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HomeMy WebLinkAbout2660030 - F.I. Received Doc. - Flood Risk AssessmentSite Specific Flood Risk Assessment SITE-SPECIFIC FLOOD RISK ASSESSMENT FOR PROPOSED DEVELOPMENT AT COOLMUCKBANE MONAGHAN CO. MONAGHAN Prepared for Eimeer & Wayne Casserly Prepared by Traynor Environmental Ltd Reference Number 25.471 TE Date of Issue 1st September 2026 Belturbet Business Park, Creeny. Belturbet, Co Cavan T: + 353 49 9522236 E: nevin@traynorenv.com www.traynorenvironmental.ie RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 2 Issue Date Details Prepared by Checked/Approved by 1 11th August 2026 Draft Report Francis Mc Mahon Environmental Consultant Nevin Traynor Environmental Scientist 2 1st September 2026 Final Report Francis Mc Mahon Environmental Consultant Nevin Traynor Environmental Scientist Project Title: Flood Risk Assessment Client: Eimeer & Wayne Casserly Office Reference: 25.471 TE Status: Final Report Date: 1st September 2026 Technical Reviewer Signature Nevin Traynor Environmental Scientist Date: 1st September 2026 Traynor Environmental Belturbet Business Park Creeny Belturbet Co. Cavan H14AY94 Tel: 049 9522236 Email: info@traynorenvironmental.ie © This Report is the copyright of Traynor Environmental Ltd. Any unauthorized reproduction or usage by any person other than the addressee is strictly prohibited. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 3 CONTENT 1.0 INTRODUCTION 4 1.1 Terms of Reference 4 1.2 Statement of Authority 4 1.3 Purpose 4 1.4 Definition of Flood Risk 5 1.5 Stages of the Flood Risk Assessment 5 1.6 Likelihood of Flooding 6 1.7 Definition of Flood Zones 6 2.0 The Planning System and Flood Risk Management Guidelines OPW 8 2.1 The Planning System and Flood Risk Management Guidelines (2009) 8 2.2 Vulnerability and Land Use 9 2.3 Stages of Flood Risk Assessment 10 3.0 SITE DESCRIPTION & LOCATION 11 3.1 Site Description 11 3.2 Site Levels and Topographical Survey 12 4.0 GEOLOGY & HYDROGEOLOGY 13 4.1 Soils and Subsoils 13 4.2 Hydrology 13 4.3 Affected Water bodies 16 5.0 FLOODING HISTORY 17 5.1 Published information 17 5.2 Historical OSI Maps. 17 5.3 OPW National Flood Hazard Mapping 18 5.4 OPW Flood Mapping 19 5.5 CFRAM Fluvial Flood Risk Map 20 6.0 LEVEL 3 – DETAILED FLOOD RISK ASSESSMENT 22 6.1 Hydraulic assessment 22 6.2 Discussion of Findings 32 6.3 Proposed Finished Floor Level 33 6.4 Access and Egress 34 7.0 ASSESSMENT OF FLOODING MECHANISMS 35 7.1 Preamble 35 7.2 Initial assessment 35 7.3 Flood mechanisms 36 8.0 JUSTIFICATION TEST 38 9.0 DESIGN FLOOD LEVELS 39 9.1 Potential for the project to contribute to off-site flooding 39 9.2 Residual Risk 40 10.0 CLIMATE CHANGE 42 10.1 Assessing flood risk in the context of climate change 42 11.0 CONCLUSION 43 APPENDIX A - HYDROLOGICAL CALCULATIONS 45 APPENDIX B - TOPOGRAPHICAL SURVEY 47 APPENDIX C - OPW FLOOD MAP 49 RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 4 1.0 INTRODUCTION 1.1 Terms of Reference This Site-Specific Flood Risk Assessment (SSFRA) has been prepared on behalf of Eimeer and Wayne Casserly in support of a planning application for the construction of a storey-and-a-half dwelling, single-storey domestic garage, wastewater treatment system, relocation of the existing wastewater treatment system serving the neighbouring dwelling, new entrance, connection to the group water scheme and all associated site development works at Coolmuckbane, Co. Monaghan. The proposed development site is hereafter referred to as “the Site”. This assessment has been prepared in response to Item 4 of the Further Information request issued by Monaghan County Council in relation to Planning Reference 26/60030. Item 4 requests that the applicant address the potential risk of fluvial flooding to the proposed development, including the potential for adverse impacts on the proper functioning of the wastewater treatment system, and demonstrate that the development will not increase flood risk elsewhere, displace floodwaters off-site, obstruct important flow paths or give rise to unacceptable residual flood risk. 1.2 Statement of Authority This report and assessment have been prepared and reviewed by suitably qualified professionals with appropriate experience in flood risk assessment, hydrology, hydraulic assessment and surface-water drainage. The key personnel involved in the preparation and review of this assessment are as follows: • Nevin Traynor, BSc (Hons) – Environmental Scientist with experience in flood risk assessment, hydrology and hydraulic assessment. • Francis McMahon, MSc (Hons) – Engineer specialising in hydrology, flood risk assessment, drainage and Sustainable Drainage Systems (SuDS), with experience in the preparation and review of flood-risk and drainage assessments. 