B35 Chapter 7 - Environmental Safety

Flood Protection

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7.1

North Norfolk has a coastline that stretches for some 73 km (45 miles), from Holkham in the west to Horsey in the south-east. Parts of the coastline, principally in the Blakeney, Salthouse, Weybourne and Horsey areas are low-lying and are prone to flooding in extreme tidal and weather conditions. Rising sea levels and instances of severe coastal flooding have focused attention on minimising both the risk to life and damage to property. Flood defence, including arterial land drainage, is the responsibility of the Environment Agency (EA). For watercourses which are not designated as main rivers, local authorities have the statutory powers to maintain and improve existing works or construct new works, except in internal drainage districts where the powers rest with the Internal Drainage Boards (IDBs).

7.2

Within North Norfolk the EA, IDBs and the Council are only able to exercise direct but limited control over some activities affecting drainage systems through the use of the Land Drainage Act 1991 and the Water Resources Act 1991, as amended. The Government therefore expects the Council to use its planning powers to guide development away from areas that may be affected by flooding, and to restrict development that would itself increase the risk of flooding or would interfere in the ability of the EA or other bodies to carry out flood control works or maintenance.

Flood Protection Schemes

7.3

The EA currently has two flood defence schemes programmed in North Norfolk.

Broadland Flood Alleviation Strategy

7.4

The EA has undertaken a public consultation exercise and environmental impact assessments for the development of a comprehensive strategy for the protection of the Norfolk Broads from tidal flooding. In April 1994 the Norfolk and Suffolk Local Flood Defence Committee agreed that a Yare Barrier would provide the ultimate form of flood protection for the Broads area but, because of the cost and justification difficulties, that such an option would be deferred. The EA is to proceed with a bank strengthening programme. The study area includes parts of the Local Plan area as well as the Broads.

Happisburgh to Winterton Sea Defences

7.5

This involves the construction of massive rock-armoured offshore wave-break reefs. This is a comprehensive scheme to secure the defences between Happisburgh and Winterton, the most exposed length of the North Norfolk coast. Allied to these works is a beach nourishment and recharge scheme to supplement depleted beach levels.

7.6

Flood defence works, which are included in Schedule 2 of the Town and Country Planning (Assessment of Environmental Effects) Regulations 1988, as amended, require environmental assessment where the proposed works are likely to have significant environmental effects.

7.7

These engineering works, allied to existing flood defences, will reduce the risk of flooding but will not eliminate it completely.

Flood Risk Areas

7.8

Freshwater river flooding (fluvial) can occur in the natural flood plains of rivers and other watercourses, and also in defined washlands. The 'flood plain' is that area of low-lying land next to a watercourse that is liable to flood under certain conditions. 'Washlands' are areas designed and maintained for the storage of flood water. Tidal flooding could occur through a breach in North Norfolk's coastal defences, or overtopping of these defences, and affect low-lying land possibly at some distance from the breach or point of overtopping.

7.9

The aim of the EA in providing defences against both fluvial and tidal flooding is to protect people, property and land to a standard that is practical and appropriate. However, defences cannot be provided to a standard that would eliminate all risk of flood, particularly in extreme weather conditions.

7.10

The risk of flooding also varies over time. Existing sea defences tend to deteriorate, increasing the risk; whereas reconstruction of these defences or new defences reduces the risk. The flood risk issue will become increasingly important given expected sea-level rises, possible increases in storm severity and changes in weather patterns arising from predicted global climate changes. Long term sea-level change may be caused by two factors:

• changes in the volume of water held in the world's oceans caused by such factors as an increase in ocean temperature or the melting of the fresh water stored in ice-caps through global warming; and

• change in the level of the land relative to the sea (sometimes known as isostatic change). In the British Isles this is largely caused by changes in the land surface which are still taking place after the melting of the ice which formed over Scotland during the last glacial period. The removal of the enormous weight of this ice caused the land mass of Scotland to begin to rise while southern England (including East Anglia) suffered a commensurate depression.

7.11

In this context, it is prudent to limit new development in areas at risk from flooding. This approach has two benefits. Firstly, it does not add to the amount of people or property at risk from flooding. Secondly, it means that new development does not reduce the capacity of flood plains or impede the flow of water which would increase the risk of flooding elsewhere.

