Flood Alert Issued for River Thame, Horsenden Stream, and Chalgrove Brook

Alert Details

The Environment Agency has issued a Flood Alert (Severity Level 3) for the River Thame, Horsenden Stream, and Chalgrove Brook. High river levels have been detected, which may lead to flooding in the region.

Affected Areas

The alert specifically affects geographic regions within Buckinghamshire, Hertfordshire, and Oxfordshire. Flooding of low-lying land and roads is expected to continue today, February 27, 2026, particularly in the area between Stadhampton and Dorchester.

What You Should Do

Residents and travelers in the affected areas are advised to take the following actions:

• Avoid Hazards: Stay away from low-lying footpaths and roads near rivers, as these may be flooded.
• Monitor Conditions: Visit River Levels Online for real-time updates on current water levels.
• Stay Alert: Be aware that river levels are expected to remain high and sensitive to additional rainfall over the coming days.

Expected Conditions

River levels are currently high on parts of the River Thame. The forecast indicates rain overnight on February 27, which could be heavy at times, followed by further rainfall over the weekend. These conditions are expected to keep river levels elevated.

Timeline

The alert was officially raised at 10:04 AM on February 27, 2026. The Environment Agency is monitoring rainfall and river levels and expects to provide an update by 12:00 PM on February 28, 2026, or sooner if the situation changes.