1.3 Purpose The purpose of this SSFRA is to assess the potential flood risk to and from the proposed development at Coolmuckbane, Co. Monaghan, with particular regard to the fluvial flood-risk concerns raised by Monaghan County Council under Item 4 of the Further Information request. The assessment considers the available flood-risk information, historical flood records, site characteristics, topography, nearby watercourses, the proposed site layout, wastewater treatment infrastructure and proposed surface-water drainage arrangements. In particular, the assessment seeks to determine whether the proposed development: • will be at unacceptable risk of flooding; • could result in the displacement of fluvial floodwaters or increase flood risk on adjoining or downstream lands; • could obstruct or impede important flood-flow paths; • could give rise to residual flood risks that cannot be managed to an acceptable level; and • could be subject to flooding that would adversely affect the proper functioning of the proposed wastewater treatment system. The assessment has been prepared in accordance with the principles of The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009) and is intended to demonstrate compliance with the flood-risk requirements of the Further Information request. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 5 1.4 Definition of Flood Risk Flood risk is a combination of the likelihood of a flood event occurring and the potential consequences arising from that event. Flood risk is therefore generally expressed using the following relationship: Flood Risk = Likelihood of Flooding × Consequences of Flooding To fully assess flood risk, it is necessary to understand where floodwater originates, how it may move through or across a site, and the receptors that may be affected. This is commonly described using the Source–Pathway–Receptor model, as illustrated in Figure 1. Figure 1: Source–Pathway–Receptor Model The principal sources of flooding include rainfall, rivers and streams, groundwater and, where relevant, elevated sea levels. Potential flood pathways include watercourses, drains, sewers, overland-flow routes and floodplains. Potential receptors include people, property, infrastructure and the environment. The source, pathway and receptor must therefore be considered together, along with the vulnerability and exposure of the receptor, in order to determine the potential consequences and overall level of flood risk. 1.5 Stages of the Flood Risk Assessment The level of detail and complexity of a flood risk assessment should be proportionate to the scale, nature and potential flood risk associated with the proposed development. For the purposes of this Site-Specific Flood Risk Assessment, the following information and assessment stages have been considered: • available information relating to historical flooding within the Site and surrounding area; • available OPW flood-risk mapping and flood-event records; • site-specific topographical and watercourse survey information; • the location, elevation and nature of the proposed development; • identification of potential sources, pathways and receptors of flooding; • hydrological estimation of design flows for the adjacent watercourse; • site-specific hydraulic assessment of the surveyed watercourse cross-sections; • assessment of the potential influence and partial blockage of downstream hydraulic structures; • assessment of the 1% AEP, 1% AEP plus climate-change allowance and 0.1% AEP fluvial flood events; • consideration of pluvial, groundwater and drainage-related flood risk; • consideration of potential flood risk to the proposed wastewater treatment system; RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 6 • assessment of the potential for the development to displace floodwaters, obstruct flood-flow paths or increase flood risk elsewhere; and • consideration of residual flood risk and the requirement for appropriate mitigation measures. 1.6 Likelihood of Flooding The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009) describe the likelihood of flooding in terms of the probability of a flood of a particular magnitude occurring or being exceeded in any given year. Flood probability is generally expressed as an Annual Exceedance Probability (AEP) or, alternatively, as an equivalent return period. For example, a 1% AEP flood event has a 1% probability of occurring or being exceeded in any given year and is commonly referred to as the 1-in-100-year flood event. Similarly, a 0.1% AEP event is commonly referred to as the 1-in-1,000-year flood event. The relationship between Annual Exceedance Probability and return period is summarised in Table 1 below. Table 1: Correlation Between Return Period and Annual Exceedance Probability (AEP) Return Period Annual Exceedance Probability (%) 1 in 10 years 10% 1 in 20 years 5% 1 in 50 years 2% 1 in 100 years 1% 1 in 200 years 0.5% 1 in 1,000 years 0.1% The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009) define three flood zones based on the probability of flooding from rivers and the sea. These flood zones provide the basis for applying the sequential approach to development and determining the appropriateness of different development types from a flood-risk perspective. 1.7 Definition of Flood Zones 1.7.1 Flood Zone A Flood Zone A comprises lands where the probability of flooding is highest: • Fluvial flooding: greater than 1% AEP (1 in 100 years); or • Coastal flooding: greater than 0.5% AEP (1 in 200 years). Most forms of development are considered inappropriate within Flood Zone A. Development should generally be avoided and should only be considered in exceptional circumstances where the requirements of the Development Management Justification Test can be satisfied. Water-compatible development may be considered appropriate within this zone. