The PLA is committed to applying Environmental Impact Assessment (EIA) principles to both its own dredging and dredging by third parties. Each proposed dredging activity is therefore subject to a scientific and environmental assessment.
In the first instance, a standard checklist is used to ensure that the full range of potential environmental issues associated with a particular dredge can be identified, and to determine which issues are likely to be significant. In completing this first step, data provided by the applicant, existing information from previous applications, and the output from the Information Exchange System , are all referred to. In particular, interrogation of the IES should immediately provide an overview of the key environmental characteristics and interests in the area, including any constraints. Further, where potential impacts are identified, the PLA may then consult with the responsible agency. Where the proposed works are within, adjacent to, or likely to affect, a Special Protection Area or Special Area of Conservation, advice will be sought from English Nature and consideration will be given as to whether an Appropriate Assessment is required under the terms of the Habitats Regulations.
The environmental checklist considers potential impacts on:
In all cases, the completed checklist, supplemented with additional information as necessary, forms an important input into the decision making process. However, in cases where the checklist identifies potentially significant environmental impacts, the PLA will consider whether an environmental appraisal or a full Environmental Impact Assessment needs to be prepared under the relevant legislation.
Both the 1994 Habitats Regulations (implementing the 1979 EU Birds Directive and the 1992 EU Habitats Directive) and the Countryside and Rights of Way (CRoW) Act 2000 have implications for the PLA. If the proposed dredging is likely to significantly affect a European site (ie. a Special Protection Area, a Special Area of Conservation) or a Site of Special Scientific Interest, additional requirements are likely to apply.
As a competent authority under the Conservation (Natural Habitats &c.) Regulations 1994, the PLA must carry out an Appropriate Assessment of any plan or project which, either alone or in combination with other plans or projects would be likely to have a significant effect on a European site; and is not directly connected with the mangement of the site for nature conservation. If the Appropriate Assessment identifies that - even with mitigation - the scheme is likely to have an adverse effect on the integrity of the site in question, the PLA must be satisfied that there are no alternatives, and that there are imperative reasons of overriding public interest for the project to proceed. Further, as owner of much of the seabed within the Thames Estuary, the PLA is similarly required under Section 19 of the Habitats Regulations to consult with English Nature and potentially carry out an Appropriate Assessment, before carrying out or agreeing to works within a European Marine Site.
In addition to the above, as a Section 28g Authority under the Wildlife and Countryside Act 1981, as incorporated by the CRoW Act, the PLA is required to conserve and enhance Sites of Special Scientific Interest, ensuring that no damage is caused to such sites due to activities occurring either within or outside of the designated area. Under both these procedures, the information used to inform the assessment process is typically provided by the applicant. Consultation with English Nature will generally also be required.
Consideration will also be given to habitats and species identified as important by the UK Biodiversity Action Plan or the Tidal Thames Habitat Action Plan.
Finally, the 1997 implementation of the 1979 EU Shellfish Waters Directive can already affect decisions on some dredging activities, and it is anticipated that the EU Water Framework Directive could have similar - and potentially more wide-ranging - implications for some of the PLA’s activities and others within the estuary.