Environmental impacts – Wildlife
Ants, wild flowers and heavy engineering
Approximately 160km of the track for which we are responsible is above ground and home to flora and fauna including bats, badgers, snakes, birds, insects, plants, and many different trees and flowers.
“We need to ensure that there is a balance between the needs of the railway and those of the vegetation and wildlife,” explains Steve Judd, Tube Lines Environmental Asset Manager. “My team are aware of the different types of wildlife and vegetation on our land and we do all we can to protect them.”
Objectives and statistics |
Policy objective:Conserving and safeguarding flora and fauna. Measuring our progress:• Wildlife surveys were conducted at all depots and sidings in 2006 |
Not surprisingly, essential engineering work and conserving the environment are not always readily compatible. For example, 30 per cent of the work of the P-Way team, responsible for our track replacement programme, is actually earth structure remediation and drainage works - for which vegetation must be cleared.
“Stabilising embankments and cuttings slopes is an important part of maintaining the railway,” explains Ann Joyce, who is responsible for access and environmental issues for P-Way’s Civil Engineering team. “Between April and December 2006 we surveyed 2,385m of cuttings and embankments and carried out nearly 700m of remediation work on the Northern and Piccadilly lines.
“We work to minimise our impact on the environment. Before we start work we survey the site for protected species or species that are of interest, we identify tree preservation orders and where possible we avoid doing clearance work in bird nesting season.”
At one site on the Jubilee line we found some meadow ants. Although they are not rare, we wanted to keep them to maintain the biodiversity of the site. “When we realised they were living in the embankment we worked with contractors to ensure that they were not disturbed,” says Ann.
Once our work is finished, we replace the vegetation with a mixture of trees and plants suitable for each individual site. When trees are not the best solution either for a balanced planting scheme or the operation of the railway, we use shrubs and a mixture of wild flowers and grasses. “Within six to 12 months the sites have re-established themselves,” says Ann, “and best of all, once a slope has been reconstructed, its projected lifespan is about 120 years.”
News in brief |
- A survey carried out by Ecology Consultancy showed that our depots and sidings provide important habitats for flora with special status such as small and pale toadflax, greater celandine, common spotted orchid, longheaded poppy and cornflower as well as protected fauna including badgers, reptiles, slow worms, bats and breeding birds. “This survey of the ecological value of depots and sidings complements one completed in 1999 to assess the nature conservation value of the above-ground trackside areas,” explains Rebecca Brown, Environment Adviser. - All information from the 1999 and 2006 wildlife surveys has been loaded on to our computerised Geographical Information System (GIS), which maps environmental issues, from tree species and wildlife parcels to noise and contaminated land hotspots across all our sites. GIS is available to every employee through our intranet and is proving very helpful for project planning. - Vegetation from DSM’s Acton works now goes onto the site compost heap – and eventually helps the roses to bloom. - An important bat colony living in one of our disused tunnels is thriving. The London Bat Group, which monitors the roost and bat behaviour, reports that the bat population has increased eight-fold in the last three years. - We introduced new signs on sites across our lines in 2006, marking protected trees, badger setts and habitats clearly to prevent accidental damage, as well as highlighting any areas of unwelcome vegetation, such as Japanese knotweed. |
Case Study |
Green roof takes rootWe installed London’s largest single membrane green roof in 2006, designed to blend in with its surroundings. Cutting tree felling to a minimumCareful planning and surveying helped us to reduce vegetation clearance needed for the installation of a new signalling system to a minimum. |
