5.10.1The SPPS states that development will not be permitted in areas of the coast known to be at risk from flooding, coastal erosion, or land instability. Strategic subject policy in relation to flooding is set out in Chapter 9.0.
5.10.2Mid and East Antrim has a coastline that extends approximately 65 miles. Whilst much of this is a ‘hard’ coastline, the extent to which it is prone to coastal change, particularly through coastal erosion, is not currently known. Work being led by DfI and DAERA to gather information for the Northern Ireland coastline as a whole is at a very early stage.
5.10.3Past investigations by the Geological Survey for Northern Ireland (GSNI) have identified areas of ‘known’ and historic land instability in Mid and East Antrim. These areas are shown on the GSNI GeoIndex map viewer currently accessible on: http://mapapps2.bgs.ac.uk/GSNI_Geoindex/home.html.
5.10.4It should be noted that not all of these areas are on the coast. Wherever they are defined, there is considerable uncertainty as to whether these areas are currently unstable. Development proposals along the coast should have regard to the Marine Policy Statement and draft Marine Plan for NI, as the consideration of coastal processes is a core policy area.
5.10.5Where development is proposed within the designated areas of ‘known’ and historic land instability, applicants should ensure that early contact is made with GSNI.
CS9 Development at Risk from Land Instability or Coastal Erosion
There is a general presumption against development in known areas of land instability and/or coastal erosion.
A proposal for new built development within a known area of land instability or coastal erosion will not be permitted unless the applicant has demonstrated to the satisfaction of the Council that there are no consequential risks to health and safety.
Where built development is proposed in a known area of land instability or coastal erosion, the applicant will be required to carry out detailed investigations and submit a report along with the planning application to address the following matters:
determine the extent of land instability and /or the extent of land at risk from coastal change; and
identify any remedial measures that would be adequate to permit the development.
Planning Permission will be refused where:
development constraints arising from land instability or coastal processes cannot be sufficiently addressed so as to eliminate risk to health and safety; or
there is insufficient information as to the level of risk and the threat to health and safety; or
where the nature of the investigative work and/or the remedial measures to be employed would be likely to trigger land instability or coastal erosion (or change) risk elsewhere; or
where the nature of the investigative work and/or the remedial measures to be employed would have significant adverse impact on biodiversity, landscape character or archaeology.
Where planning permission is granted, conditions are likely to be imposed to secure the measures necessary to ensure a safe form of development.
Justification and Amplification
5.10.6Given the prevailing level of uncertainty around risk, the policy sets out a presumption against development in areas of ‘known’ risk of land instability. The policy will also apply to areas of ‘known’ risk of coastal erosion in due course, when the information emerges. In order for built development to be approved in these areas, an applicant will need to identify the current extent of instability and demonstrate if any remedial measures, including design and engineering solutions, would be adequate to permit development. In carrying out site investigations, applicants must take account of potential impacts on biodiversity, archaeology and landscape character. Any unresolved threat to health and safety due to instability will preclude development, as will insufficient information about the level of risk.
5.10.7Even where engineering solutions are sufficient to enable safe development, regard will be had to the implications for land instability in other locations. This may apply particularly along the coastline, where hard engineering solutions could potentially interfere with coastal processes and trigger instability elsewhere.
5.10.8GSNI will be consulted on all applications within or close to areas that are ‘known’ to be at risk. Applicants are also advised to consult with GSNI at an early stage.
5.10.9The granting of planning permission does not infer that the land is free from instability. The responsibility for safe development and secure occupancy of any building lies with the developer and/or landowner.