Ministerial guidelines
The Planning System and Flood Risk Management: Guidelines for Planning Authorities
Flood Zones A, B and C, the sequential approach and the Justification Test for development in areas at risk of flooding.
Department of the Environment, Heritage and Local Government and the Office of Public Works · November 2009 · 81 pages
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- Key Messages Flooding and Development Management Planning authorities should apply the sequential approach in aiming to avoid development in areas at risk of flooding, through the development management process. Planning applications will, where appropriate, need to be accompanied by a detailed flood risk assessment to be considered by planning authorities in determining applications. Development within flood risk areas, that would be defined as inappropriate as set out in chapter 3, but which are considered to be necessary to meet the objectives of proper planning and sustainable development, will be subject to the Justification Test. Most flood risk issues should be raised within strategic assessments undertaken by local authorities at the plan-making stage. Therefore, as more plans are reviewed and zoning reconsidered, there should be less need for development management processes to require detailed flood risk assessment. The role of good development management Development management for flooding should be based on sound strategy, policies and objectives within the development plan and LAP where appropriate, setting out the basis for considering planning applications in principle and in detail. Where plans have been adopted before publication of these Guidelines, planning authorities should use the flood risk information available to them to identify the flood zones within their area. They should then ensure that planning applicants submit any necessary flood risk assessment so that flood risk issues within these flood zones can be taken into account in accordance with these Guidelines. Notwithstanding the availability of flood zone maps and a SFRA, the applicant is primarily responsible in the first instance for assessing whether there is a flood risk issue and how it will be addressed in the development they propose. Where flood risk may be an issue for any proposed development, a more detailed flood risk assessment should be carried out appropriate to the scale and nature of the development and the risks arising. The detailed Sitespecific Flood Risk Assessment should quantify the risks and the effects of any necessary mitigation, together with the measures needed or proposed to manage residual risks. Information on site-specific flood risk assessments and potential sources of information are contained in Appendix A. 5.1 5.2 43 Guidelines for Planning Authorities The Planning System and Flood Risk Management
- Stages of development management In essence, the 2007 DEHLG Development Management Guidelines identify 5 stages in the development management process as follows: :: Pre-application; :: Lodgement; :: Assessment; :: Decision; and :: Appeals. Pre-application and identification of flood risk The pre-application stage is critical to the consideration of flood risk in the planning application. It is the responsibility of the applicant at this stage and in the first instance to gather relevant information sufficient to identify and assess all sources of flood risk and the impact of drainage from the proposal. In addition planning authorities should ensure that applicants are made aware of any flood risk issues and of the need for them to submit an appropriate flood risk assessment. Pre-application discussions will be particularly important in identifying the broad range of issues affecting a site and present an opportunity for the planning authority to make clear to applicants that an appropriate flood risk assessment should be carried out as part of the application preparation process. Where flood issues are present, the planning authority should highlight the policies and objectives of the development plan in relation to flood risk and, if available information on flood zones. 5.4 5.5 5.6 5.3 Non-residential ground-floor use in a waterside apartment scheme 44 5
- Ideally, at this preliminary stage, development proposals being put forward by applicants for pre-planning discussion should show the location, broad nature and extent of a proposed development including, where appropriate, the provision of adequate development-free, riparian strips for river maintenance. Where flood risk is present, applicants preparing development proposals, should be advised of the importance of addressing flood risk by adopting a sequential approach in terms of location of uses in areas of lower risk, the consideration of less vulnerable use types and other mitigation through design measures. Sustainable drainage should be integral to the design and formulation of proposals at this stage. Lodgement Any known flood history on or affecting the application site must be declared on the application form, as required by the Planning and Development Regulations 2006. However, an area with no history of flooding does not mean that it is not at risk from flooding. An application for permission in an areas at risk from flooding should be accompanied, where necessary, by an appropriate Site-specific Flood Risk Assessment, having been identified at the pre-application stage from sources of information listed in Appendix A. Flood risk assessment at the site-specific level in areas at risk of flooding is required for all planning applications, even developments appropriate to the particular flood zone. However, the detail of such a flood risk assessment will depend on the level of risk and scale of development. Therefore, small developments, with low risk, will be able to address the issue in a summary manner. The site specific flood risk assessment follows the initial risk assessment stages introduced in chapter 2 and described in more detail in Appendix A. The scope of the flood risk assessment will depend on the type and scale of development and the sensitivity of the area. It will also depend on whether SFRA has been carried out by the planning authority on the development plan in accordance with these Guidelines. 5.7 5.8 Permeable paving detail 45 Guidelines for Planning Authorities The Planning System and Flood Risk Management
- The key outputs from a site-specific Flood Risk Assessment will depend on the level of detail within the Strategic Flood Risk Assessment of the development plan/local area plan. A site specific flood risk assessment should provide the information detailed in Appendix A but in general should include: Plans showing the site and development proposals and its relationship with watercourses and structures which may influence local hydraulics; Surveys of site levels and cross-sections relating relevant development levels to sources of flooding and likely flood water levels; Assessments of: - All potential sources of flooding; - Flood alleviation measures already in place; - The potential impact of flooding on the site; - How the layout and form of the development can reduce those impacts, including arrangements for safe access and egress; - Proposals for surface water management according to sustainable drainage principles; - The effectiveness and impacts of any necessary mitigation measures; - The residual risks to the site after the construction of any necessary measures and the means of managing those risks; and - A summary sheet which describes how the flood risks have been managed for occupants of the site and its infrastructure. :: :: :: 5.9 Detention basin and public open space, Carrickmines, Dublin 46 5