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 7 1.7.2 Flood Zone B Flood Zone B comprises lands where the probability of flooding is moderate: • Fluvial flooding: between 1% AEP (1 in 100 years) and 0.1% AEP (1 in 1,000 years); and • Coastal flooding: between 0.5% AEP (1 in 200 years) and 0.1% AEP (1 in 1,000 years). Highly vulnerable development, including dwelling houses, is generally considered inappropriate within Flood Zone B unless the requirements of the Development Management Justification Test can be satisfied. Less vulnerable development and water-compatible development may be considered appropriate within Flood Zone B, subject to an appropriate Flood Risk Assessment demonstrating that flood risk to and from the development can be adequately managed. 1.7.3 Flood Zone C Flood Zone C comprises lands where the probability of flooding from rivers or the sea is low: • Fluvial flooding: less than 0.1% AEP (1 in 1,000 years); and • Coastal flooding: less than 0.1% AEP (1 in 1,000 years). Flood Zone C therefore comprises lands that are outside Flood Zones A and B. Development, including highly vulnerable development such as dwelling houses, is generally considered appropriate within Flood Zone C from a fluvial and coastal flood-risk perspective. However, consideration must still be given to other potential sources of flooding, including pluvial, groundwater, drainage and overland-flow flooding. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 8 2.0 THE PLANNING SYSTEM AND FLOOD RISK MANAGEMENT GUIDELINES This Site-Specific Flood Risk Assessment has been prepared in accordance with The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009) and the associated Technical Appendices. The Guidelines provide the principal framework for the consideration of flood risk within the planning process and promote a sequential, risk-based approach to the location and assessment of development. 2.1 The Planning System and Flood Risk Management Guidelines (2009) The Guidelines provide guidance on the identification, assessment and management of flood risk in the planning process. They advocate a precautionary and risk-based approach, with the primary objective of avoiding inappropriate development in areas at risk of flooding. The sequential approach seeks to: • Avoid development in areas at risk of flooding where possible; • Substitute less vulnerable development where avoidance is not possible; and • Mitigate and manage flood risk where development in a flood-risk area can be justified. The application of the sequential approach is informed by the identification of Flood Zones A, B and C, based primarily on the probability of fluvial and coastal flooding. These Flood Zones are used together with the vulnerability classification of the proposed development to determine whether a particular development type is appropriate at a given location and whether a Development Management Justification Test is required. The indicative relationship between the Flood Zones is illustrated in Figure 2. Figure 2: Indicative Flood Zones (DoEHLG/OPW, 2009) Table 2: Definition of Flood Zones and Associated Annual Exceedance Probabilities Flood Zone Definition Annual Exceedance Probability A Probability of flooding from rivers and the sea is highest Fluvial: greater than 1% AEP (1 in 100 years). Coastal: greater than 0.5% AEP (1 in 200 years). B Probability of flooding from rivers and the sea is moderate Fluvial: between 1% AEP (1 in 100 years) and 0.1% AEP (1 in 1,000 years). Coastal: between 0.5% AEP (1 in 200 years) and 0.1% AEP (1 in 1,000 years). C Probability of flooding from rivers and the sea is low. Flood Zone C covers all areas of the plan which are not in zones A or B Fluvial and Coastal: less than 0.1% AEP (1 in 1,000 years). RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 9 2.2 Vulnerability and Land Use The Guidelines recognise that the potential consequences of flooding depend partly on the vulnerability of the proposed land use. Development types are therefore classified as Highly Vulnerable Development, Less Vulnerable Development or Water- Compatible Development. The proposed development includes a dwelling house and associated wastewater treatment infrastructure. Dwelling houses are classified under the Guidelines as Highly Vulnerable Development. The relevant development vulnerability classifications are summarised in Table 3. Table 3: Classification of Development Vulnerability Vulnerability Class Land uses and types of development which include: Highly Vulnerable development (including essential infrastructure) Garda, ambulance and fire stations; hospitals; emergency access and egress points; schools; dwelling houses; student halls of residence and hostels; residential institutions; caravans and mobile- home parks; dwellings designed or adapted for elderly persons or persons with impaired mobility; and essential infrastructure, including certain water, wastewater, transport and utility infrastructure. Less vulnerable development Retail, leisure, warehousing, commercial and industrial development; non-residential institutions; certain holiday or short-let caravan and camping uses; agriculture and forestry; waste treatment other than landfill and hazardous waste; mineral working and processing; and local transport infrastructure. Water-compatible development Flood-control infrastructure; docks, marinas and wharves; navigation facilities; certain waterside activities; water-based recreation and tourism excluding sleeping accommodation; lifeguard and coastguard stations; amenity space; outdoor sports and recreation; and associated