Extreme weather was to blame for the flooding of 300 properties in Blackpool during 48 hours of heavy rainfall in November 2017, a council investigation has concluded.
A statutory section 19 report by the council into the incident has found authorities including the council and water company United Utilities fulfilled their duties in trying to help residents on the night.
This included the use of Anchorsholme pumping station which the report confirms could not pump water into the sea when the Fylde coast water storage system was filling up in the days before the November 22 storm.
Its pumps could only be triggered when the system reached a predetermined capacity.
The report states: "The pumping station cannot operate if the water level in the tunnel does not get above this start height and so the pumping station cannot be operated any earlier in terms of reducing levels in the tunnel, for example to manage and reduce levels prior to forecasted rainfall."
Although one of the five pumps at Anchorsholme had been subject to "intermittent tripping" throughout the evening, the report says United Utilities "confirmed that without this pump failure the severity of the flooding would have remained the same."
The rainfall was described as a one-in-64-year level storm which overwhelmed the drainage system including rivers and streams.
Now a £110,000 study into what can be done to help prevent a repeat of the situation is to be implemented funded jointly by United Utilities and the Environment Agency.
The report, which has just been published, says: "Given the rapid onset of this incident and the lack of Met office warning there was little opportunity for preparation.
"However the investigations by the Flood Risk Manager and close working with other risk management authorities (RMAs) show that the undertaking of duties by Blackpool Council and United Utilities were deployed.
"It is concluded that the flooding was caused by an exceptionally severe weather event as the entire integrated drainage system including highway drainage system, watercourses, sewers, main-river and the water table was completely saturated."
A United Utilities spokesperson said: “We are pleased the report confirms the pumping station at Anchorsholme was working and operating as designed.
"It also shows storm flooding is a complex issue with no simple answer. Not one organisation can solve flooding in isolation and the importance of collective partnership work is paramount.
“We remain absolutely committed to working with the Lead Local Flood Authority (Blackpool Council) and other agencies to ensure issues are investigated thoroughly and measures are put in place to minimise the risk of flooding now and into the future.”
The largest area of recorded flooding was East Anchorsholme in the area bounded by Warren Drive, Sevenoaks Drive, Wood Green Drive, North Drive and Snowhills Crescent.
The latter was impassable due to water reaching around half a metre in depth, while electricity supplies were also cut to some areas.
However water did recede during the morning of November 23.
Anchorsholme ward councillor Tony Williams said while the report explained the events on the night it still left some questions.
He said: "I believe a fully working pump system would have eased the situation as United Utilities has admitted one of the pumps was tripping throughout the night and not fully working.
"Surely if this had been fully functional it will have made a difference, otherwise why continue to try and keep it working?
"I do think the report does provide a more accurate record of the events that occurred at the time but it doesn't admit partial responsibility or blame."
Coun Williams said he would monitor the research to be carried out to help prevent future flooding but he remained concerned some affected residents had still not received any compensation.
Councillors had previously accused the company of not pumping excess floodwater into the sea for fear of damaging the quality of the bathing water.
The section 19 report has suggested nine recommendations -
Research to better understand the causes of flooding and mitigation measures in all areas that were flooded.
Investigate the potential for flood resilience in certain properties.
Work with Highways England to ensure culverts are not impeding the flow of water.
Investigation and clearance of watercourses and better management of surface water in the catchment areas by working with the Environment Agency.
Discussions with United Utilities and Network Rail to find a solution to repeated disruption at Devonshire Road Bridge during heavy rainfall.
Consider more modern methods of practical help for residents and a review of the assistance provided using sandbags.
Information to be provided on the council’s website to assist and update residents.
Set up a flood resilience forum in Blackpool.
Partnership work with Wyre Council and United Utilities to provide improvement to water storage and flow in the Hillyaide Brook and Royles Brook Rivers.
According to the report, measures taken on the night included United Utilities diverting flows from Skipool pumping station, serving Poulton and surrounding areas, away from the Anchorsholme catchment.
The diversion of storm water to the River Wyre is said to have "undoubtedly mitigated flooding to areas of the Anchorsholme catchment."
In Bispham, Blackpool Council officers attended but could not alleviate the flooding as, similarly to Anchorsholme, the ground was saturated and sewage systems full to capacity.
Highways teams reported evidence of water surging into properties, over the carriageway and into gardens in some streets.
The report says: "Water had entered properties largely under the floor. The road was flooded in parts up to one metre deep. In addition these properties had suffered electrical disruption."
Sandbags from the council "proved ineffective as water levels had risen quickly and sewer surcharge had entered the property under the floor".