Policy paper

Whittlesey Washes South Barrier Bank flood defence scheme

Updated 15 October 2014

Applies to England

The Whittlesey Washes flood storage reservoir lies to the south of the River Nene, east of Peterborough. It plays an important part in helping to reduce the risk of flooding during combined high tides and river flows.

How it works

Flood water is stored on the Washes when high river levels cannot be released downstream due to high tides. This is when the river is ‘tide-locked’. As the tide recedes, water is released from the reservoir and back into the River Nene from the eastern end of the Washes. The equivalent of 14,000 olympic-sized pools of flood water can be temporarily stored on the Washes.

The reservoir is approximately 20 kilometres long and up to 1.4 kilometres wide in places. It covers an area of approximately 1,450 hectares, protecting hundreds of properties, as well as roads, railways and more than 8,000 hectares of farmland in the Fenland area to the south east of Peterborough.

The Whittlesey Washes is designated as a:

• Site of Special Scientific Interest
• Special Area of Conservation
• Special Protection Area
• Ramsar site

What the Environment Agency is doing

The flood storage reservoir is made up of two banks, the Cradge Bank and the South Barrier Bank. When the reservoir operates, it stores more than 25,000 cubic metres of water above surrounding ground levels. Because of this, it is routinely inspected by an independent engineer as part of the Reservoirs Act 1975.

A recent engineer’s inspection found that a 16 kilometre stretch of the South Barrier Bank needed improving to maintain its structural integrity. The South Barrier Bank forms the 18 kilometre reservoir bank between Stanground and Ring’s End.

In 2013, the Environment Agency began a £26 million flood defence scheme to strengthen the banks. The work involves reshaping the slope of the bank and placing extra material at the base of it. In total, 330,000 cubic metres of material from local quarries will be used.

The scheme will take place over 3 years and has been split into phases. The first phase of works on a 5 kilometre stretch between Ring’s End at Guyhirn and Poplar House Farm began in July 2013. This phase is due to be completed in autumn 2014.

The second phase of works a 7 kilometre stretch of bank between Poplar House Farm and Bassenhally started in August 2014. This phase is expected to be completed in 2015. In spring 2015, work will begin on the 3 kilometre stretch between Stanground and Ball Bridge.

As the Washes are an internationally-important site, the majority of the work will take place in the summer and early autumn to avoid disturbing breeding and over-wintering bird populations.

Footpath and cycle route diversions

The Nene Way public footpath will be diverted to keep people safe while the works are carried out. The footpath diversion between Ring’s End and Poplar House Farm will remain in place until December 2014 when we are due to finish work at this location. The footpath has been diverted to the bottom of the bank on the northern side of the bank and is clearly marked out by fencing.

The Environment Agency will need to divert the Green Wheel cycle route between Stanground and Whittlesey when work starts in 2015. Details of the diversion will be displayed on notice-boards at each end of the working area.

The Environment Agency apologise for any inconvenience this may cause and will keep disruption to a minimum.

Working with partners

The Whittlesey Washes scheme is being carried out by the Environment Agency with support from partners, including:

• North Level District Internal Drainage Board
• Whittlesey Consortium of Internal Drainage Boards
• Middle Level Commissioners, Fenland District Council
• Peterborough City Council
• Cambridgeshire County Council
• Natural England
• RSPB