essential facilities. The vulnerability classification of the proposed development is considered in conjunction with the applicable Flood Zone to determine whether the development is appropriate and whether a Development Management Justification Test is required. The relationship between development vulnerability and Flood Zone is summarised in Table 4. Table 4: Development Vulnerability and Flood Zone Compatibility Vulnerability Class Flood Zone A Flood Zone B Flood Zone C Highly Vulnerable development Justification test Justification test Appropriate Less vulnerable development Justification test Appropriate Appropriate Water-compatible development Appropriate Appropriate Appropriate The proposed dwelling constitutes Highly Vulnerable Development. The site-specific assessment demonstrates that the proposed development area is located within Flood Zone C. In accordance with the Guidelines, Highly Vulnerable Development is considered appropriate within Flood Zone C, and a Development Management Justification Test is therefore not required. However, where Highly Vulnerable Development is demonstrated to be located within Flood Zone C, the development is considered appropriate from a fluvial and coastal flood-risk perspective, and a Development Management Justification Test is not required. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 10 Notwithstanding this, an appropriate Site-Specific Flood Risk Assessment remains necessary to consider other potential sources of flooding and to demonstrate that the development will not increase flood risk elsewhere or give rise to unacceptable residual flood risk. 2.3 Stages of Flood Risk Assessment The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009) recommend a staged approach to Flood Risk Assessment, whereby the level of assessment undertaken is proportionate to the nature and extent of the identified flood risk. The three stages are summarised as follows: • Stage 1 – Flood Risk Identification: Identification of whether there are potential flooding or surface-water management issues affecting the proposed development that warrant further investigation. • Stage 2 – Initial Flood Risk Assessment: Identification and assessment of the potential sources of flooding, review of available flood-risk information and determination of whether a more detailed assessment is required. • Stage 3 – Detailed Flood Risk Assessment: A detailed and, where appropriate, quantitative assessment of flood risk to the proposed development, the potential for the development to affect flood risk elsewhere, and the effectiveness of any proposed flood-risk management or mitigation measures. The Guidelines recognise that not all stages will necessarily be required in every case and that the appropriate level of assessment should be proportionate to the identified flood risk, the nature of the proposed development and the extent of any mitigation measures required. For the proposed development at Coolmuckbane, the initial assessment identified the Drumrutagh Stream as a potential source of fluvial flood risk requiring further site-specific assessment, particularly having regard to the matters raised under Item 4 of the Further Information request. Accordingly, this SSFRA has progressed to a Stage 3 Detailed Flood Risk Assessment. The detailed assessment includes site- specific hydrological estimation of design flows, surveyed watercourse cross-sections, quantitative hydraulic assessment of the Drumrutagh Stream, consideration of the 1% AEP, 1% AEP plus climate-change allowance and 0.1% AEP events, and a sensitivity assessment of partial blockage of the downstream culvert. The assessment also considers pluvial, groundwater and drainage-related flood risk, the proposed wastewater treatment system, potential flood-flow paths, the potential for displacement of floodwaters or increased flood risk elsewhere, and residual flood risk. The level of assessment undertaken is therefore considered proportionate to the proposed development and sufficient to enable an informed determination of the proposed development from a flood-risk perspective. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 11 3.0 SITE DESCRIPTION & LOCATION 3.1 Site Description The proposed development site is located at Coolmuckbane, Co. Monaghan and extends to approximately 0.35 hectares (3,500 m²). The Site currently comprises agricultural grassland within a rural setting and is bounded by the L1402 Local Prim ary Road to the north, agricultural lands to the south and west, and an existing residential dwelling to the east. The Drumrutagh Stream is located to the south of the proposed development and represents the principal watercourse considered in this Site-Specific Flood Risk Assessment. The proposed development comprises the construction of a storey-and-a-half dwelling, single-storey domestic garage, new wastewater treatment system and polishing filter, relocation of the existing wastewater treatment system serving the adjoining dwelling, new vehicular entrance, connection to the existing group water scheme and all associated site development works. Vehicular access to the Site will be provided via a new entrance onto the L1402 Local Primary Road. Surface-water runoff from the proposed dwelling, hardstanding areas and site entrance will be collected through a dedicated drainage system and discharged to an engineered soakaway. The soakaway has