A Flood Alert was issued for Groundwater flooding in the Alton area in Hampshire on 21st April 2026. Affected watercourses included the Groundwater.
During this event, FloodRadar monitoring gauges recorded notable rises. The Petersfield Stream at Winchester Road rose 0.05m, peaking at 64.78m, while the River Wey at Alton High Street climbed 0.05m.
Environment Agency advice issued
Groundwater levels are high but are declining at our Farringdon borehole near Alton. Flooding of low-lying land and roads continues to be possible. We expect levels to continue to fall over the next few weeks in response to more settled weather. We are closely monitoring rainfall and groundwater levels. Residents are advised to ensure property resilience measures are prepared and check that pumps are working where they have been installed. Take particular care when driving through flood water both for your own safety and to prevent flooding to others. This message will be updated by 12:00pm on
Monitoring gauges during this event
| Station | River | Rise | Peak |
|---|---|---|---|
| Winchester Road | Petersfield Stream | +0.05m | 64.78m |
| Alton High Street | River Wey | +0.05m | 0.15m |