The water deficit, in one place

Where the water comes from

Abbots Langley sits over a chalk aquifer, and its river — the River Gade — is a chalk stream. Chalk streams are among the rarest river habitats on Earth: around 85% of the world’s are in England, and Hertfordshire holds roughly 10% of England’s ~220.¹ They are fed mostly by groundwater, which is why the chalk beneath our feet is the river.

The district is officially classed as an area of serious water stress.² The River Gade is already rated “poor” and over-abstracted — and after restoration work, a 2021 fish survey found it “near desolate” before recovering to a handful of trout by 2025.³ It is a river that can come back — but only if it is given the water to do it.

Right now, today

This is not a future risk. As this is written:

• Abbots Langley is under a legally enforced hosepipe ban. Affinity Water’s Temporary Use Ban — made under the Water Industry Act 1991 — covers its Central region including postcode WD5. It was announced on 10 July 2026, enforced from 10 July 2026, and remains in force. It has since been extended to the company’s East region too.⁴
• The Environment Agency declared drought across Hertfordshire and North London on 29 July 2026, and the area is still in drought. Its latest weekly report has 11 areas in drought — parts of four now in severe drought, and Yorkshire added on 9 October — around 30 million people under restrictions, and England’s reservoir storage at 54%, more than a fifth below average, with 18 reservoirs less than half full and 11 classed as exceptionally low.⁵
• It followed the driest July on record. Hertfordshire had its driest July since 1871; a “flash drought” was declared; groundwater levels fell at every indicator site. Chalk aquifer sites are now all normal-or-lower, with a growing number notably or exceptionally low.⁶
• 2026 is worse than 2025. Confirmed drought and dry-weather incidents this year (411) exceed the totals for 2025 (321) and 2022 (380).⁵
• September was the third month in a row of below-average rain. Three-quarters of England’s reservoirs or reservoir groups are now classed as notably or exceptionally low, and the EA’s seasonal outlook is for a wetter-than-normal October–December.¹⁸
• Severe drought was declared on 15 October. Parts of Cornwall, Devon, Dorset, Somerset, East Sussex and West Sussex moved into severe drought — the first time under the current classification system — as around 78% of England sat in drought, Wimbleball and Ardingly reservoirs fell to roughly 15% and 19% full, and drought orders were granted to South East Water and South West Water.¹⁹
• Business restrictions are coming into view. South West Water’s application for a non-essential use ban drought order (submitted 6 October) would cover Exeter, Exmouth, Crediton, Sidmouth, Tiverton and parts of West Dorset including Lyme Regis — restricting commercial vehicle washing, cleaning business premises and equipment, watering commercial plants, dust suppression and non-domestic pools and ponds. Households are unaffected and the hosepipe ban remains. Wimbleball was at 18% when the application was lodged and 16% by 21 October²³, and the Environment Agency warns the South West could remain in drought into spring 2027.²²
• Leaks are still going unfixed. The BBC reported residents in southern England waiting months for leaks to be repaired despite severe drought — one Devon footpath had turned to mud. South West Water said it had repaired more than 26,700 leaks in 12 months, about 30% of them linked to customers' supply pipes. On 23 October a burst main flooded Wealdstone High Street in Harrow — inside Affinity Water's own area — closing the road while engineers attended.²¹²⁵
• Water company bosses were called in, and the government widened its drought powers. On 19 October the National Drought Group heard from water company chief executives about measures including sending less water from reservoirs into rivers, cutting pressure overnight where appropriate and moving water between networks. Separately, DEFRA and the Environment Agency issued a direction letting the EA reduce river releases or vary abstraction limits in severe-drought areas. Drought permits have been granted to South West Water and South East Water (Wimbleball into the Exe, Ardingly into the Ouse), Wessex Water is preparing seven more, and non-essential-use-ban applications from South East Water, South West Water and Southern Water are with the Environment Secretary. The EA says at least 120% of average rainfall is needed over six months to be out of drought by spring.²⁰
• A wet week did not refill anything. In the week to 20 October, two-thirds of England’s reservoirs lost water despite a second week of rain. National storage is 54%, about 22% below the long-term average, with 18 reservoirs under half full and 13 exceptionally low — including Ardingly and Wimbleball. England has had 52% of its October rainfall and the south-west just 43%; groundwater keeps falling. Storm Austen arrives today with an amber wind warning in the far south-west, and the EA expects more rain on Monday and Tuesday.²⁶

Figures as of the Environment Agency’s weekly drought report for 16–22 October 2026 (published 23 October), the September 2026 monthly summary (13 October), the severe-drought declaration of 15 October, and the 20 October drought direction. England has had 52% of its October rainfall; the National Drought Group next meets on 28 October.

The squeeze: less water, not more

The direction of travel in this catchment is the opposite of growth. The Environment Agency is unable to grant new abstraction licences from surface water and most groundwater here.⁷ In the Gade valley, Affinity Water is reducing abstraction by 6.4 million litres a day to protect the chalk stream.⁸

Meanwhile demand is up about 20%; the Central region received just 1% of its average July rainfall; and the company warns it may have to “stop or limit how much we take” from some sources before the year is out.⁹

The company’s own Water Resources Management Plan is built on cutting use and finding new supply — but admits that demand management “won’t be enough”, and the first major new supply schemes are not due until the 2030s and 2040s.¹⁰ Less water available, stricter standards: that is the plan the Local Plan must fit around.

Downstream: the sewers are already full

Wastewater matters as much as supply. The works that take Abbots Langley’s sewage — Maple Lodge — serves around 500,000 people and can receive up to 300,000 cubic metres a day, discharging to the Grand Union Canal and the River Colne.¹¹

• The council’s own Infrastructure Delivery Plan records Maple Lodge operating at 97.7% of permitted flows (2020–23) and “sometimes overwhelmed resulting in overflows”.¹²
• Its event monitoring recorded 124 storm spills lasting 1,916 hours in 2024 (about 80 days of cumulative spill time); in Storm Henk alone it discharged for more than 38 hours.¹³
• A promised AMP7 storm-storage upgrade had not been delivered as of January 2026. The large AMP8 replacement — a contract worth up to £280m — is still in its design phase and runs to March 2030.¹⁴

So the extra foul flow from 1,300 homes and a 96 MW data centre would arrive at works that are already spilling, while the plan’s own water assessment simply assumes the existing works can cope.¹⁵

The unknown at the centre

Here is the number nobody has published: the water demand of the 96 MW data centre already approved at Bedmond Road.¹⁶ Data centres are water-hungry, and this one is the single largest new user beside the site — yet its potable demand is not in the public record.

The plan itself tells the housing developer to account for it, but no combined water budget for the catchment exists, and there is no cumulative assessment of the homes, the data centre and the other schemes together. The council’s own evidence calls these catchments “highly sensitive to the cumulative impact of development” — and then assesses the sites one by one.¹⁷

That gap is national, not local. The Environment Agency told the Environmental Audit Committee that the evidence base “remains incomplete, because data centres are not required to report site-level water use” to the regulator — the sector is under 1% of public supply nationally, but “an individual development may be significant locally” — and suggested the largest non-household customers publish their usage and say what they are doing to become more efficient.²⁴