been assessed in accordance with BRE Digest 365 using site-specific infiltration testing and has been designed to provide appropriate storage and infiltration capacity for runoff generated by the proposed development. . Figure 3: Site Layout & levels RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 12 3.2 Site Levels and Topographical Survey The submitted site layout incorporates existing spot levels across the proposed development site. The proposed dwelling has a Finished Floor Level (FFL) of +100.000 relative to the local site datum, while existing ground levels within the immediate development area generally range between approximately +99.73 and +100.31 relative to the same local datum. The available spot levels indicate that the proposed dwelling is located on relatively level ground, with only minor variation in existing ground levels across the immediate development area. The proposed development has been positioned having regard to the existing topography of the Site. The proposed wastewater treatment system and polishing filter are located to the west and south-west of the proposed dwelling. Surface-water runoff from the proposed dwelling, hardstanding areas and site entrance will be collected through a dedicated drainage system and discharged to the proposed engineered soakaway within the Site. Existing boundary hedgerows will be largely retained as part of the proposed development. A separate Site Characterisation and Site Suitability Assessment has been undertaken for the proposed on-site wastewater treatment and disposal system in accordance with the EPA Code of Practice – Domestic Waste Water Treatment Systems (Population Equivalent ≤10), 2021. Groundwater was encountered at approximately 1.80 m below ground level within the trial hole, while no bedrock was encountered to the investigated depth of 2.10 m below ground level. No surface-water ponding was observed within the proposed wastewater treatment and polishing-filter area during the site assessment. The Site Characterisation Assessment concluded that the Site is suitable for the proposed wastewater treatment and disposal system, subject to the specified treatment arrangement and maintenance of the required unsaturated separation to groundwater. The proposed system is to maintain a minimum of 0.90 m of suitable unsaturated percolating material between the base of the lowest part of the gravel distribution bed and groundwater at all times. The Drumrutagh Stream, located to the south of the proposed development, represents the principal potential source of fluvial flood risk considered in this assessment. The relationship between the proposed development levels, surveyed watercourse geometry and predicted design flood levels is assessed quantitatively in Section 6. Table 6: Site Elevations Location Level (m) Proposed Finished Floor Level +100.000 Highest surveyed spot level +100.310 Existing spot levels around dwelling +99.730 to +100.110 Lowest surveyed spot level shown +99.730 Proposed surface water drainage Engineered soakaway Site area Approx. 3,500 m² (0.35 ha) Note: The levels presented above are relative to the local site datum used on the submitted planning drawings and should not be interpreted as metres Ordnance Datum (mOD). The hydraulic assessment presented later in this report expresses predicted water levels in mOD. A precise surveyed conversion between the local site datum and Ordnance Datum has not been established within the information available for this assessment. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 13 4.0 GEOLOGY & HYDROGEOLOGY The geological and hydrogeological characteristics of the Site have been assessed through a review of available published information from the Geological Survey Ireland (GSI) and the Environmental Protection Agency (EPA), together with the findings of the site-specific EPA Site Characterisation and Site Suitability Assessment undertaken for the proposed wastewater treatment and disposal system. The geological and hydrogeological setting is relevant to this Flood Risk Assessment principally in relation to groundwater conditions, groundwater flood risk and the proposed infiltration-based surface-water and wastewater disposal arrangements. 4.1 Soils and Subsoils Geological Survey Ireland (GSI) mapping indicates that the Site is underlain by sandstone till (Devonian/Carboniferous), with bedrock comprising Tournaisian sandstone, mudstone and limestone. No alluvial deposits are mapped within the Site boundary. While the absence of mapped alluvium does not, in isolation, determine the extent of historical flooding, it provides no geological indication that the proposed development area forms part of an established alluvial floodplain. The separate EPA Site Characterisation Assessment undertaken at the Site recorded no bedrock within the trial hole to the investigated depth of approximately 2.10 m below ground level. Groundwater was encountered at approximately 1.80 m below ground level. 