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Planning Advice Note PAN 69
Planning and Building Standards Advice on Flooding
APPENDIX A -
FLOODING ISSUES IN SCOTLAND: SUMMARY OF MAIN RESPONSIBILITIES/ACTIONS
Landowners and occupiers
- Primary responsibility for flood protection and insurance.
- Can reduce risk and damage to property
Scottish Executive
- National Policy on Flood Prevention and Flood Warning
- Provision of resources and guidance to enable authorities to address flooding
- National Planning Policy (SPP)7 Planning and Flooding and Planning Advice
SEPA
- Discretionary powers for the provision of Flood Warning for Scotland.
- Operation of 42 local flood warning schemes in Partnership with the Local Authorities and the Police.
- Operation of Floodline including provision of 24 hour Floodwatch cover for all of Scotland by monitoring of data from river levels, rainfall, tide predictions and weather forecasts.
- Advice to local Authorities on flood risk for planning purposes.
- Advice to Local Authorities on flood prevention
- Provision of information in response to public queries on flood risk areas and properties.
- Preparation of RBMP and submission to Scottish Ministers under WEWS Act
Legislation:
- The Environment Act 1995
- The Water Environment and Water Services Act 2003 (WEWS Act)
LOCAL AUTHORITIES:
- Town and country planning
- Interpretation and enforcement of the building regulations
- Convening Flood Liaison and Advice Groups
- Assessment of watercourses in non agricultural areas for conditions likely to pose a flood risk.
- Maintenance of watercourses
- Discretionary powers to promote flood prevention schemes
- Management of flood prevention schemes
- Management of flood prevention and defence schemes
- Work with the Police, Fire and Rescue services in response to severe flooding.
- Ensure road gullies are operational (except trunk roads)
- Deal with road closures (except trunk roads)
- Co-ordination of reception centres for people evacuated from their homes and arrange temporary accommodation if appropriate.
- Emergency planning / co-ordination of the aftermath of flood.
Legislation and National policy:
- Scottish Planning Policy (SPP) 7 - Planning and Flooding
- Building (Scotland) Regulations 2004
- Flood Prevention (Scotland) Act 1961
- Flood Prevention and Land Drainage (Scotland) Act 1997
- Coast Protection Act 1949
- Local Government & Housing Act 1989
- Local Government (Scotland)Act 1973 s.84
- Roads (Scotland) Act 1984
- Civil Protection in Peacetime Act 1986
POLICE
- Responsible primarily for saving life, rescue and recovery
- Receive flood warnings from SEPA
- Co-ordination of the agencies involved in the rescue phase of an incident.
- Involvement in the evacuation process
- Responsible for traffic control within the immediate area of an incident.
FIRE BRIGADE
- Assistance in mitigation of damage wherever possible
- Involvement in the evacuation process
HYDRO-ELECTRIC OPERATORS
- Management of the storage and release of water in their reservoirs.
- Communication with SEPA during flood events.
- In some specific schemes issues flood warnings.
SCOTTISH WATER
- Manage the discharge of surface water that enters its drainage systems
- Work in partnership with the local authority and emergency services to alleviate any flooding of foul sewers and the impact of this flooding
- Maintain water supply and drainage infrastructure
- Repair flood damaged mains and deal with any flooding caused by bursts
- Manage the storage and release of water supply reservoirs
- Liaise with SEPA, local authorities and the emergency services during a flood event
- SuDS vested in Scottish Water under WEWS Act
Legislation:
- Water Industry (Scotland) Act 2002
- Sewerage (Scotland) Act 1968
APPENDIX B -
CLIMATE CHANGE
Summary of Climate Change research for Scottish Executive by Werritty, Black, Duck, Finlinson, Thurston, Shackley and Crichton - February 2000 and August 2001.
Current predictions of climate change suggest that over the present century Scotland will become warmer and wetter, sea level will rise and the number of storms around the coast will increase. As a result, the threat of flooding both inland and around the coast will increase damaging Scotland's economy and society. Transport links, housing, the public water supply and commercial properties are especially vulnerable to such an increase in flooding. Although land owners are primarily responsible for flood protection, local and central government also have a role in reducing the adverse impact of floods.