- For further information regarding the basic requirements of the Flood Risk Assessment see Appendix A. Given the potential complexity of the processes inherent in a site specific flood risk assessment and the likely costs to an applicant in preparing one, planning authorities should carefully evaluate calling for site specific flood risk assessments as a result of pre-application consultations or within the determination of a planning application when there are fundamental objections to the development on other grounds. Applicants should not have to undergo unnecessary delay or expense preparing such an assessment if a refusal is probable. Further information on surface water management and basic requirements for the drainage aspects of flood risk assessment are contained in Appendix A. The flood risk assessment should be incorporated into any EIA process where one is required. The flood risk assessment should be approved/certified by a competent person, qualified and experienced in flood risk assessments (see Appendix A). Processing and assessment The planning regulations and the Development Management Guidelines (2007) set out in detail the appropriate procedures for processing an application. All applications with flood risk issues should be forwarded to the relevant technical sections of the planning authority for comment and at the earliest possible opportunity. Where these issues are complex in nature, the planning authority may wish to engage appropriate external advice. In terms of flooding, it will be important to notify prescribed bodies of the application, e.g. the fisheries board, if mitigation measures to river banks are proposed and to assess the application, based on the full range of planning considerations of any submissions made. Assessment of the application should be based principally on the policies and detailed objectives of the development plan, with flood risk considered along with the full range of planning considerations for the application. In assessing development proposals in areas at risk of flooding, planning authorities should adopt a risk-based sequential and balanced approach that gives priority to development in areas of lowest risk, while at the same time allowing consideration of appropriate and necessary development, through the use of the sequential approach based on flood zones and application of the Justification Test. 5.11 5.10 5.12 5.13 5.14 47 Guidelines for Planning Authorities The Planning System and Flood Risk Management
- 5.15 Application of the Justification Test in development management Where a planning authority is considering proposals for new development in areas at a high or moderate risk of flooding that include types of development that are vulnerable to flooding and that would generally be inappropriate as set out in Table 3.2, the planning authority must be satisfied that the development satisfies all of the criteria of the Justification Test as it applies to development management outlined in Box 5.1 below. When considering proposals for development, which may be vulnerable to flooding, and that would generally be inappropriate as set out in Table 3.2, the following criteria must be satisfied: The subject lands have been zoned or otherwise designated for the particular use or form of development in an operative development plan, which has been adopted or varied taking account of these Guidelines. The proposal has been subject to an appropriate flood risk assessment that demonstrates: The development proposed will not increase flood risk elsewhere and, if practicable, will reduce overall flood risk; The development proposal includes measures to minimise flood risk to people, property, the economy and the environment as far as reasonably possible; The development proposed includes measures to ensure that residual risks to the area and/or development can be managed to an acceptable level as regards the adequacy of existing flood protection measures or the design, implementation and funding of any future flood risk management measures and provisions for emergency services access; and The development proposed addresses the above in a manner that is also compatible with the achievement of wider planning objectives in relation to development of good urban design and vibrant and active streetscapes. The acceptability or otherwise of levels of residual risk should be made with consideration of the type and foreseen use of the development and the local development context. Note: See section 5.27 in relation to major development on zoned lands where sequential approach has not been applied in the operative development plan. Refer to section 5.28 in relation to minor and infill developments. 1. 2. (i) (ii) (iii) (iv) 48 5 Box 5.1 Justification Test for development management (to be submitted by the applicant)
- Where development has to take place in areas at risk of flooding following the application of these Guidelines, the risks should be mitigated and managed through the location, lay-out and design of the development to reduce such risks to an acceptable level. The residual risks to the proposed development should be considered carefully, taking into account the type of development and its vulnerability, how flood risks to the occupants will be managed, insurance provision, scale of the risks and the provision of flood defence works. A precautionary approach would be to set floor levels above the 1% flood level ignoring the moderating effects of flood defences. However, within an existing built-up area the approach above may not produce an appropriate streetscape and therefore for proposed developments with a lower vulnerability, flood resistant and flood resilient construction methods to reduce the impact of flooding would be appropriate. In this situation the flood risk assessment should be thorough and measures to manage these residual risks carefully detailed. More information on flood risk management by design is available in Appendix B. In all cases, a precautionary approach should be taken to allow for uncertainties in data and risk assessment procedures and to enable adaptability to future changes in risk, including the effects of climate change. Where new development in flood risk areas is approved, details of the flood risk, mitigation measures and residual risk should be supplied by the planning authority to the major emergency management committee (MEMC) of the relevant local authority for inclusion in their major emergency risk assessment. Flood risk assessment and EIS Flood risk may constitute a significant environmental effect of a development proposal that in certain circumstances may trigger a sub-threshold EIS. Flood risk assessment should therefore be an integral part of any EIA. An appropriate assessment of the impacts of the development on sensitive habitats under the EU Habitats Directive and reiterated in Circular NPWS 1/08 must also be factored in to the evolution of developments that potentially affects sites designated under the EU’s Natura 2000 programme. 5.16 5.17 5.18 49 Guidelines for Planning Authorities The Planning System and Flood Risk Management
