Heat exposes England’s fragile water network

Thousands of households across southeast England were left without water or struggling with low pressure after record-breaking temperatures collided with a dry spring, placing renewed scrutiny on the resilience of Britain’s ageing water network and the performance of South East Water.

The disruption reached more than 20,000 people at its height, with about 8,000 affected in Whitstable, Kent, where residents queued for bottled water and some businesses shut their doors during a busy holiday period. Areas of Kent and Sussex also reported intermittent supply, weak pressure and emergency water stations as demand surged across the company’s network.

South East Water said exceptionally high usage had drained local storage faster than it could be replenished, despite increased output from treatment works and round-the-clock tanker operations. The company asked customers still in supply to use water only for essential purposes such as drinking, cooking and washing, warning that non-essential use would slow the recovery of service to homes on higher ground and at the edges of the system.

The crisis followed two consecutive days of extraordinary heat. Kew Gardens recorded 34.8C on 25 May, provisionally breaking the UK records for both May and spring, before the same site reached 35.1C the next day. Heathrow also recorded 35.0C. The previous May and spring benchmark, 32.8C, had stood from 1922 and 1944.

The weather arrived after a notably dry start to spring. England received 48.5mm of rain in March, equivalent to 83 per cent of the 1991-2020 average, followed by just 21mm in April, or 38 per cent of the long-term average. East and southeast England recorded their driest April since 2011, while soil moisture deficits grew quickly across the region.

That combination left water companies facing intense pressure from household use, garden watering, tourism demand and commercial activity. South East Water said demand on one day reached about 670 million litres, nearly 100 million litres above the seasonal norm. The spike came at a time when some local reservoirs were already low and the network had limited flexibility to move water quickly to pressure-hit communities.

The outage has intensified anger among residents and local businesses already familiar with supply failures. Whitstable, a coastal town heavily dependent on visitors, saw hospitality operators forced to close or limit service as taps ran dry. Residents complained about poor communication, long waits at distribution points and uncertainty over when normal supply would return.

South East Water has faced regulatory pressure over its handling of repeated interruptions. Ofwat proposed a £22 million penalty this year after finding failures linked to supply disruptions between 2020 and 2023, affecting more than 286,000 people. The regulator said the company had not maintained adequate resilience in service reservoirs, boreholes and major pipes and had struggled during periods of high demand and extreme weather.

The company’s leadership has also come under political scrutiny. Parliamentary criticism of South East Water’s performance led to senior resignations, while MPs and local authorities have pressed for clearer accountability, stronger contingency planning and faster investment in assets that can withstand hotter summers and more volatile rainfall.

The wider sector faces similar questions. Water companies in England and Wales are under pressure over leakage, debt, dividends, executive pay, sewage spills and the pace of infrastructure upgrades. Public frustration has grown as consumers face rising bills while utilities argue that large-scale investment is needed to renew pipes, build reservoirs, expand transfers between regions and protect supplies against climate stress.

The government has set out plans for major private investment in water infrastructure and tougher oversight of company conduct. Its wider programme includes stronger enforcement powers, tighter rules on executive bonuses and long-term work to reduce daily household consumption. Regulators and ministers have also warned that England could face a multi-billion-litre daily supply shortfall by the middle of the century without action on demand, leakage, storage and climate adaptation.

Climate advisers have warned that hotter, drier spells will become more frequent and more severe as the climate changes, increasing risks to homes, farms, transport, energy systems and water supplies. They have called for far higher spending on adaptation, including measures to protect public infrastructure, manage water scarcity and reduce damage from heat, flooding and drought.