Frequency and Severity of Flooding in Scotland
Inspection of the longest river flow records reveals considerable variation in the size and frequency of floods year on year making it difficult to identify trends. Across most of Scotland, however, the number of floods peaked during the 1980s and 90s especially in the west due to more storms coming in off the Atlantic. In the north an earlier peak was reached in the 1950s. Since 1989 most of Scotland's largest rivers have reported their highest recorded flows. During these 'flood rich' periods it is clear that floods of a given size were more common, although it is less clear whether the size of the largest floods increased. Whether, over the last 15 years this increase in flooding has been due to climate change is still being debated, but it is consistent with 'flood rich' periods in the past and increased flooding in the future given current estimates of climate change.
Flooding along the coast depends on sea-level, storm surges and whether or not the storms coincide with high tides. Changes in sea-level and storm frequency and severity can thus have a significant impact on coastal flooding. It is now generally accepted that global sea levels have risen by 1-2 mm per year during the last century with Aberdeen reporting a rise of nearly 70 mm during this period. More generally, changes in sea level around Scotland's coast varies depending on continued uplift of the land following the melting of the last ice sheet 10,000 years ago and changes in the amount of water stored in the world's oceans. International authorities reckon that half the rise in global sea levels in the twentieth century was due to thermal expansion of the oceans, a view locally questioned by one authority for the seas around Scotland. Sea level rise represents one part of the coastal flood threat, but more important is the role of storm surges especially when they coincide with high tides. At present it is unclear whether or not coastal storms are becoming more frequent, but the flood levels reached by current 50 year and 100 year storms can be estimated to determine the current flood risk.
Future Severity and Magnitude of Flooding
Flood risks due to both watercourse and coastal flooding are expected to increase during the 21st Century. For river flooding, changes have been estimated using climate change scenarios developed by the Met Office's Hadley Centre. These scenarios cover a range of emissions effects scenarios. Under the Low and Medium low scenarios, increases in the size of floods by the 2080s are likely to be less than 10% for most of Scotland. However, under the Medium high and High scenarios, the same floods may be 20% larger. In especially sensitive river basins what is now a one in 50-year flood on average could, by the 2080s, become as frequent as a one in 20-year flood. However, these changes can only be indicative: it is difficult to separate out the effects of natural climatic variability from those due to human activity, and natural variations are sure to continue affecting our climate in the future.
In coastal areas, future changes in flood risk are estimated from rising sea levels and the size of storm surges. Sea level rises ranging from more than 300 mm to 80 mm have been predicted around Scotland's coasts by 2050. Flooding of coastal land and property normally takes place when storm surges occur, although the largest surge effects can be expected to occur only infrequently. Nevertheless, the effects of combining sea level rise with estimated storm surge effects lead to most of the Scottish coastline up to 4 - 5 m becoming vulnerable to low-risk coastal flooding by the 2050s, unless adequately protected by defences. Again, uncertainty in the scientific community reflects the difficulty of making precise estimates of future coastal flood risk.
Economic Impacts
Without taking into account the protection offered by flood defences, more than 93,000 properties are presently at risk of coastal flooding, while a further 77,000 are at risk of river flooding. Properties located in the following coastal areas (the Carse of Gowrie, the lower Forth estuary, the lower Clyde estuary), inland areas (the lower Tay, Earn and Isla, the lower Kelvin) and urban areas (Paisley, Cathcart, Kirkintilloch and Kilmarnock) are especially vulnerable. Some 6.7% of Scotland's prime agricultural land is also vulnerable. In the coastal zone, these assessments are based on areas lying below the 5 m contour, while inland, flood risk areas have been estimated using assessments based on maps produced by the Scottish Environment Protection Agency (SEPA).
