A Flood Alert was issued for Thorney Island to West Itchenor in West Sussex on 25th October 2026. Affected watercourses included the Chichester Harbour.
During this event, FloodRadar monitoring gauges recorded notable rises. The Tide at Medmerry rose 1.49m, peaking at 2.79m, while the Hermitage Stream at Havant climbed 0.41m.
Environment Agency advice issued
High tides on Sunday may lead to flooding. Flooding is possible for 1 hour either side of Sunday evening's tide at 22:30 on 25/10/2026. The weather increases tide table values by 0.48 m. Total forecast tide is 5.24 metres Chart Datum (2.50 mAOD) at Chichester Harbour. The tide will flood Shore Road. At Bosham High Street, water will be near to or flood front door steps. Land of shore side properties around the Harbour could also be affected. Monday morning’s tide at 11:00 on 26/10/2026 is forecast to be 15cm higher. A Flood Warning will be issued for Monday morning’s tide and isolated proper
Monitoring gauges during this event
| Station | River | Rise | Peak |
|---|---|---|---|
| Medmerry | Tide | +1.49m | 2.79m |
| Havant | Hermitage Stream | +0.41m | 5.49m |
| Crosslands Drive | River Lavant | +0.36m | 0.49m |
| Emsworth | West Brook | +0.34m | 2.09m |
| Chichester Tozer Way | River Lavant | +0.24m | 12.86m |
| West Street | River Lavant | +0.18m | 7.22m |
| Westbourne | River Ems | +0.06m | 0.13m |