A Flood Alert was issued for Upper River Colne and Radlett Brook in Hertfordshire on 25th October 2026. Affected watercourses included the River Colne.
During this event, FloodRadar monitoring gauges recorded notable rises. The River Colne at Thorney Mill Road, West Drayton (Temporary) rose 0.33m, peaking at 0.45m, while the River Colne at Farlows Bridge climbed 0.25m.
Environment Agency advice issued
There is no longer a threat of flooding, though standing water and debris may still remain. Weather conditions are expected to improve. Further light rainfall is expected on Monday 26 October but no flooding is expected. We will continue to monitor the situation and will issue further alerts or warnings if necessary. Continue to take care on waterside roads and footpaths and don't put yourself in unnecessary danger.
Monitoring gauges during this event
| Station | River | Rise | Peak |
|---|---|---|---|
| Thorney Mill Road, West Drayton (Temporary) | River Colne | +0.33m | 0.45m |
| Farlows Bridge | River Colne | +0.25m | 0.69m |
| Iver, Clisbys Bridge | River Colne | +0.20m | 0.56m |
| Denham Colne | River Colne | +0.13m | 0.25m |
| Willowbank | River Colne | +0.11m | 0.95m |
| Colney Street | River Ver | +0.09m | 0.26m |
| Moor Lane | River Colne | +0.07m | 7.53m |