"Exceptional" Rain To Blame For Canvey Flooding

8 October 2014, 09:04

A report into the heavy flooding on Canvey Island this summer has found "exceptional" rainfall was the main cause.

Several communities and scores of homes were affected when the rain hit on July 20.

In the report, Essex County Council says a million cubic metres of water - enough to almost fill Wembley Stadium - fell in just over four hours and the island's drainage system was overwhelmed.

Previously it had been known that a number of the Environment Agency's pumps had failed for around 12 minutes, but this report confirms nine EA pumps failed during the course of the day and three for as long as two hours.

The report says about the pumps: "Between 1550 and 1610 hrs the 3 pumps at Croppenburg tripped out before being re-started at 1820 hrs. Between 1605 hrs and 1903 hrs, 3 of the 4 pumps at Scarhouse tripped out. All of the 3 pumps at May Avenue tripped out for 23 minutes from 1718 and again from 1851 hrs for 32 minutes."

However the report says neither this or the council's maintenance of the drainag system contributed to the flooding: "The magnitude of rainfall experienced was unprecedented and well beyond the national standards for design capacity of sewers and surface water drainage systems, causing the system to be overwhelmed in multiple locations.

"The evidence provided suggests that this occurred in the early stages of the drainage system, and the operation of the pumps did not contribute to the flooding.

"The pumps form the final stage of a long and incredibly complex system, and rainfall on the island may flow a substantial distance before reaching them."

"Additionally, whilst there have been reports by residents that blockages in highway drains may have caused localised flooding, there is no evidence to suggest that any widespread failure of the drainage system occurred due to insufficient maintenance or poor condition of these or any other publicly or privately owned infrastructure.

"Even with a completely clear drainage system, and substantial and widespread improvements to the capacity it is likely that severe flooding would have occurred during this event and will do in similar events in the future.

The report does identify failings with communication to the public though, saying that "during the event misleading and in some cases incorrect messages were given to the public, and that avenues of communication between Category 1 responders were insufficient to ensure that accurate, effective and coordinated communication took place with local residents."

The report has also set out the following 13 recommendations:

1. Commit to a multi-agency “task and finish” group to be led by the LLFA, which will take evidence from all stakeholders and bring forward a plan of action for managing flood risk based on evidence including the results of the IUD study.
2.  Consideration of the feasibility of increasing the design capacity of surface water drainage systems on Canvey Island at problem points and critical drainage infrastructure as identified by the IUD study and other relevant evidence.
3. Review and improve their maintenance/inspection regimes of drainage infrastructure throughout Canvey Island.
4. Commit to greater resident involvement in any future study or works to improve drainage systems.
5. Investigate options to provide property level protection to residents where larger flood alleviation schemes are not possible.
6. Confirm ownership and role of Canvey Lake, take actions to increase storage capacity (e.g. dredging and lower water levels) and investigate options to increase outflow capacity.
7. Map and confirm ownership and condition for all drainage assets on the island.
8. Raise public awareness of flood resilience measures to reduce the impact of internal flooding on property and of landowner responsibilities for maintaining private culverts and watercourses.
9. Use wider dissemination of information from campaigns such as “Six Steps to Flood Resilience” and “Know Your Flood Risk” to provide information to residents on what to do before, during and after flooding.
10. Emergency Planning – Consider communications before flood events, coordination of emergency response and deployment of available resources.
11.  Improve communication and joint working between responders during events.
12. Support Emergency Planning by providing all information on flood risk available prior to an event.
13. Collectively bid for funding for multi-million pounds of external funding which will be required to fund capital projects to improve the drainage infrastructure, and provide for property level protection on Canvey Island.

County Councillor Roger Hirst, Cabinet Member for Libraries, Communities and Planning, said: "This comprehensive Flood Investigation Report shows how agencies need to work together in a 'task and finish' group to improve an aging and complex system. I am looking forward to putting its recommendations into action with our partners to reduce the risk of flooding on Canvey Island."

Castle Point MP Rebecca Harris said: "Hundreds of lives were devastated in Castle Point as a result of the flooding and I will do all I can to fight for this request for funding from the Government to go forward. It is clear that parts of Castle Point have suffered from decades of local underinvestment in the drainage infrastructure.

"I welcome the extra money that Essex County Council and Anglian Water are now putting into the drainage network. But to give this bid for extra funds from the Government the greatest chance of success, the various agencies will need to continue to work together to come up with solid costings and a plan of how they will use any additional funds and explain why they can't tackle this problem themselves without Government support."

Dr Charles Beardall, Area Manager, Environment Agency said:  "The report clearly outlines the events of 20 July and states the need for us all to continue to work closely together to identify and deliver the improvements that are necessary to reduce the risk of flooding on Canvey Island. We remain committed to this approach."

Cllr Coin Riley, Leader of Castle Point Borough Council, said: "I welcome this important report which provides an excellent start to a process to develop, manage and reduce flood risk on Canvey Island and provide lasting reassurance for residents."

Paul Gibbs, Director of Water Recycling for Anglian Water, said: "We want to assure residents on Canvey and across our wider region that we are doing all that we can to make sure the parts of the drainage network we are responsible for are well maintained and fit for purpose. It is vital that we continue to work together with our partners who manage other parts of the network and focus on reducing the risks of flooding for all of our customers."

You can see the full report here: www.essex.gov.uk/flooding