7.12

In the Pre-Deposit Draft version of the Local Plan the proposals map identified the areas the EA considered to be at risk from flooding from either fluvial or tidal waters. Following public consultation it became evident that the detail and accuracy of the information supplied to the Council was not adequate for the purposes of the Local Plan. Consequently, the proposals map in the Deposit Draft version did not show areas at risk from flooding, and this remains the situation in this adopted version. However, the EA intends to supply local authorities with fully up-to-date and reliable information in the future. When this information becomes available it should be possible to show which areas are at risk from flooding in a subsequent review of the Local Plan.

7.13

In the meantime though, it is still important to control development that may be at risk from flooding. Consequently, the Council will continue to consult with the EA in order to determine whether new development proposals would be likely to increase the risk to life or property.

Policy 46: Flood Risk - expired 27/09/2007
Development proposals will not be permitted where it is considered by the Council, in consultation with the Environment Agency, that there would be a significant increase in risk to life or property from the effects of flooding.

Run-off from New Development

7.14

Impermeable surfaces, such as paved areas, roads and roofs, reduce the ground area that is capable of absorbing rainfall. Consequently, new developments may increase the quantity and the rate at which run-off reaches watercourses. These effects may cause the capacity of the watercourse to be exceeded at times of flood risk, especially where there are culverts, bridges and other artificial or natural restrictions. The consequences of development in the upper parts of a river catchment area may not be apparent in the area within which the development occurs, but they can have a significant effect on areas downstream.

Policy 47: Surface Water Run-Off: Flood Risk - expired 27/09/2007
Development proposals that would increase the risk of flooding as a result of changes in surface water run-off will not be permitted unless it is possible to overcome those problems by attaching a condition to any planning permission granted and/or by the use of a Section 106 Obligation.

Holiday Parks and Caravan and Camping Sites

7.15

Caravan and camping sites can be the subject of special problems at times of flood, whether they are in use year-round or only in the summer-holiday period. The instability of caravans, particularly in tidal flooding and high velocity flood flow conditions, may place their occupants at special risk. These considerations, and their implications for the siting of new caravan pitches and the application of holiday occupancy restrictions, are addressed in Chapter 13: Tourism.

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Coast Protection

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7.16

North Norfolk's coastal cliffs are created from a glacial material that makes them unstable when they have a high water content. This has resulted in slips and slides along the coastline and the general retreat of the cliff line. In some areas coastal landslides or rapid coastal erosion may eventually threaten public safety or cause damage to buildings or structures. The Government's PPG on 'Development on Unstable Land' (PPG 14), published in April 1990, makes it clear that ground instability is a material consideration in deciding planning applications and an important issue to be addressed by local plans. This guidance is reiterated in Annex 1 of PPG 14, dealing with 'Landslides and Planning', published in March 1996.

Coast Protection Strategy

7.17

In December 1990 the Council published a coast protection strategy that represents a coherent approach to future coast protection works. The strategy identifies four categories of future coast protection works.

Category 1: Work which needs to be carried out immediately for safety reasons or to ensure the security of installed defences where they are immediately at risk.

Category 2: Work necessary to ensure the long-term security of the defences.

Category 3: Investigative work required to obtain data in order to understand more fully what is happening along the coast.

Category 4: Work necessary to improve the appearance of the coast and thereby increase the public's use of the beaches as an amenity.

7.18

Coast protection works that are likely to have significant environmental effects now require an environmental assessment under the Town and Country Planning (Assessment of Environmental Effects) Regulations 1988, as amended. These environmental assessments should include an estimate of the effects that the proposed works will have on nature conservation interests and on the natural movement of material along the coast.

Coastal Erosion Risk Areas

7.19

To minimise the undesirable consequences of coastal erosion such as property damage, personal distress to occupants and the degradation of the physical environment, new development in unstable locations is to be resisted.

7.20

In North Norfolk the main causes of coastal erosion are through marine erosion of the cliff base and the presence of underground water. Both forms of erosion lead to landslides of varying magnitudes (see Fig. 8). In some cases these processes have been reduced or even halted by a combination of coast protection and ancillary works. In other areas, where the erosion processes have not been curtailed, erosion rates have reached an average of 2.5m per annum. However, it is important to note that, because landslides are mass movements rather than a gradual process of erosion, erosion rates are calculated by averaging out the effects of landslides over a certain period of time.