The increases in flood risk imply increases in future damage, unless the flood hazard is appropriately managed. Against a background of average annual flood damages in Scotland in the region of 20 million today, it is estimated that losses may increase by 27% (in 2020) by 68% (in 2050) and by 115% (in 2080) due to climate change. These figures are first-order approximations and take no account of present or future levels of protection offered by flood defences.
Werritty, Black, Duck, Finlinson,
Thurston, Shackley and Crichton
APPENDIX C -
WATER FRAMEWORK DIRECTIVE - LEGISLATIVE ISSUES
The WFD Directive 2000/60/EC applies to all water in the natural environment - that is all rivers, lochs, estuaries and coastal waters as well as water under the ground. The basic objectives to be achieved as set out in Article 4(1) can be summarised as follows:
- prevent deterioration in the status of surface water bodies;
- protect, enhance and restore all bodies of surface water with the aim of achieving good surface water status by 2015;
- prevent deterioration of the status of groundwater bodies;
- protect, enhance and restore all bodies of groundwater with the aim of achieving good groundwater status by 2015;
- prevent or limit the input of pollutants to groundwater and reverse any significant and sustained upward trend in the concentration of pollutants in groundwater;
- comply with European wide measures against priority and priority hazardous substances; and
- achieve compliance with any relevant standards and objectives for protected areas.
The Water Environment and Water Services (Scotland) Act sets out new arrangements for the protection of the water environment and changes how new connections to the public water and sewerage infrastructure are to be funded.
The water environment provisions of the Act (Part 1) make provision and enable provision to be made for or in connection with implementing Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy ("the Directive").
Article 1 of the Directive sets out the main outcomes that it is intended to deliver. These are to be realised through the achievement of the environmental objectives set out in Article 4.
In addition, there is flexibility for Member States to take account of social, economic or wider environmental considerations by applying other objectives where it would be infeasible or disproportionately expensive to achieve the basic objectives. The circumstances in which these alternative objectives may apply are set out in the rest of Article 4.
The Directive requires Member States to put in place systems for managing their water environments, based on natural river basin districts and underpinned by extensive environmental monitoring and scientific investigation, called "river basin management". It further requires Member States to take account of the need to recover the costs of water services as a way of encouraging the sustainable use of water resources.
The Directive repeals and replaces a number of older EC water Directives and incorporates the remaining existing water Directives (the Bathing Water, Nitrates and Urban Waste Water Treatment Directives) into its framework through its protected areas provisions. The 'Natura' Directives on the protection of Habitats and Birds are also linked to this Directive by virtue of the protected area provisions.
APPENDIX D -
DEVELOPMENT AT RISK OF FLOODING: PLANNING AUTHORITY CONSULTATIONS AND SEPA RESPONSES ON PLANNING APPLICATIONS
Responsibilities
1. Planning authorities are required to consult the Scottish Environment Protection Agency (SEPA) before granting planning permission "where it appears to the planning authority that the development is likely to result in a material increase in the number of buildings at risk of being damaged by flooding". (The Town and Country Planning (General Development Procedure) (Scotland) Order 1992 Article 15 (SI 1992/224 as amended by SI 1996 No. 467 (S.36)) (The GDPO).
2. SEPA has the function of "...assessing, as far as it considers it appropriate the risk of flooding in any area of Scotland" and the following statutory duty: "if requested by a planning authority to do so, SEPA shall on the basis of such information as it holds with respect to the risk of flooding in any part of the authority's area, provide the authority with advice as to such risk." The Environment Act 1995, Section 25
3. Any planning authority which proposes to grant planning permission for development "where SEPA has advised against the granting of planning permission or has recommended conditions which the planning authority do not propose to attach to the planning permission" must notify the Scottish Ministers. The Town and Country Planning (Notification of Applications) (Scotland) Direction 1997, Schedule, paragraph 14. The accompanying Circular (4/1997), paragraph 9, however, clarifies this by stating that notification is required when "a planning authority intend to approve a planning application contrary to advice from SEPA that there is a risk of flooding".
