Appendix 5: From London Wildlife Trust

Richmond upon Thames River Biodiversity - Ham/Twickenham Reach

The tidal Thames is London's biggest nature reserve, providing a large and continuous ecological corridor which in many places in Richmond upon Thames also includes important river bank habitats. Over the years water levels and the river channel have changed dramatically through reclamation of the natural floodplain and river bank engineering. However, there are now significant pressures to ensure developments now work with nature rather than force the river into a concrete lined channel.

On the Twickenham side much of the bank is walled, with only a couple of areas of natural bank. On the other side of the river Ham lands provides extensive marsh land and floodplain. It as an increasingly important site for wildlife, particularly with the continuing decline we are seeing in our gardens and across much of the country’s farm land.

Eel Pie Island is one of the islands identified as significant, from a wildlife point of view, by the Environment Agency’s Consultation Document on the "Thames Tideway", published in 1997. This document highlights the need of undisturbed land adjacent to the river as "critical to the lifecycle of many species of wildlife."

This reach of the river is particularly important of bats and a range of birds.

The River Thames & islands and Ham Lands are designated "Sites of Metropolitan Importance for Nature Conservation". Ham Lands is also designated as a Local Nature Reserve.

Threats

Thus the increasing river traffic generated by the pontoon is likely to pose a threat to wildlife, particularly the casual users of hire boats who are more likely to attempt to land on unspoilt river bank sites.

Notes

Wildlife on the River: I understand that EA consent is required for works within 16 metres of the flood defences, any new pontoon would require this consent. They can set requirements relating to the design and size of the structure and will want to know:

If the structure or boats bottom-out

Is there a need for dredging to provide a berth

What impact will increased use of the river have on wildlife and how will these impacts be mitigated/compensated for.

The results of an ecological appraisal and possibly an inter-tidal invertebrate survey.

There may also be a requirement depending on site and size of structure for a hydraulic model to assess impacts on the river flow regime in the area.

John Hatto 31 May, 1999