Baseline Document

The PLA's "Baseline Document" was published in June 2007. This document therefore contains information relevant to the integrity of the Thames Estuary and Marshes SPA (Special Protection Area) and Ramsar site, Benfleet and Southend Marshes SPA and Ramsar Site, and the Holehaven Creek SSSI (Site of Special Scientific Interest).

In preparing the PLA's Baseline Report, a data-gathering exercise was carried out. Much data had already been collated by the PLA as part of the Maintenance Dredging Framework. It should be emphasised that the Baseline is based on a desk study of existing and readily available data only (as specified in the draft protocol) and no original survey work has been carried out as part of this exercise. However, through the PLA's Maintenance Dredging Framework, considerable amounts of survey and monitoring data associated with the dredging operations have been gathered.

In addition, the data-gathering exercise has deliberately focused on those environmental parameters that potentially could be affected by maintenance dredging and are of relevance to the integrity of the SPA. These include the following:

• coastal processes and morphology;
• sediment quality;
• water quality;
• intertidal ecology;
• ornithology;
• and noise (where this is limited to potential disturbance of feeding or roosting birds).

The presumption on which the protocol is based is that maintenance dredging will continue in line with present established practice. The Baseline Document has been prepared on the premise that existing practice is part of the functioning of the existing system (i.e. part of the baseline environment and the way it functions). Thus the Baseline Document forms a basis for any future assessment of changes in operations, and is therefore an important tool in the management of any future dredging operations in the tidal Thames.

The preparation of this baseline has involved limited external consultation to date and hence the document itself is considered to be a draft, suitable for discussion with statutory consultees and stakeholders. In addition to the protocol needs, consideration has also been given to the potential impacts on one specific SSSI area, namely Holehaven Creek, in recognition that this may, in future, also be incorporated into the SPA under the Conservation (Natural Habitats etc) Regulations 1994.

A full copy of the Baseline Document is available here (PDF file - 1.36 mb).

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