Flood Alert Issued for Upper River Colne in Hertfordshire
Areazine synthesizes this Environment Agency flood warning directly from Environment Agency's official public data feed. See our methodology for full source attribution and refresh cadence.
A flood alert has been issued for the Upper River Colne and Radlett Brook due to possible flooding from heavy rain and storms on 27 August 2026.
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- Record type
- Flood Alert
- Affected area
- Hertfordshire
- Issued
- August 26, 2026
- Issuing authority
- Environment Agency
Flood notices turn on location and timing. Treat the named area as this record's scope; do not assume nearby counties, parishes, or waterways were included.
Record status: publication date is recent, but current status is not stored on this page. Check the issuing agency's live warning service before acting because warnings can be updated, narrowed, or cancelled.
Alert Details
Type: Flood alert (severity level 3) Issued by: Environment Agency Effective time window: Raised 26 August 2026 at 21:38; flooding possible on 27 August 2026
Affected Areas
Upper River Colne and Radlett Brook in Hertfordshire. Low lying land, roads and riverside gardens are most at risk. Flooding from surface water could also occur.
What You Should Do
Take care and avoid walking, cycling or driving through flood water. Avoid using low lying footpaths and any bridges near watercourses.
Expected Conditions
High river levels overnight may lead to flooding due to forecast heavy rain and storms. River levels in areas receiving the heaviest rain are expected to rise quickly. Further heavy rain and thunderstorms are forecast during the day on Thursday 27 August and into Friday 28 August.
Timeline
Alert raised 26 August 2026 at 21:38. Flooding possible on 27 August 2026. Message will be updated by 10:00AM on 27 August 2026 or as the situation changes. The agency is monitoring and prepared to issue flood warnings if required.
Original source: Environment Agency Official Notice ↗
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Nationwide notices with similar length or severity timing 8
Two Areazine-derived peer sets for this Environment Agency flood warning: nearest notices by body length and by same severity near the same agency date. Peers come from other categories so they are not the same-feed Related list above.
Similar body length
Nearest notices by article body length (1,077 characters here).
Similar severity timing
Same severity (medium) notices issued closest in time to August 26, 2026.
Frequently Asked Questions
Common questions about this Environment Agency flood warning.