CO4 Criteria for Coastal Protection and Sea Defence Works Policy
Proposals for new coastal protection and sea defence works will be permitted subject to the following criteria:
(i) the works are necessary to protect life, existing built development or fixed capital assets which cannot be relocated inland;
(ii) other options for achieving the same end have been considered, including managed retreat and other soft engineering techniques;
(iii) allowance has been made for sea level rise;
(iv) impacts on sediment movement within the same sedimentary cell have been examined and minimised;
(v) impacts on landscape character and visual quality have been minimised, particularly within Areas of Special Landscape Value and along the undeveloped part of the coastline;
(vi) the works safeguard sites of international, national and special local importance for nature conservation and earth science on both the landward and seaward sides of the coast;
(vii) impacts on the archaeological resource are identified and assessed to minimise potential loss or damage.
(viii) the works preserve and enhance public access to the coastline, and do not impede navigation;
(ix) satisfactory measures are proposed to minimise the environmental impact of any construction activity; and
(x) the works do not increase the risk of coastal erosion or flooding elsewhere.
Reasoned justification :
20.27 In the Mersey Estuary, a large proportion of the waterfront now consists of the vertical walls of promenades, Docks and private, industrial premises. In the Dee Estuary, a sandstone wall was constructed at Gayton, but is now rarely reached by the tide. North of this, the Dee Cliffs at Thurstaston, are vulnerable to erosion and the resultant land loss is a serious threat to the recreational activities which take place on the cliff tops. However, this has to be balanced against the ecological status of the cliffs, because their value as a Site of Special Scientific Interest lies in the plant successions resulting from erosion. Further north again, at West Kirby and Hoylake, there are promenades and a Marine Lake which can be overtopped by high tides.
20.28 Coast protection and sea defence structures exist along the entire north Wirral coast. The Wallasey Embankment protects low-lying land, and small island breakwaters at Leasowe and New Brighton are designed to encourage deposition and thus raise beach levels.
20.29 There is growing world-wide concern about the possible impact of sea level rises resulting from global warming. In the Wirral context, the Flood Defence Division of the Ministry of Agriculture, Fisheries and Food, considers that the best estimate of sea level rise for the North West Region of the Environment Agency is 4.0 millimetres each year or 0.2 metres over 50 years; and for the Welsh Region of the Environment Agency, 5.0 millimetres each year or 0.25 metres over 50 years. It is, therefore, considered that only limited areas of Wirral, such as the Gayton Marsh area, are at risk from tidal flooding as a result of sea level rise.
20.30 Projects for new flood defence works require planning permission and are covered by the Town and Country Planning (Assessment of Environmental Effects) Regulations 1988 (SI 1199). Improvement works have deemed planning permission but are subject to the similar Land Drainage Improvement Works (Assessment of Environmental Effects) Regulations 1988 (SI 1217). Coast protection works require planning permission and are subject to environmental assessment under the Town and Country Planning (Assessment of Environmental Effects) (Amendment) Regulations 1994 (SI 677).
20.31 Policy CO4 is, therefore, intended to ensure that all the potential impacts of sea defence and coastal protection works are taken into account. In particular, it establishes the principle that new defence protection works should only be constructed where they are necessary to protect life, existing built development or other fixed capital assets. The desirability of preserving the character and amenity of the undeveloped coast means that in these areas, the emphasis should be on natural sea or coastal defences and allowing the coast to adjust to changing conditions. This approach will also safeguard the acknowledged nature conservation importance of much of the undeveloped coastline.