Buried in most business water bills is a charge for surface water drainage — and it is one of the most commonly overpaid items on the whole bill. If the rainwater from your site doesn't actually drain into the public sewer, you may not owe it, and you could be due a reduction going forward and sometimes a backdated refund. Here is how to check.
What the charge is for
Surface water drainage (and the related highway drainage charge) covers rainwater that falls on your site — roofs, car parks, yards — and drains into the public sewer system. Because it costs the network to carry that water away, you are charged for it, usually as a fixed part of your water bill.
Why you might not owe it
The catch is that the charge often assumes your site drains to the public sewer, when in reality it may not. You may have a case for a reduction if:
- Your site drains to a soakaway rather than the public sewer.
- Rainwater drains directly to a river, stream or water course.
- Part of your site is unbuilt or drains elsewhere, so you are charged for more area than applies.
Because the charge is often estimated, plenty of businesses pay for drainage they simply don't use.
How to check and reclaim
- Find the charge on your bill — look for surface water and highway drainage lines.
- Check where your site actually drains — a site plan or a look at your drainage helps establish this.
- Raise it with your water retailer with evidence. If your site doesn't drain to the public sewer, you can ask for the charge to be removed or reduced.
- Ask about backdating — where a charge was applied in error, a reduction can sometimes be backdated.
This is one of several errors we cover in our guide on business water bill errors.
How Win Energy helps
Checking drainage charges is fiddly, so we do it for you. We review your business water bill line by line, identify charges that may not apply, and help make the case to your retailer — including for a backdated reduction where one is due. We are honest about it, too: if the charge is correct, we will say so.
Think you might be paying for drainage you don't use? Send us a recent water bill and we will check it — free, with no obligation. Call 0845 862 1947 or get in touch.
Surface water drainage is a small line that can add up over years. It takes a few minutes to check where your site drains — and if the answer isn't the public sewer, that check could be worth a meaningful, sometimes backdated, reduction.