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

Flood Warnings medium Environment Agency · · Buckinghamshire, Hertfordshire, and Oxfordshire

The Environment Agency has issued a flood alert for parts of Buckinghamshire, Hertfordshire, and Oxfordshire due to high river levels and incoming rainfall.

Alert Details

The Environment Agency has issued a Flood Alert (Severity Level 3) for the Thames area, specifically targeting the River Thame, Horsenden Stream, and Chalgrove Brook. This alert indicates that flooding is possible and residents should remain vigilant.

Affected Areas

The alert covers geographic regions within Buckinghamshire, Hertfordshire, and Oxfordshire. Specific areas of concern include low-lying land and roads in the Chalgrove area, as well as regions adjacent to the River Thame and Horsenden Stream.

What You Should Do

Residents in the affected areas are advised to avoid using low-lying footpaths and roads near rivers, as these may be flooded. The Environment Agency recommends monitoring local weather reports and visiting River Levels Online for real-time updates on water levels.

Expected Conditions

Currently, river levels are high on the Chalgrove Brook through Chalgrove, though levels along the River Thame remain below the flood risk threshold. A weather system is forecast to bring rain starting the afternoon of March 6, 2026, continuing overnight into the following morning. While flooding of low-lying land is possible today, dry conditions are expected to return by tomorrow afternoon, which should allow river levels to fall.

Timeline

The alert was officially raised at 10:23 AM on March 6, 2026. The forecast rain is expected to persist through the night of March 6 and into the morning of March 7, 2026. The Environment Agency expects to provide a formal update on the situation by 12:00 PM on March 7, 2026, or sooner if conditions change significantly.

Source: Environment Agency Official Notice