The city council is looking at extreme floods that happens once every 200 years.
Flooding wrecked havoc in sections of Wirral last week, prompting an investigation.
Merseyside was battered by heavy rain on Thursday afternoon, with cars buried in water in Birkenhead and numerous Wirral schools having to close.
After damage to the road surface, parts of Borough Road in Birkenhead, one of the “most impacted” areas, were closed to traffic on Friday.
After being teased by Home Bargains employees, a disabled woman is in tears.
A small’sinkhole’ has also emerged on Abbey Street in Birkenhead.
However, the floods affected other sections of Wirral as well.
According to experienced Labour councillor Jerry Williams, this included roads in Bebington that had “never flooded” before, with the town’s Acres Road being particularly heavily impacted.
On Thursday, 68 millimetres of rain fell in Birkenhead in three hours, more than half of Wirral’s average September rainfall (120 mm), with a total of 93 millimetres falling in Wirral throughout the day.
This was a “one in 200-year” storm, according to Wirral Council, and it exceeded the standards of its drainage systems, which can only handle 1 in 30-year rainfall.
This clogged sewers across Wirral, forcing numerous council teams to respond with an emergency response, with operational workers dispatched to the worst-affected locations to collect debris from surface water drains and unblock blocked drains.
Given the severity of Thursday’s floods, the council has scheduled a “debrief” with United Utilities to see if any operational difficulties contributed to the flooding and what United Utilities’ short-term reaction strategy is.
Welsh Water, which serves Heswall and Gayton, will have a similar gathering.
Wirral Council, as Lead Local Flood Authority, will conduct the complete investigation as required by Section 19 of the Flood and Water Management Act 2010.
On the council’s website, the final report will be available.