4.2 Hydrogeology and Groundwater Groundwater conditions at the Site have been considered having regard to available GSI and EPA information and the findings of the site-specific EPA Site Characterisation Assessment. Available GSI mapping identifies the Site as being within an area of high groundwater vulnerability. Groundwater vulnerability relates to the relative ease with which contaminants may migrate from the ground surface to the underlying groundwater system and should not, in itself, be interpreted as an indication of groundwater flood risk. The EPA Site Characterisation Assessment encountered groundwater at approximately 1.80 m below ground level. No groundwater emergence, waterlogging or surface-water ponding was identified within the proposed wastewater treatment and polishing-filter area during the site assessment. The assessment also identifies the general direction of groundwater flow as being towards the south. The Site Characterisation Assessment concluded that the Site is suitable for the proposed wastewater treatment and disposal system, subject to the specified treatment arrangement and compliance with the requirements of the EPA Code of Practice – Domestic Waste Water Treatment Systems (Population Equivalent ≤10), 2021. The proposed wastewater disposal arrangement is required to maintain a minimum of 0.90 m of suitable unsaturated percolating material between the base of the lowest part of the gravel distribution bed and groundwater at all times. Accordingly, while groundwater is present beneath the Site and represents an important environmental receptor, the available site-specific information does not identify evidence of groundwater emergence or a significant groundwater- flooding mechanism affecting the proposed development area at ground level. On the basis of the available information, groundwater flood risk to the proposed development is considered low. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 14 Figure 4: Groundwater/Aquifer Map From the GSI Groundwater Aquifer Map Site is classified as Rf - Regionally Important Aquifer - Fissured bedrock Figure 5: Vulnerability Map From the GSI Vulnerability Map Site is classified as High RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 15 Figure 6: Bedrock Map From the GSI Bedrock Map Site is classified as Tournaisian sandstone, mudstone, limestone Figure 7: Teagasc soil Map From the Teagasc Subsoil Map Site is classified as Sandstone till (Devonian/Carboniferous) RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 16 4.3 Affected Water bodies The principal surface-water receptor relevant to this Flood Risk Assessment is the Drumrutagh Stream, located to the south of the application site. The stream represents the principal potential source of fluvial flooding considered in this assessment and has therefore been subject to site-specific hydrological and hydraulic assessment in response to Item 4 of the Further Information request issued by Monaghan County Council. The proposed development is set back from the Drumrutagh Stream and comprises a dwelling, domestic garage, wastewater treatment and disposal infrastructure, access and associated site-development works. No works, culverting, diversion or obstruction of the Drumrutagh Stream are proposed as part of the development. Surface-water runoff from the proposed roof areas, hardstanding and site entrance will be collected through a dedicated drainage system and discharged to an engineered soakaway designed in accordance with BRE Digest 365 using site-specific infiltration testing. Accordingly, there will be no direct discharge of development-generated surface-water runoff to the Drumrutagh Stream. The proposed wastewater treatment and disposal system has been subject to a separate Site Characterisation and Site Suitability Assessment undertaken in accordance with the EPA Code of Practice – Domestic Waste Water Treatment Systems (Population Equivalent ≤10), 2021. The assessment concluded that the Site is suitable for the proposed wastewater treatment and disposal arrangement, subject to implementation of the specified treatment system and maintenance of the required unsaturated separation to groundwater. The potential for fluvial flooding associated with the Drumrutagh Stream, including the 1% AEP, 1% AEP plus climate-change allowance and 0.1% AEP events, is assessed quantitatively in the following sections of this report. The assessment also considers whether the proposed development could displace floodwaters, obstruct existing flood-flow paths, increase flood risk on adjoining or downstream lands, or adversely affect the proper functioning of the proposed wastewater treatment system. Figure 8: Ground Waterbodies Risk From the EPA Map Site Shows the Ground Waterbodies Risk as Not at risk Monaghan Town IEGBNI_NB_G_012 RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 17 5.0 FLOODING HISTORY As part of the flood-risk identification process, available historical and published flood information has been reviewed to establish whether there is evidence of previous flooding affecting the Site or its immediate surroundings. The review has included available OPW flood-risk and historical flood records, together with historical Ordnance Survey mapping and site-specific information. The findings of this review are summarised below. 