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Surface drainage charges for businesses

Local water companies are key to managing surface water drainage. In urban areas, roofs, roads, and pavements do not absorb water, so when rain falls, the water must be directed into drains and sewers and eventually into a stream or river.

Urban areas can quickly flood without drainage or when drainage is blocked, damaging properties and endangering safety.

Water companies spend over £600 million each year maintaining surface drainage. This guide explains how British businesses are charged for surface water drainage.

💡Recent controversy surrounding sewage discharge into rivers prompts significant investment in drainage and sewer infrastructure improvements.

What is a surface drainage charge?

Local water companies are paid for their surface drainage services by homes and businesses in the area.

According to Ofwat rules, if rainwater falling on a property drains into a public sewer, then the occupant of that property will pay a surface drainage charge through their water bill.

Why do businesses pay surface drainage charges?

Commercial properties, such as business parks, airports, or distribution centres, have large surface areas, meaning local drainage systems must have a higher capacity.

British businesses, therefore, contribute to a significant portion of the overall maintenance of the drainage infrastructure.

This next section will explain how businesses pay for surface drainage within business water rates.

How is the surface drainage charge calculated?

The commercial water market is deregulated, meaning surface water drainage charges are levied by business water suppliers rather than local water companies.

They way surface drainage charges appear on your bill depends on the location of your property. Here are the different types of surface drainage charges for commercial properties:

Area-based surface drainage charge

Local water companies: Northumbria Water, Severn Trent Water, United Utilities, and Yorkshire Water.

These water companies charge separately for surface drainage based on your property’s area (in square metres).

Rateable value based surface drainage charge

Local water companies: Scottish Water

Scottish Water charges for surface drainage separately, using the rateable value of each property.

Included within standing charge

Local water companies: Anglian Water, Southern Water, Thames Water, and Wessex Water.

These local water companies do not charge for surface drainage separately. Instead, the drainage charge is included within the wastewater standing charge, calculated based on water meter size.

Included within volumetric charge

Local water companies: South West Water

South West Water does not charge for surface drainage separately. Instead, the surface drainage charge is included within the wastewater volumetric charge.

How to reduce surface drainage charges

Surface drainage charges are calculated based on the physical aspects of your property or business water connection, making them difficult to reduce.

However, the open water market provides an opportunity to save on surface drainage charges by choosing a cheaper supplier.

At AquaSwitch, we provide a no-obligation business water comparison service. Find out how much your business could save on surface drainage charges by switching business water suppliers.

Can I challenge my surface drainage charge?

Absolutely. The surface drainage charge is calculated based on the local water company’s data about your commercial property, which can sometimes be inaccurate.

Here are two typical examples where a surface drainage charge can be challenged:

Where the surface area being used on your water bill does not accurately reflect the boundary of your property.
Where the rainwater gets drained directly into a watercourse rather than the local drainage system.

If you believe you are overcharged for surface drainage, we recommend a business water audit or a water bill validation review.

Where overcharging can be demonstrated to your business water supplier, you may obtain a rebate for past water bills.

Can I get a surface drainage rebate?

If the rainwater falling on your business premises does not flow into the sewerage system, you can apply for a surface drainage rebate. The surface drainage rebate is a reduction in the annual surface drainage fee and a recalculation of past fees.

The surface drainage rebate application is made to your local water supplier and must include evidence that rainwater landing on your property does not enter the sewerage system.

The local water company must assess your application and, if successful, will:

Reduce or eliminate your surface drainage charges.
Give you a rebate for past surface drainage charges.

The ease of application and the speed of processing vary significantly between suppliers. A rebate for past surface drainage charges can be made up to the statute of limitations:

Scotland: 5 years
England and Wales: 6 years