Surface water and groundwater
Surface water flooding occurs when heavy rain can't be absorbed by the ground or drains. Water flows over the surface and gathers in low areas. This is the biggest flood risk for Hillingdon residents.
Water is captured by gully pots at the side of most roads and flows into Thames Water sewers. Our highways teams clear over 36,000 gullies in Hillingdon each year, and they focus more often on priority areas.
After heavy rain, water on roads or open land is expected, despite preventive efforts. This can be due to blockages in other parts of the drainage system.
However, if water is still present after a few hours and you believe the issue is being caused by a blocked or damaged gully, you can report this to us using our online form, which you can also use to report a missing gully cover.
Please note: Gullies on private roads are the responsibility of the landowner, often shared between residents.
Report a blocked or damaged gully
You can also tell us about a problem with a roadside ditch.
Report a roadside improvement or corrections
Groundwater
Groundwater flooding occurs when the water table rises, causing water to surface and flood areas, typically after long periods of heavy rain.
Heavy rain can cause road flooding. If this happens, we will post updates and advice on our social media. Please reconsider if your journey is necessary.