Environment Agency062WAF50AshHertsHerts and North London
River Ash in Hertfordshire: flood history since 2011
The Environment Agency has issued 27 flood alerts for River Ash in Hertfordshire since 18 Jan 2011, most often in January; the busiest year was 2024 (6).
Flood alerts only
The flood area
- Flood area
- River Ash in Hertfordshire
- Code
- 062WAF50AshHerts
- Environment Agency area
- Herts and North London
- County
- Hertfordshire
- River or sea
- Ash
- First in the history
- 18 Jan 2011
- Latest in the history file
- 8 Dec 2024
- Current status
- check-for-flooding.service.gov.uk (the Environment Agency's live page)
Flood alert, flood warning, severe flood warning: what each means
Source: Environment Agency, Historic Flood Warnings (England); Environment Agency flood-monitoring API. Contains public sector information licensed under the Open Government Licence v3.0.
How many alerts and warnings a year?
Flood alerts, flood warnings and severe flood warnings (updates not counted), by year. 2026 runs to the end of June.
The numbers
| Year | Alerts | Warnings | Severe |
|---|---|---|---|
| 2024 | 6 | 0 | 0 |
| 2023 | 1 | 0 | 0 |
| 2021 | 3 | 0 | 0 |
| 2020 | 2 | 0 | 0 |
| 2019 | 1 | 0 | 0 |
| 2017 | 1 | 0 | 0 |
| 2016 | 3 | 0 | 0 |
| 2014 | 5 | 0 | 0 |
| 2013 | 2 | 0 | 0 |
| 2012 | 2 | 0 | 0 |
| 2011 | 1 | 0 | 0 |
Source: Environment Agency, Historic Flood Warnings (England); Environment Agency flood-monitoring API. Contains public sector information licensed under the Open Government Licence v3.0.
When in the year?
All alerts and warnings since 2011 by month.
Source: Environment Agency, Historic Flood Warnings (England); Environment Agency flood-monitoring API. Contains public sector information licensed under the Open Government Licence v3.0.
Before July 2026: the latest in the history file
| Date | Level |
|---|---|
| 8 Dec 2024 | Flood alert |
| 22 Feb 2024 | Flood alert |
| 18 Feb 2024 | Flood alert |
| 8 Feb 2024 | Flood alert |
| 4 Jan 2024 | Flood alert |
| 2 Jan 2024 | Flood alert |
| 31 Mar 2023 | Flood alert |
| 26 Dec 2021 | Flood alert |
| 28 Jan 2021 | Flood alert |
| 14 Jan 2021 | Flood alert |
| 16 Feb 2020 | Flood alert |
| 16 Jan 2020 | Flood alert |
Source: Environment Agency, Historic Flood Warnings (England); Environment Agency flood-monitoring API. Contains public sector information licensed under the Open Government Licence v3.0.