Flood Alert Issued for Upper Arun in Surrey and West Sussex

Alert Details

The Environment Agency has issued a flood alert for the Upper Arun area within the Solent and South Downs region. This alert was officially raised on the afternoon of Wednesday, February 18, 2026, in response to a weather system bringing rain to the region through Thursday.

Affected Areas

The alert covers geographic regions within Surrey and West Sussex along the River Arun. Specific locations identified as being at risk of minor flooding include:

• Fields and rural roads in the Upper Arun area.
• Gardens of Tanbridge Park and Blackbridge Court.
• Arunside School fields.
• Gardens of mill properties near Broadbridge Heath.
• Gardens near Pallingham Lock (expected from 10:00 on Thursday).

What You Should Do

Residents in Wanford are advised to consider activating any flood protection products they may have. The Environment Agency is currently operating an automatic sluice at Provender Mill to help mitigate flood risk. Residents should monitor local conditions closely, as isolated property flooding remains a possibility if rainfall totals exceed current forecasts.

Expected Conditions

Rain is forecast from Wednesday afternoon through Thursday. Minor flooding is expected to begin affecting fields, roads, and gardens starting from 23:00 on February 18. While only isolated showers are expected from Thursday afternoon through the weekend, the Environment Agency notes that unsettled weather could continue throughout February, maintaining a period of flood risk.

Timeline

The alert is effective immediately. River levels in Horsham are expected to begin falling by 10:00 on Thursday, February 19. At Pallingham Lock, levels are anticipated to start receding by 22:00 on Thursday evening. River levels will continue to fall slowly through Friday and the weekend. This alert is scheduled for an update by 20:00 on February 19.