A study into the impacts of major flood defence schemes for Warrington is required before any work can be carried out.
The decision was made by Warrington Borough Council's planning department following an application from the Environment Agency seeking a review opinion.
This asks local governments whether an Environmental Impact Assessment is required to enable project decision makers to consider environmental impacts as early as possible and avoid, mitigate or offset them.
Council confirmed that the proposed Sankey Brook Flood Risk Management Plan requires such an assessment.
The Environment Agency said: “We are proposing to carry out works to manage the flood risk within Warrington from Sankey Brook, Durham Brook and Longford Brook.”
The proposed scheme covers Sankey Brook from north of the M62 to its confluence with the River Mersey south of Warrington.
It also includes the areas around Longford and Durham Brooks and areas west of the Sankey Canal.
“The proposed scheme includes new linear flood defences, including both flood barriers and embankments, as well as localised ground raising,” the EA continued.
“Warrington has experienced flooding in the past and the risk of flooding is primarily from rivers, however surface water and tidal flooding is also significant in some areas.
“The most recent and widespread event occurred in January 2021, when heavy rains from Storm Christoph caused Sankey Brook to burst its banks in multiple locations across the region.”
The proposed plans include linear defences along Sankey Brook, the Sankey Canal and Durham Brook, including 3.7km of wall, 2.4km of banks and 1,121m of ground raising.
Works will also include installing valve gates at Durham Brook in Longshaw Street, modifying the parapet of the existing bridge at Longshaw Street to act as a flood defence, installing two 32 metre temporary flood defences on Liverpool Road, upgrading Longford Barrage pumping station and reducing flooding at surface water hotspots such as Sankey Bridge and Orford.
In planning documents the Environment Agency said: “It is the Environment Agency's view that the proposed plans may pose risks of significant environmental impacts which cannot be successfully mitigated by sensitive design or other best practice measures.”
“This is due to the potential impact that the additional infrastructure will have on the landscape character of the area and could result in visual impacts.
“In considering the request for review opinions, the following points need to be emphasized:
“The proposed plans may require tree felling in many areas and may impact on protected species and habitats within the wildlife refuge.”
In making its decision, the council said: “In the opinion of the local planning authority, an environmental impact assessment is required for the development.”
“This is a major development for flood protection across much of Warrington, affecting designated areas, cultural heritage and nature conservation areas which are in flood zones.”