Surface water drainage charges do not relate to the drinking water used inside a building. They relate to the management of rainwater draining from the property.
What Is Surface Water?
Surface water is rainwater that falls on roofs, yards, car parks and other areas of a property.
Where this water enters the public sewer network, a charge may be applied for its removal and treatment. This can form a significant part of the wastewater costs associated with some commercial and organisational premises.
It is different from:
Water supplied through the incoming water main
Foul sewage from toilets, kitchens and washrooms
Trade effluent from industrial or commercial processes
Highway drainage associated with public roads
Understanding these distinctions helps an organisation identify what each element of its wastewater charges is intended to cover.
How Can Surface Water Drainage Be Charged?
Charging arrangements vary according to the relevant wholesaler and charging structure.
One possible approach is site area charging. CCW’s explanation of site area based charging states that the approach is used to determine what a business should pay for surface water drainage and reflects the principle that a larger site is likely to contribute more rainwater to the drainage system. [ccw.org.uk]
Depending upon the applicable arrangements, the charge may be influenced by:
The assessed area of the site
The charging band into which the premises falls
Property or valuation information
The nature of the drainage connection
The wholesaler’s published charging scheme
The business water retailer may present the charge, but the underlying wholesale charging arrangements are also important.
Why Might the Site Area Need Attention?
Property information can change over time.
A site may have been:
Extended
Partially demolished
Divided between occupiers
Combined with neighbouring land
Reconfigured
Sold in part
Redeveloped
Provided with new or altered drainage arrangements
Where a charge depends upon site characteristics, it is reasonable to ask whether the recorded information continues to reflect the property.
A large charge is not evidence that the assessed area is wrong. Equally, a long standing charge should not be treated as correct solely because it has appeared for many years.
What If Rainwater Does Not Enter the Public Sewer?
Some premises may have drainage arrangements that direct some or all rainwater elsewhere, subject to the physical layout, legal permissions and environmental requirements affecting the site.
Possible arrangements may include discharge to:
A soakaway
A watercourse
Sustainable drainage infrastructure (SuDS)
Private drainage systems
Another permitted destination
The physical existence of a drain or pipe does not, by itself, establish its destination. Reliable plans, surveys, asset information or investigation may be needed.
Any environmental, planning or legal requirements should be considered by appropriately qualified professionals.
What Information May Be Useful?
A proportionate review may consider:
Current and historic bills
The description and value of the drainage charge
The premises address
Property boundaries
Site plans
Roof and hardstanding areas
Drainage plans
Evidence of redevelopment
Information about outfalls, soakaways or other drainage assets
Correspondence with the retailer, wholesaler, landlord or managing agent
For shared sites, it may also be necessary to understand whether the charge relates to one occupier, communal areas or a wider estate.
What About Highway Drainage?
Highway drainage is associated with rainwater draining from public roads and highways into the sewer network.
It is distinct from surface water draining from the customer’s own property. The two charges may be presented separately or as part of the applicable wastewater charging structure.
A change to the drainage arrangements within a customer’s site may therefore affect one charging element without necessarily removing other wastewater charges.
A drainage charge should be understood by reference to the property, the applicable charging method and the available evidence about where rainwater goes.
How WTR Utilities Can Help
WTR Utilities can review the available bills, charging information, plans and site evidence to help establish how a surface water drainage charge has been applied.
Where information appears incomplete or inconsistent, we can identify the questions that may need to be raised and the evidence likely to be relevant.
Important information: This article provides general information about non-household water and wastewater arrangements. Individual accounts, properties and charging arrangements vary. The content should not be treated as confirmation that any particular charge is correct or incorrect, or as legal advice on a lease or property agreement.