Following a flood event on 23 September 2024, a recent investigation has found that some properties near the River Wandle are at high risk of future flooding. The flooded properties are within the floodplain, and recent modelling by the Environment Agency (EA) confirms that the properties impacted by this event are at high risk of flooding.
The findings were presented at the Hackbridge, St Helier and The Wrythe Local Committee meeting on Thursday 17 July 2025, where Councillor Patrick Ogbonna, Chair of the committee, and other councillors reviewed the report.
The Flood Investigation Findings report detailed that nine properties experienced internal flooding during the September 2024 event, with roadway flooding reported at Goat Road. The flooding was first reported at 3am BST.
The report indicated that a Flood Guidance Statement had been issued by the Flood Forecasting Centre at 10:30 AM on 22nd September 2024, which indicated a low risk of flooding from rivers. While a flood alert threshold was crossed, no alert was issued because it was after 9pm. According to the Flood Investigation Findings, after the flood, the EA reviewed recorded flood levels in conjunction with the latest River Wandle modelling finalised in April and lowered the flood warning service thresholds.
A flood warning was also not issued because property flooding was not expected.
The report also addressed the recent modifications to the Goat Bridge Weir, stating that they are unlikely to have worsened the flooding. The report stated:
The works, completed before the flood event, involved lowering the weir height to enhance fish passage and also provided additional flood storage capacity.
The report outlined the responsibilities of both Sutton Council and the Environment Agency in managing flood risk, including investigating flooding incidents, developing and maintaining local flood risk management strategies, and maintaining an asset register of structures that affect flood risk.
The report concluded that the River Wandle is a flashy river due to its catchment size, geology, and urbanisation, making it susceptible to intense rainfall. It suggested that increasing permeable surfaces and sustainable drainage could counteract the risk of flooding.
The Public Reports Pack included a reminder that the council has a duty to investigate flooding incidents and to develop, implement, and maintain local flood risk management strategies.
The council encourages residents to visit their flooding advice page for information on warnings, alerts, and how to create a flood plan. Residents can also report flooding to the Environment Agency Floodline on 0800 807060.