4. These provisions clearly give SEPA a role in advising planning authorities in relation to certain applications. They do not give SEPA the power to decide any such applications. The relevant parts of the 1997 Direction, as clarified by paragraph 9 of the accompanying Circular 4/1997, simply require planning authorities to notify the Secretary of State (now the Scottish Ministers) of any applications which the planning authority intend to approve contrary to advice from SEPA that there is a risk of flooding. Although it is not the function of SEPA to determine planning applications, it will give planning authorities clear advice where it considers that there is a significant flood risk and that notification to the Scottish Ministers is necessary if the planning authority intend to grant planning permission. The Planning Authority has to take SEPA's representations into account.
SEPA Responses to Planning Authority Consultations
5. The detailed consultation arrangements are set out in a SEPA-Planning Authority Protocol and under its provisions SEPA's responses will depend on the particular circumstances of each case as follows:
(i) SEPA holds no data pertaining to flooding on this site and therefore is unable to comment on the flood risk relating to this application.
(ii) SEPA considers that better information should be provided by the applicant in a Flood Risk Assessment. (Generic guidance on the content, format and standards of a flood risk assessment is in Annex B of the Protocol.
(Responses (i) and (ii) will frequently be combined)
(iii) On receipt of a Flood Risk Assessment SEPA will audit the assessment and provide its own advice on flood risk based on the information in the assessment.
(iv) SEPA's advice on flood risk will include, as appropriate, the risk to the site, upstream and downstream impact, assessment of any mitigation measures, any comments on habitats issues and sustainability considerations such as climate change.
(v) If SEPA is of the view that the application should be notified to the Scottish Ministers, it will respond by saying that "the site in question has a risk of flooding and it follows that to allow development to proceed may place property or persons at serious risk. In the event that the planning authority proposes to grant planning permission contrary to this advice on flood risk the application must be notified to the Scottish Ministers as per the Notification of Applications Direction 1997."
6. SEPA will endeavour to express the confidence attached to any statement of risk with appropriate qualifying statements related to the nature, source and type of information upon which an assessment is based.
7. The full text of the Protocol is available at SEPA's website http://www.sepa.org.uk/pdf/policies/41.pdf It was issued in September 2000 and within the context of SPP 7 its principles still apply. This appendix summarises some key points but should not be interpreted as definitive.
REFERENCES AND FURTHER READING
Arun District Local Plan, adopted 2003, available at www.esrarundc.co.uk
'AUDACIOUS' Programme, see www.eng.brad.ac.uk/audacious
Boston Borough Local Plan, First Deposit Draft, March 2004, available at www.pcgraphics.uk.com/BOSTON/instructfr.html
Cargill, A. et al. 'Flash flood on the Craigie Burn, Perth, Scotland', Weather Vol.59, No1, January 2004
CIRIA, Sustainable urban drainage systems: design manual for Scotland and Northern Ireland, 2000
City of Edinburgh Council, Development Quality Handbook - Planning and Flooding, August 2001
Clackmannanshire Council, Planning and Flooding Supplementary Advice Note, available at www.clacksweb.org.uk/document/advnote9.pdf
DTLR (with Scottish Executive et al), Preparing for Floods - February 2002, (does not have an ISBN number) http://www.safety.odpm.gov.uk/bregs/floods/index.htm
Environment Agency, Fluvial Freeboard Guidance Note, 1999 - for more details see www.eareports.com/ea/rdreport.nsf/0/ccb8d16014bb808c802569220043484e?OpenDocument
Fleming G., 'Flood Estimation Handbook', 2000
Foresight Project, Foresight Reports, for more information, see www.foresight.gov.uk/fcd.html
Institution of Civil Engineers, 'Learning to Live With Rivers', 2001 available at www.ice.org.uk/downloads//ICEFlooding.pdf
North East Scotland Flooding Advisory Group, Drainage Impact Assessment: Guidance for Developers and Regulators,
www.aberdeencity.gov.uk/acc/pdf/planning/planning/drainage-impact.pdf
ODPM/DETR, Accessible Thresholds in New Housing: guidance for house builders and designers, The Stationery Office, 1999
Ove Arup, River Tay Catchment Study, September 1994