7.21

The Government's PPG on 'Coastal Planning' (PPG 20), published in September 1992, states that development should not be allowed to take place in areas where erosion is likely to occur during the lifetime of the building. Consequently, based upon average erosion rates, areas of coastal land that are likely to become unstable within the next 60 years have been identified and are shown on the proposals map. The base date for this information is 1993. These areas have been defined on the basis of the best information available to the Council as Coast Protection Authority. Within these areas development that would be likely to lead to an increase in the number of people at risk, or to a significant increase of risk to property or general infrastructure, will not normally be permitted.

7.22

Erosion rates will continue to be monitored so that, together with the implementation of new coastal defence and associated works, the areas identified as being at risk can be periodically reviewed. Interested parties should contact the Coast Protection Authority to ascertain the latest information in this regard.

7.23

The types of development that will not be permitted by the following policy include any new building other than small extensions or ancillary structures which do not increase the number of people living, working or engaged in leisure activities in the area. Consequently, new dwellings, or extensions to existing dwellings which would increase the number of habitable rooms, will not be acceptable. Temporary open-air uses not requiring the construction of new buildings will normally be acceptable in terms of the policy on risk.

Drainage

7.24

Underground water is a major contributor to coastal erosion whereby changes in water content through heavy rainfall or drainage alteration may increase water pressures, and thus decrease the resistance of the slope to ground movement. New development can exacerbate this process because impermeable surfaces (such as paved areas and roofs) reduce the ground area capable of absorbing rainfall and, thereby, increase the quantity and rate of surface water run-off.

7.25

In some coastal areas sewerage schemes have been implemented that take run-off from both roads and roofs as well as foul sewage (known as a 'combined system') so as to reduce the presence of underground water. Where new development is proposed and combined sewers exist, rainwater discharge should ideally be to the sewer; but in all cases the Coast Protection Authority, in consultation with the EA, will ensure that the change in surface water drainage created by new developments does not exacerbate the processes of erosion that are associated with underground water.

Policy 49: Surface Water Run-Off: Coastal Erosion Risk
Development proposals that are likely to increase coastal erosion as a result of changes in surface water run-off will not be permitted unless it is possible to overcome those problems by attaching a condition to any planning permission granted and/or by the use of a Section 106 Obligation.

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Shoreline Management Plans

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7.26

Shoreline Management Plans are strategic initiatives which examine the management of sustainable coastal defences for a specific length of coast. These plans provide a framework for coordinating the work of the various operating authorities, including the EA and Coast Protection Authorities, in a manner which takes account of natural coastal processes, defence need, environmental considerations, development pressures and current and future land uses.

7.27

The coastline of England and Wales has been divided into eleven cells within which the movement of coarse sediment is largely self-contained. North Norfolk's coastline falls in the cell bounded by The Wash and the River Thames.

7.28

Further divisions into sub-cells are based on the direction of movement of sediment. North Norfolk is affected by two sub-cells and therefore requires the Council's involvement in the preparation and implementation of two management plans:

• the North Norfolk Shoreline Management Strategy, covering the coastline between Snettisham and Sheringham; and

• the Sheringham to Lowestoft Shoreline Management Strategy, covering the coastline between Sheringham and Lowestoft. (The Council is acting as the lead authority for this plan.)

7.29

Consultants were appointed to examine the strategic coast defence options in consultation with interested bodies. Final reports were published in 1996. In the same year the Shoreline Management Plans were approved by the various operating authorities.

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Hazardous Installations

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7.30

Some industrial sites store or use dangerous substances that are capable of causing injury, death or damage. The Notification of Installations Handling Hazardous Substances (NIHHS) Regulations 1982 were introduced in order to identify such potentially hazardous sites, and the Planning (Hazardous Substances) Consents Regulations 1992, as amended, control certain aspects of the use and storage of hazardous substances. The area covered by the Local Plan contains a number of installations handling notifiable substances, including high-pressure natural gas transmission pipelines. Whilst they are subject to stringent controls under existing health and safety legislation, it is still considered prudent to control the kinds of development permitted in the vicinity of these installations.

7.31

The Council has been advised by the Health and Safety Executive (HSE) of consultation distances for each of these installations. In deciding whether to grant permission for a proposed development within these consultation distances, the Council will take account of the advice it receives from the HSE about the risks to the proposed development from the notifiable installation.

