A Flood Alert was issued for Groundwater flooding in Denmead in Hampshire on 18th March 2026. Affected watercourses included the Groundwater.
During this event, FloodRadar monitoring gauges recorded notable rises. The River Wallington at North Fareham weir rose 0.05m, peaking at 0.38m.
Environment Agency advice issued
Groundwater levels have been falling steadily. We do not expect further flooding and the flood alert has been removed. Rivers and streams remain full due to high groundwater levels and will react rapidly to further rainfall. Sewerage system impacts may continue during March. We will continue to monitor the situation and will issue further alerts or warnings if necessary. Septic tanks may need emptying as soakaways may not work for some time. You are advised to take the opportunity to check any pumps are in good working order and that stocks of sandbags are replenished.
Monitoring gauges during this event
| Station | River | Rise | Peak |
|---|---|---|---|
| North Fareham weir | River Wallington | +0.05m | 0.38m |