Canals habitat audit

Canals are artificial waterways constructed for purposes of inland navigation. In London these include The Grand Union Canal (Main Line and Paddington Arm), the Regent's Canal, and the Lee Navigation (incorporating the Hertford Union Canal and the Limehouse Cut).

The London canal network was cut during between 1767 and 1830 to provide a transport link both across London and between London and the industrial towns of the Midlands and the north. Although initially a success, their importance waned with the advent of railways in the latter part of the 19th Century. Although built primarily as arteries for commerce and trade, the creation of a canal system resulted in a network of linear wetlands that provide habitat for a range of wetland species and, in recent years, an increasingly important amenity and recreational resource.

London has approximately 80km of canal corridor covering an area of about 270 ha (see Table 1 and the Map).

The entire London canal network has been designated a Site of Metropolitan Importance for nature conservation as a result of its intrinsic value for wildlife and because it provides public access to nature; the latter is particularly important where canals pass through inner city boroughs.

Redevelopment of canalsides poses an obvious threat if existing habitat is lost to built development or new development results in the replacement of naturally occurring vegetation with unsympathetic landscaping schemes. Increased recreational use of the canals and their environs could result in the threat of increased disturbance to canalside wildlife. The need to maintain the waterway for boat traffic may also increase the threat to wildlife habitat as existing desilting and vegetation clearance regimes may need to be augmented. Repair and repointing of canal walls and other infrastructure prevents plants from gaining a foothold and may reduce the availability of nest sites for birds and roost sites for bats. As with any wetland habitat, pollution of the waterway can result in harm to wildlife.

The London's Waterway Partnership, a consortium of businesses, local authorities, statutory agencies and voluntary sector organisations, has developed a programme to promote and enhance the London canal network. Although its focus is primarily on the regeneration opportunities provided by London's Waterways, environmental protection is one theme of the initiative.

Habitat creation and habitat enhancement schemes have already been implemented throughout the London canal network but many further opportunities exist or may arise as a result or canalside repair, maintenance or redevelopment. The canals link a large number of open spaces and provide a corridor from the Green Belt in to the urban centre of London. Establishing a footpath network along the towpath has increased the opportunity for people's use and enjoyment of this corridor. It could be further enhanced as a wildlife corridor by sympathetic enhancement of the canal corridor and adjoining open spaces.

The accessibility and extensive recreational use of the London waterways provides valuable opportunities for raising awareness of biodiversity issues amongst audiences such as anglers and boaters, who need to be brought into Partnerships to ensure biodiversity conservation is integral to the management of the waterways.