7.32

To supplement these consultation arrangements the Local Plan identifies the most important installations (see Fig. 9) and sets out the criteria for the control of development within their vicinities.

Bacton Gas Terminal

7.33

The Bacton Gas Terminal is a notified hazardous installation. Modern technology and safety precautions have reduced the hazardous risk to a very low level but, nevertheless, there remains some risk of accident. For this reason a 'Major Hazard Zone' (MHZ) has been defined by the HSE showing the area within which the effects of a fire or explosion originating at the terminal might be serious. This area is shown on the proposals map.

7.34

In view of the risk, development that singly or cumulatively increases the population, residential or otherwise, within this zone should not be permitted, regardless of its location. Accordingly, it is also not appropriate to increase the risk to holiday-makers in this area by lengthening the period during which holiday caravans, chalets or houses can be occupied.

7.35

The Council also recognises that such developments can serve to limit development opportunities within the terminal itself and, in view of the importance of such an installation to the local and national economy, unnecessary constraints upon its activities should be avoided.

Policy 50: Bacton Gas Terminal
In the Bacton Gas Terminal Major Hazard Zone development proposals that would increase the population present (including visitors) in the Zone at any one time, with the exception of those development proposals directly associated with the operation of the terminal itself, will not be permitted.

Hazardous Pipelines

7.36

The development of hazardous pipelines are subject to the requirements of the Health and Safety at Work etc. Act 1974 which include specific provision for the protection of the public. However, the possibility remains that a major accident could occur at a pipeline and that this could have serious consequences for people in the vicinity.

7.37

In areas adjacent to notifiable gas pipelines, the HSE considers that the risk of harm to people in larger-scale residential, hotel, school and residential institution developments would be so great that planning permission for such proposals should be refused on grounds of safety.

7.38

Other forms of development, and development outside gas pipeline MHZs may also be at risk. Consequently, the Council will continue to consult the HSE on all development proposals in the vicinity of notifiable gas pipelines.

Policy 51: Hazardous Pipelines
Development proposals adjacent to notifiable gas pipelines will not be permitted where the Council, in consultation with the Health and Safety Executive, considers that there would be a significant increase in risk to life or property.

Hazardous Substances Consent

7.39

The Planning (Hazardous Substances) Act 1990, as amended, requires consent to be obtained for the presence of hazardous substances at, or above, specific amounts. These are known as 'controlled quantities'. These controls give the Council the opportunity to consider whether the storage or use of a hazardous substance is appropriate in a particular location, having regard to the risk of an accident and its consequences for people in the surrounding area. The HSE will be consulted on every application for hazardous substances consent and, in view of its acknowledged expertise, any advice from it on hazardous substances will not normally be overridden by the Council.

Policy 52: Hazardous Substances - expired 27/09/2007
Development proposals relating to the storage or handling of hazardous substances will be permitted where the Council, in consultation with the Health and Safety Executive, considers that there would be no significant increase in risk to life, property or nature conservation interests in the surrounding area.

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Aeronautical Safeguarding

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7.40

Certain civil and military aerodromes, selected on the basis of their importance to the national air transport system or for their strategic importance, are officially safeguarded. In North Norfolk, safeguarding areas are identified for Norwich Airport, Cromer Radar, Trimingham (Antingham) Radio, Trimingham (Overstrand) Radio, Neatishead Technical Site, and West Raynham, Sculthorpe and Coltishall aerodromes. Safeguarding maps show which types of planning application should be the subject of consultation with the Civil Aviation Authority or the Ministry of Defence.

7.41

Consultation is usually required for tall buildings or structures within safeguarded areas, or development that might endanger the safety of aircraft by attracting large numbers of birds ('Bird-Strike' hazard). Such developments include: all facilities for the handling, compaction, treatment and disposal of household and commercial wastes; reservoirs and lakes; sewage disposal and treatment works; mineral extraction; and the creation of nature reserves or bird sanctuaries.

7.42

Planning permission will not be refused simply because the proposal is one requiring consultation, nor will new buildings be automatically restricted to certain maximum heights in safeguarded areas. Safeguarding maps are issued by the Civil Aviation Authority or the Secretary of State for Defence and, as with other special consultation areas, are not defined on the proposals map.

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