Sewer flooding causes
What causes sewer flooding? Identifying the issue makes it easier to know who's responsible for fixing it.
The three main causes of sewer flooding are:
Watch our video to see why sewer flooding happens.
Blockages in drains and sewers
Blocked pipes are expensive to fix and can cause a lot of damage, so it's important you know how to avoid this.
The only items you should flush down the toilet are the three Ps: pee, poo and (toilet) paper. Nappies, sanitary towels, tampons and wet wipes should always go in the bin.
Cooking oils and leftover food should never be poured down the sink. Scrape all leftovers into the bin before washing up and pour leftover oil into a container.
These blockages, or fatbergs, get bigger as more items get stuck in them. Eventually they'll block the pipe completely. The sewage can no longer drain away, so will flood back up into your home, gardens and roads.
Learn more about how to prevent sewer blockages at home.
Heavy or continued rainfall
When it rains heavily, or for a long time, the extra water can overwhelm our sewers. The sewer fills, backs-up pipes and drains and can flood properties, roads and streets with sewage. Some of our sewers weren't originally designed to carry rainwater. With climate change causing more intense rainfall, this type of flooding is becoming a bigger issue.
A lot of our green areas are being paved over and built on. This means we have a lot less natural drainage, as rain can't absorb into the soil. The surface water ends up in our sewers instead. If you're building an extension or new driveway, think about rainwater drainage.
Damage and system failure
It's our responsibility to maintain and repair the public sewer system. Burst pipes, sewer collapse or pumping station failure can all cause sewer flooding. If you see a blockage or flooding when you're out and about, you can report a problem to us here.
We’re working round the clock to respond to sewer flooding incidents. We're also investing in our network, increasing sewer capacity and reducing the need for storm overflows.