Half of England has officially entered drought, intensifying concerns over potato yields, tuber size and crop quality as growers face restrictions on water abstraction during a critical stage of the 2026 growing season.

The Environment Agency said seven areas were now in drought: East Anglia; Hertfordshire and London; the Thames Valley; Hampshire and the Isle of Wight; Devon and Cornwall; the West Midlands; and Wessex, covering Dorset, Somerset, Wiltshire and South Gloucestershire.

These regions include several important potato-producing areas and processing supply chains. The drought declaration comes as irrigation demand remains high and farm reservoirs are being depleted rapidly, leaving growers increasingly exposed if substantial rainfall does not arrive during August.

Potatoes are particularly vulnerable to water stress during tuber initiation and bulking. Inadequate or irregular water supplies can reduce marketable yield, restrict tuber size and create quality defects that affect whether crops meet specifications for the fresh, crisping and French fry sectors.

GB Potatoes recently estimated that a potato crop requires approximately 350mm of water during the growing season, supplied through rainfall, soil reserves and irrigation. The organisation warned that increasingly unreliable access to water could reduce British production and increase the industry’s dependence on imports.

“Water is not an optional extra for potato production. It is fundamental to maintaining the crop we grow today and absolutely essential if we want to increase British production in the future,” GB Potatoes Chief Executive Scott Walker said.

The Environment Agency described the situation as a rapidly developing “flash drought”, caused by exceptionally low rainfall combined with prolonged high temperatures. July received only 7% of its expected rainfall, falling to 1% across southern England, while three heatwaves included 12 consecutive days with temperatures above 30°C.

Soil moisture deficits reached record levels for the time of year across central, south-eastern, south-western and north-eastern England. Around 78% of rivers were classified as below normal or lower, while reservoir storage had fallen to 75.3%, approximately 7.4 percentage points below the seasonal average.

Low river flows have resulted in 1,506 restrictions on abstraction licences. The Environment Agency said farm storage reservoirs had declined rapidly, creating concerns about irrigation availability for the remainder of the season.

For potato growers, reduced access to water could limit the ability to maintain steady soil moisture during bulking. It may also complicate late-season crop management, as excessive soil moisture deficits before haulm destruction can leave tubers dehydrated and more susceptible to bruising during harvesting and handling.

The effects may extend beyond total tonnage. Uneven crop development could result in greater variation in tuber size, while reduced bulking may affect the proportion of potatoes meeting processor specifications. The consequences will vary considerably between farms depending on planting date, soil type, variety and access to stored irrigation water.

“A second consecutive summer drought is an exceptionally serious situation and one that will have long-lasting impacts on our environment, wildlife, and the economy,” said Helen Wakeham, the Environment Agency’s Director of Water and Chair of the National Drought Group.

“We want everyone to stay safe and hydrated during the hot weather but every drop we can save is a drop more for nature and agriculture.”

The Met Office said occasional unsettled periods were possible during early August but there was little indication of the widespread and sustained rainfall required to significantly improve conditions.

The drought follows similarly dry conditions in 2022 and 2025, making 2026 the third drought year in England within five years. For the potato sector, the latest restrictions reinforce industry calls for faster approval of on-farm reservoirs and policies allowing growers to capture surplus winter rainfall for use during increasingly dry summers.