Dry Weather Sewage Spills: The Hidden Impact On Businesses

The UK’s water industry is facing growing scrutiny over sewage pollution, with new figures suggesting that suspected illegal discharges during dry weather increased significantly during the first five months of 2026

According to reporting by The Guardian, water companies recorded 7,280 suspected dry-weather sewage discharges between January and May this year. That compares with 8,576 such discharges recorded across the whole of 2025.

The water industry has stressed that it is too early to classify all of the incidents as dry-weather spills. 

Nevertheless, the situation highlights a wider issue for businesses: the UK’s water infrastructure is under increasing pressure, making responsible water management more important than ever.

What is a dry-weather sewage discharge?

Combined sewer overflows are designed to provide relief when sewer systems become overwhelmed, traditionally during periods of heavy rainfall.

The problem is that some of these overflows are reportedly being activated during dry weather. The Environment Agency defines a dry-day spill as an overflow operating despite little or no rainfall on that day or the previous day.

Since 2025, water companies in England have been required to report these incidents to the Environment Agency as pollution incidents.

During dry conditions, there is less water flowing through rivers and other waterways to dilute pollutants. This means that sewage entering a river or coastal environment can have a particularly significant impact.

The Guardian reported that South West Water recorded 1,299 dry-day discharges during the first five months of 2026, compared with 2,451 during the whole of 2025. These figures have understandably attracted considerable public and regulatory attention.

Why is the UK experiencing greater pressure on its water systems?

The current situation cannot be separated from the wider pressures facing the UK’s water resources. Much of England experienced prolonged dry weather during 2026, contributing to widespread drought conditions. 

Low rainfall affects the amount of water available in rivers, reservoirs and groundwater, while warmer weather can increase demand from households and businesses.

At the same time, the country’s sewerage and water infrastructure has to cope with changing weather patterns and ageing assets.

The Guardian report notes that combined sewer overflows were originally intended as emergency systems for extreme weather. However, concerns have grown about their regular use, alongside questions about investment and infrastructure capacity.

For businesses, this should serve as a reminder that water is a finite resource and water infrastructure cannot be taken for granted.

What does this mean for businesses?

Businesses may not have any direct control over sewage discharges or the condition of the public sewer network, but they can take steps to reduce their own impact on water resources.

The first is understanding how much water the business actually consumes. It is surprisingly easy for water use to go unnoticed, particularly in larger premises or organisations with multiple sites. 

A business might know its total water bill without knowing which activities account for the majority of its consumption. A commercial water audit can help identify where water is being used and whether there are opportunities to reduce unnecessary consumption.

This could involve looking at everything from toilets and kitchens to cleaning processes, manufacturing equipment, cooling systems and irrigation, depending on the type of business.

Could reducing water use help?

Reducing consumption is beneficial for more than one reason. Using less water can reduce pressure on public supplies at a time when drought is putting resources under strain. It can also reduce wastewater volumes and potentially lower a business’s overall water costs.

Simple measures can make a difference, but larger businesses may be able to achieve more substantial savings by examining their processes in detail.

Leak detection is one obvious area to investigate. A leaking toilet, pipe or piece of equipment might appear relatively insignificant, but a leak operating continuously can waste large volumes of water.

Businesses can also consider technologies such as Automated Meter Reading (AMR). More frequent consumption data can make it easier to spot unusual usage patterns, helping businesses identify potential leaks and understand how water demand changes throughout the day.

Other organisations may benefit from rainwater harvesting, water recycling or changes to water-intensive processes. The right approach will depend on the business, its premises and how it uses water.

Does changing business water supplier make a difference?

For eligible businesses in England, the competitive water market provides an opportunity to compare commercial water providers.

Switching supplier will not change the physical infrastructure delivering water to your premises, nor will it directly determine how a water company manages public sewerage infrastructure.

However, the retailer you choose can influence the service and support you receive as a business customer.

When comparing commercial water suppliers, businesses can look beyond headline prices and consider factors such as billing, customer service, account management and support with water efficiency.

This is particularly relevant for businesses that have not reviewed their water arrangements for several years. A supplier comparison can also help businesses identify whether they are currently getting the level of support and service they need.

Why should businesses take water efficiency seriously?

The latest sewage discharge figures are part of a much bigger conversation about how the UK manages its water. There is growing pressure to reduce pollution, improve infrastructure, tackle leakage and make better use of limited water resources. 

The government has also indicated that water companies will face greater accountability over environmental performance. 

The Department for Environment, Food and Rural Affairs told The Guardian that requiring companies to report dry-day spills provides evidence that can be used to take action where performance falls short.

Businesses are likely to face increasing expectations around responsible resource use too.

In many cases, the first step is simply finding out where water is being used and whether current arrangements are still suitable.

The lesson from the latest sewage discharge figures is not simply that the water industry needs to improve. It is also that water management deserves greater attention at an organisational level.