Imagine London plagued by devastating floods. Now, envision a solution. That’s the story of the River Lee Flood Relief Channel. This channel stands as a testament to London’s resilience. It showcases the city’s commitment to protecting its people and infrastructure.
The River Lee Flood Relief Channel flows between Ware and Stratford. Its construction began in 1947. This followed a period of major flooding. The channel became fully operational in 1976. It was designed to manage and redirect floodwaters. The channel incorporates existing watercourses, lakes, and newly constructed channels. The channel also feeds the Lee Valley Reservoir Chain.
The worst flood in the River Lee Valley’s recorded history struck in March 1947. The winter of 1946 to 1947 was extremely severe. Continuous heavy snow fell. When a thaw began, the rivers rose rapidly. The River Lee’s flow was twenty times its normal level. Widespread flooding began. Water levels did not return to normal until March 19. The flooding shut down the Lea Bridge Waterworks for nine days. This was the first shutdown in its 200-year history. The floodwaters contaminated the water supply for 1.25 million people. An area the size of 4000 football pitches was flooded. Hundreds of homes were flooded. Transport was seriously disrupted.
The 1947 floods prompted the Lee Conservancy Catchment Board to act. They started work on a flood alleviation scheme. This led to the River Lee Flood Relief Channel. The channel was built between 1950 and 1976. It was designed to cope with the 1947 flood level.
Early flood defenses were rated to withstand a 100-year flood. This means a flood level expected to occur only once in 100 years. The 1947 flood was estimated as a 1.4 percent occurrence. The channel was initially built to cope with this level.
Since completion in 1976, there have been no major flood events in the Lea Valley. However, the river system was nearly full in 1987, 1993, and 2000. Over time, the level of protection has declined. In some areas, it now offers only 2 percent protection. In others, it offers 5 percent protection. The Environment Agency is looking at ways to maintain the flood defenses.
At Ware, the channel is part of the Lee Navigation. It flows through Hardmead Lock and Stanstead Lock. These locks have automatic sluice gates. At Feildes Weir, there is a parallel channel. The channel skirts Glen Faba Lake. It passes under Dobbs Weir Road. It enters the Nazeing Meads lake complex. Continuing under Nazeing Road, the channel flows through Holyfield Lake. It merges with the old River Lea at Fishers Green. It flows into the Horsemill Stream. The water runs along the Royal Gunpowder Mills. It passes through the David Stoker sluice. The channel runs parallel with the Lee Navigation. It flows under the A121 road and the M25 motorway. It is joined by Cobbins Brook. Then it passes through Newman’s Sluice.
The channel crosses Rammey Marsh. It forms the eastern boundary of the former Royal Small Arms Factory. Further downstream, the channel merges with the River Lee. It becomes the concrete-banked River Lee Diversion. It skirts the King George V Reservoir and the William Girling Reservoir. The river forms the boundary between Enfield and Waltham Forest. It flows under the North Circular Road. It crosses Tottenham Marshes. It passes close to several reservoirs. Flowing under Forest Road and the Gospel Oak to Barking line, it skirts the Walthamstow Reservoirs. It passes under Coppermill Lane and the Lea Valley Line. It approaches Lea Bridge Road. It crosses Hackney Marshes. It joins the Old River Lea near the New Spitalfields Market. Passing under the Eastway road and the A115 road, it meets the Waterworks River. The channel continues through the Prescott Channel and Bow Creek. It reaches the Thames at Leamouth.
The River Lee Flood Relief Channel stands as a vital piece of infrastructure. It protects countless homes and businesses. It remains a crucial element in London’s ongoing flood management strategy.