Flood Alert Issued for River Thame, Horsenden Stream, and Chalgrove Brook in Oxfordshire and Surrounding Counties

Alert Details

The Environment Agency has issued a Flood Alert (Severity Level 3) for the River Thame, Horsenden Stream, and Chalgrove Brook. This alert was officially raised at 8:21 AM on March 7, 2026, following reports of high river levels that may lead to flooding in the region.

Affected Areas

The geographic scope of this alert includes regions within Buckinghamshire, Hertfordshire, and Oxfordshire. Specifically, officials have identified high levels on the Chalgrove Brook through Chalgrove. While levels along the River Thame are currently below the flood risk threshold, flooding of low-lying land and roads remains a possibility throughout the Chalgrove area.

What You Should Do

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

• Avoid using low-lying footpaths and roads near rivers, as these areas may be flooded.
• Monitor current river conditions by visiting River Levels Online for real-time updates.
• Remain vigilant as the situation develops, even if local conditions appear dry.

Expected Conditions

River levels are currently high on the Chalgrove Brook. Although the forecast predicts a predominantly dry day today and tomorrow, river levels are expected to fall very slowly over the coming days. Flooding is primarily expected to impact low-lying land and transport routes rather than residential properties at this stage.

Timeline

The alert is effective as of March 7, 2026. The Environment Agency is actively monitoring rainfall and river levels and expects the current conditions to persist with a slow decline in water levels. An update to this message is scheduled to be provided by 12:00 PM on March 8, 2026, or sooner if the situation changes significantly.