Scottish Executive, PAN 61: Planning and Sustainable Urban Drainage Systems, 2001, available at www.scotland.gov.uk/about/Planning/advice.aspx
Scottish Executive, Scottish Planning Policy (SPP) 7: Planning and Flooding, 2004, available at www.scotland.gov.uk/library5/planning/spp7-00.asp
Scottish Executive, Climate Change: Review of Levels of Protection Offered by Flood Prevention Schemes' UKCIP02 update (2003), available at www.scotland.gov.uk/publications
Scottish Executive, Policy for Architecture for Scotland, 2001
Spelthorne Borough Local Plan, adopted 2001 can be viewed at www.spelthorne.gov.uk/environment---planning/planning/env-planning-localplan.htm
The Town and Country Planning (Development by Planning Authorities) (Scotland) Regulations 1981 (as amended), 1981 SI No 829 (S.85)
GLOSSARY
Brownfield land - land which has previously been developed. The term may encompass vacant or derelict land; infill sites; land occupied by redundant or unused buildings; and developed land within the settlement boundary where further intensification of use is considered acceptable. (SPP 3)
Culvert - a structure with integral sides, soffit and invert, including a pipe that contains a watercourse as it passes through or beneath a road, railway, building, embankment etc, or below ground.
Detention pond - a basin constructed to store water temporarily to attenuate flows.
Drainage assessment - a statement of the drainage issues relevant to a proposal and the suitable means of providing drainage. The length and detail should be proportionate to the issues. As appropriate it may include existing drainage systems and problems, infiltration, groundwater, surface water flow, foul and storm water disposal, SuDS and drainage related flooding issues (may also be called a Drainage Impact Assessment). See also PAN 61 paragraphs 23 - 24.
Flood Liaison and Advice Group (FLAG) - a non statutory advisory group of public and private sector representatives, convened by Councils to share concerns and knowledge and to provide advice on a wide range of planning and other flooding issues in an informal setting. FLAGs were formerly called Flood Appraisal Groups under the 1995 NPPG. The new name better describes their roles.
Flood plain - the generally flat areas adjacent to a watercourse or the sea where water flows in time of flood or would flow but for the presence of flood prevention measures (also called the geographical flood plain).
Flood prevention measures - works including walls, new channels, embankments and flood water storage areas. Usually components of a flood prevention scheme (see below).
Flood prevention scheme - a scheme of flood management measures under the Flood Prevention (Scotland) Act 1961.
Flood risk assessment - an assessment carried out to predict and assess the probability of flooding for a particular site or area and recommend mitigation measures including maintenance.
Flood warning system - SEPA services giving general alerts (Flood Watch) for the whole of Scotland and Flood Warnings for specific areas only.
Freeboard allowance - a height added to the predicted level of a flood to take account of the height of any waves or turbulence and the uncertainty in estimating the probability of flooding.
Functional flood plain - the areas of land where water flows in times of flood which should be safeguarded from further development because of their function as flood water storage areas.
Greenfield land - land which has never previously been developed, or fully restored formerly derelict land which has been brought back into active or beneficial use for agriculture, forestry, environmental purposes or outdoor recreation. (SPP 3)
GDPO - The Town and Country Planning (General Development Procedure) (Scotland) Order 1992 (as amended). Statutory Instrument 1992 No. 224 (S.18). London HMSO.
Public drainage system - the drainage systems which are the statutory responsibility of the roads and water authorities.
Sustainable Drainage Systems - also called Sustainable Urban Drainage Systems, SuDS describes a range of techniques for managing the flow of water run-off from a site by treating it on site and so reducing the loading on conventional piped drainage systems.
Washland - an alternative term for the functional flood plain which carries the connotation that it floods very frequently.
Watercourse - all means of conveying water except a water main or sewer (see Flood Prevention (Scotland) Act 1961.
Water table- the level of ground water below which the ground is saturated.
WEWS Act - Water Environment and Water Services (Scotland) Act 2003.
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