered politically unpalatable to ask people to save water, especially in countries such as the UK where water is perceived to be abundant. Becoming a water-sensitive nation is hard when people so often look out the window and see rain.

We know it is possible, however. Similarly rainy countries such as Denmark use less water through a combination of public campaigns, water metering, and demand reduction technologies including water saving taps, toilets and showers. The UK could also change its building regulations so that water saving devices become compulsory in new homes.

Telling customers to save more water isn’t the easiest job for an industry whose reputation is at its lowest level ever, amid the sewage scandal and reports of high profits and CEO bonuses. Yet it is worth it as conversations with customers can re-establish and build trust. It can also provide customers with a better appreciation of the very resource we all need to survive.