Environment Agency27 Aug 2026
Flood alert: Upper River Colne and Radlett Brook
The Environment Agency raised a flood alert for Upper River Colne and Radlett Brook (Hertfordshire). The Environment Agency has issued 116 flood alerts, 0 flood warnings and 0 severe flood warnings for this area since 10 Feb 2009 (the area's history).
Flood alert
The notice
- Issued by
- Environment Agency
- Area
- Upper River Colne and Radlett Brook
- Level
- Flood alert
- Issued
- 09:39, 27 Aug 2026
- County
- Hertfordshire
- River or sea
- River Colne
- Flood area code
- 062WAF28UpColne
- Official source
- Environment Agency: the notice at its source
Source: Environment Agency: the notice at its source. AreaZine rebuilds this page from the agency's record; the agency's page is the one to act on. This uses Environment Agency flood and river level data from the real-time data API (Beta). Contains public sector information licensed under the Open Government Licence v3.0.
The notice as issued
Rising river levels may lead to flooding today Thursday 27 August 2026 due to forecast heavy rain and storms. Locations most affected will be Waterside, Lowbell Lane, London Colney, Warrengate Road. Flooding from surface water, where water gathers and flows off road surfaces, could also occur. We expect river levels in areas that receive the heaviest rain to respond by rising quickly. Further heavy rain and thunderstorms are forecast during the day on Thursday 27 August and into Friday 28 August. We are closely monitoring the situation and we are prepared to issue flood warnings if required. Take care and avoid walking, cycling or driving through flood water and avoid using low lying footpaths and any bridges near watercourses. This message will be updated by 05:00 PM on 27 August 2026 or as the situation changes.
Source: Environment Agency: the notice at its source. The text is the agency's, unedited. This uses Environment Agency flood and river level data from the real-time data API (Beta). Contains public sector information licensed under the Open Government Licence v3.0.