- Making the decision Planning legislation (Schedules of Planning and Development Act, 2000 as amended) allows for the framing of conditions to deal with flood risk and the refusal of permission for reasons of flood risk without attracting compensation. The Department’s 2007 Development Management Guidelines (DEHLG, 2007) provide guidance on the appropriate nature and type of conditions. Where flood risk is an issue, the planning authority may consider granting permission subject to conditions to ensure that the Justification Test is satisfied. Overall, conditions should deal with any residual risk and should be guided by the development management objectives set out in the development plan. Only in very limited circumstances should conditions which require the provision of significant drainage systems, major alterations, flood related structural work or significant relocation of development be attached to planning permissions. Ideally, all these matters should be adequately dealt with in the pre-application and processing stages such that any necessary work(s) are included as an integral part of the development proposal. In most cases, conditions will be required to amend, clarify or further detail flood mitigation measures. These might include, for example, the removal of barriers or buildings on a water flow route, the requirement for flood resistant street furniture and fittings, or, the requirement for detailed flood resistance or flood resilience measures for buildings. Conditions relating to maintenance may include, for example, the regular inspection, maintenance and repair of local or secondary flood defences such as earth bunds or elements of the sustainable drainage system such as swales, basins or ponds. Conditions relating to the ongoing monitoring of flood defences and overall flood risk may also be appropriate. Conditions may also be required in dealing with potential flood issues in minor residential development and residential extension proposals. 5.19 5.20 5.21 5.22 50 5 Gully and sink, Stockholm
- Where the risk to people remains significant after mitigation measures, conditions may require arrangements to be put in place by the developer and in the case of multi-unit developments, the relevant management company to ensure the installation, operation and maintenance of an adequate flood warning system and the preparation and regular updating of an emergency plan for all users of the site. Such plans should be guided by A Framework for Major Emergency Management (2006) and be consistent with the Major Emergency Plans of the relevant Principal Response Agencies (An Garda Síochána, the HSE and the local authority). These conditions should be consistent with the provisions of the Development Management Guidelines. Permission should be refused where flood issues have not been, or cannot be, addressed successfully and where the presence of unacceptable residual flood risks remain for the development, its occupants and adjoining property. Only developments which are consistent with the overall policy and technical approaches of these Guidelines should be permitted. Where development proposals include the construction or amendment of bridges, culverts or similar structures the applicant should have regard to the requirements of Section 50 of the Arterial Drainage Act, 1945. It is recognised that flood map data sets, predictive models of flood risk and a strategic assessment of the flood risks across a county or city area may not have been undertaken at the time that a planning decision is required. This does not mean that the sequential approach should not be applied or that a Justification Test need not be undertaken. A precautionary approach should be applied, and either the application should be refused on grounds of prematurity where a review of a development plan is imminent or a flood risk assessment should be undertaken, and the Justification Test applied following advice in paragraphs below. 5.23 5.24 5.25 5.26 Retention pond, Stepaside, Dublin 51 Guidelines for Planning Authorities The Planning System and Flood Risk Management
- 5.27 Assessment of major proposals for development in areas of flood risk pending implementation of these Guidelines From a flood risk management perspective, proposals fitting into this category should be considered as though the land was not zoned for development. In such situations the applicant should be required, in consultation with the planning authority, to prepare an appropriate SFRA and to meet the criteria for the Justification Test as it applies to development plan preparation. The planning authority must then assess the proposal against the Justification Test as it applies to the development management process. Where the information is not sufficient to fully assess the issues involved, the development should not be approved on the basis of flood risk and / or on the grounds of prematurity prior to addressing flood risk as part of the normal review of the development plan for the area. Assessment of minor proposals in areas of flood risk Applications for minor development, such as small extensions to houses, and most changes of use of existing buildings and or extensions and additions to existing commercial and industrial enterprises, are unlikely to raise significant flooding issues, unless they obstruct important flow paths, introduce a significant additional number of people into flood risk areas or entail the storage of hazardous substances. Since such applications concern existing buildings, the sequential approach cannot be used to locate them in lower-risk areas and the Justification Test will not apply. However, a commensurate assessment of the risks of flooding should accompany such applications to demonstrate that they would not have adverse impacts or impede access to a watercourse, floodplain or flood protection and management facilities. These proposals should follow best practice in the management of health and safety for users and residents of the proposal. 5.28 52 5
Source Department of the Environment, Heritage and Local Government and the Office of Public Works: The Planning System and Flood Risk Management: Guidelines for Planning Authorities (November 2009) · Licence the publisher's termsText read from the publisher’s PDF; tables, maps and drawings do not survive as text, and page numbers are the PDF’s (its first page is 1). Check the original before relying on a passage.