5.1 Published Information 5.1.1 OPW National Preliminary Flood Risk Assessment The Office of Public Works (OPW) is the lead State agency for flood-risk management in Ireland and is the national competent authority for implementation of the EU Floods Directive. Available OPW flood-risk information has been reviewed as part of this assessment to identify potential historical or mapped flood risk affecting the proposed development site and surrounding area. 5.1.2 OPW National Flood Hazard Mapping The OPW National Flood Hazard Mapping information provides records of historical flood events based on available reports, photographs, local-authority information and other documented sources. A review of the available historical flood information identified no recorded historical flood event within the proposed development site. The absence of a recorded flood event does not, in isolation, demonstrate that flooding cannot occur. Accordingly, historical flood information has been considered in conjunction with the available flood mapping, site topography, watercourse survey and site-specific hydrological and hydraulic assessment presented later in this report. 5.2 Historical OSI Maps Available historical 6-inch Ordnance Survey mapping dating from approximately 1830–1840 and 25-inch mapping dating from approximately 1900–1910 have been reviewed. The historical mapping indicates that the proposed development site was undeveloped and formed part of the surrounding agricultural lands. No mapped features or annotations indicative of historical flooding have been identified within the proposed development site on the historical mapping reviewed. The historical mapping has therefore not identified evidence of a documented historical flood mechanism affecting the proposed development area. This information has been considered alongside the other flood-risk information assessed in this report. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 18 Figure 9: Historical OSI Maps Historic 6 Inch Mapping Historic 25 Inch Mapping 5.3 OPW National Flood Hazard Mapping The available Office of Public Works (OPW) Historic Flood Event Mapping for Coolmuckbane, Co. Monaghan and the surrounding area have been reviewed as part of this Site-Specific Flood Risk Assessment. The OPW historical flood information identifies recorded flood events based on available documented sources and provides an indication of locations where flooding has previously been reported. A review of the available mapping identified no recorded historic flood event within the proposed development site. The available historical flood information has also been reviewed for the surrounding area to identify any evidence of a wider flood mechanism that may be relevant to the Site. The results of the review are presented in Figure 10 and have been considered together with the site topography, surveyed watercourse information and site-specific hydrological and hydraulic assessment presented later in this report. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 19 Figure 10: OPW Historic Flood Event Mapping – Coolmuckbane, Co. Monaghan A review of the OPW Historic Flood Event Mapping indicates that there are no recorded historic flood events within the application site. While flood records exist elsewhere within the wider catchment, there is no evidence of historical flooding affecting the proposed development site. 5.4 OPW Flood Mapping A review of the OPW Historic Flood Event Mapping indicates that there are no recorded historic flood events within the application site. While historic flood events are recorded elsewhere within the wider catchment, the available OPW records do not identify any documented historical flooding affecting the proposed development site. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 20 Figure 11: My Plan OPW Flood Map 5.5 CFRAM Fluvial Flood Risk Map The application site at Coolmuckbane, Co. Monaghan has been reviewed against the available Office of Public Works (OPW) Flood Maps and Catchment Flood Risk Assessment and Management (CFRAM) mapping. No detailed CFRAM hydraulic model or CFRAM-derived site-specific flood levels are available for the Drumrutagh Stream in the vicinity of the application site. Consequently, the available CFRAM mapping cannot, in isolation, be relied upon to establish the site-specific fluvial flood risk associated with this watercourse. To address this limitation, and in response to the flood-risk matters raised by Monaghan County Council, this Site-Specific Flood Risk Assessment has considered the following information: • available Office of Public Works (OPW) flood mapping; • Preliminary Flood Risk Assessment (PFRA) mapping; • available historical flood-event information; • aerial photography; • the submitted site layout and spot levels; • site walkover observations; • local topography and drainage characteristics; and • a site-specific hydrological and hydraulic assessment of the Drumrutagh Stream using surveyed watercourse cross- sections. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 21 Particular consideration has been given to the potential for fluvial flooding associated with the Drumrutagh Stream to affect the proposed dwelling, wastewater treatment and disposal infrastructure and associated site-development works. The assessment also considers the potential for the proposed development to displace floodwaters, obstruct flood-flow paths or increase flood risk elsewhere. The results of the site-specific hydrological and hydraulic assessment are presented in Section 6 and have been used to estimate representative design water levels for the 1% AEP, 1% AEP plus climate-change allowance and 0.1% AEP fluvial flood events. The findings of the site-specific assessment have subsequently been used to determine the applicable Flood Zone and assess the suitability of the proposed development in accordance with The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009). 