Milestone achieved at Prescott Lock

The step, known as 'tidal lock-out', prevents the influx of tidal flotsam and detritus, reduces the fluctuation in water levels and enables essential repairs to be carried out on the river walls. Importantly, it will also maintain the rivers at a navigable depth for river traffic, from waterbuses and leisure boats to 350-tonne barges carrying construction materials into the Olympic Park.

Funded by the Olympic Delivery Authority, London Thames Gateway Development Corporation, Transport for London, Department for Transport and British Waterways the £20m project is part of a Defra-backed vision to transform the area's waterways for wildlife, people and transport.

Following the works, water levels in the river will continue to rise and fall by up to a metre a day, creating ideal opportunities for establishing habitat features such as reedbeds. These valuable wetland habitats are also being created throughout the Olympic Park to encourage a diverse array of native plants and animals. A 'fish pass' is also being incorporated into the new Prescott Channel structure, enabling a variety of fish species to cross between the river system and the Thames tideway to the south.

Leela O’Dea, British Waterways London, ecologist explains: "The river system in this area has suffered for years from dreadful pollution, particularly from sewage outfalls at Abbey Mills. This project is one element of a series of measures to help us clean up the rivers and give Nature a helping hand in re-establishing a wonderful green corridor through east London. It will also enable us to bring boats back to Stratford for the first time in decades, whilst providing a sustainable mode of transport bringing benefits to the environment."

Construction of the new lock is being managed by British Waterways and undertaken by design and build contractors Volker Stevin Ltd, with a supporting team including Tony Gee & Partners LLP, Bennett Associates, Clague Architects and Weetwood Environmental Engineering. Works began in March 2007 and are due for completion in early 2009, with the first freight barges movements beginning shortly after the end of the Beijing Games. For further information visit www.britishwaterways.co.uk/olympics.