5.5.1 Climate Change The potential effects of climate change have been considered in accordance with the precautionary approach advocated in The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009). As part of the site-specific hydrological assessment, a 20% climate-change allowance has been applied to the estimated 1% AEP design flow to provide a climate-change sensitivity scenario. The resulting design flow has been incorporated into the hydraulic assessment presented in Section 6. The assessment considers the predicted water level associated with the climate-change scenario relative to the surveyed watercourse cross-sections and adjoining bank levels, together with the location and levels of the proposed dwelling and wastewater treatment infrastructure. The assessment also considers whether the climate-change scenario could result in floodwater extending beyond the existing watercourse corridor, affect the proposed development, displace floodwaters, obstruct existing flood-flow paths or increase flood risk on adjoining or downstream lands. The results of this assessment are presented in Section 6 and have been taken into account in determining the applicable Flood Zone, residual flood risk and overall suitability of the proposed development from a flood-risk perspective. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 22 6.0 LEVEL 3 – DETAILED FLOOD RISK ASSESSMENT 6.1 Hydraulic Assessment Due to the indicative nature and associated uncertainty of the available Preliminary Flood Risk Assessment (PFRA) and Monaghan County Council flood-extent mapping, together with the absence of site-specific CFRAM-derived flood levels for the Drumrutagh Stream in the vicinity of the proposed development, a site-specific hydrological and hydraulic assessment has been undertaken. The assessment has been prepared using the best available hydrological, topographical and site-survey information available at the time of assessment. The design water levels presented in this report are predicted levels derived from the site -specific hydraulic assessment and are dependent on the adopted hydrological inputs, surveyed watercourse geometry, hydraulic parameters and assessment assumptions. The hydrology of the Drumrutagh Stream was initially assessed to establish representative design flood flows for use in the hydraulic assessment. The relevant OPW Flood Studies Update (FSU) node, 03_299_2, has an upstream catchment area of approximately 1.242 km². The FSU node is located approximately 260 m from the application site and has been used to obtain representative catchment descriptors for the Drumrutagh Stream in the vicinity of the proposed development. The proximity of the FSU node to the application site, together with its location on the relevant drainage network, provides an appropriate basis for the estimation of representative design flows for the site-specific assessment. The adopted catchment descriptors and resulting design flows are presented in the following sections. Figure 12: Location of OPW FSU Node 03_299_2 relative to the Application Site RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 23 6.1.1 Hydrological Assessment and Design Flows Given the relatively small size of the upstream catchment, a number of recognised hydrological estimation methodologies were reviewed, with particular consideration given to their applicability to a small, ungauged rural catchment. The principal methodologies considered were: • FSU 4.2a Small Catchments Equation; • FSU 7-Variable Equation; • FSU 3-Variable Equation; • Flood Studies Report (FSR) methodology; and • IH124 methodology. The detailed hydrological calculations and comparison of the methodologies considered are provided in Appendix A. The OPW Flood Studies Update methodology recommends the use of the FSU 4.2a Small Catchments Equation for catchments with an area of less than 25 km². As the catchment upstream of the relevant FSU node has an area of approximately 1.242 km², the FSU 4.2a Small Catchments Equation has been adopted as the principal methodology for estimation of design flood flows. The principal catchment descriptors adopted in the FSU 4.2a assessment are summarised in Table 7. Table 7: Adopted Catchment Descriptors Catchment Descriptor Adopted Value Catchment Area (AREA) 1.242 km² Standard Average Annual Rainfall (SAAR) 937.1 mm Base Flow Index (BFI) 0.712 Flood Attenuation by Reservoirs and Lakes (FARL) 1.000 Main Channel Slope (S1085) 3.520 m/km Application of the FSU 4.2a Small Catchments Equation gives an estimated median annual flood (QMED) of approximately 0.283 m³/s. The corresponding mean annual flood (QBAR) adopted for application of the relevant growth factors is approximately 0.303 m³/s. The adopted growth factors were subsequently applied to QBAR to derive the design flows for the required return periods. The resulting design flows are summarised in Table 8. Table 8: Adopted River Design Flows Event Growth Factor Adopted Flow (m³/s) QMED – 0.283 QBAR 1.000 0.303 1% AEP / Q100 2.610 0.790 1% AEP + 20% climate-change allowance – 0.949 0.1% AEP / Q1000 3.654 1.107 A 20% climate-change allowance has been applied to the adopted 1% AEP design flow, increasing the design flow from approximately 0.790 m³/s to 0.949 m³/s. For comparison and as a sensitivity check on the adopted hydrological methodology, the FSU 7-Variable Equation was also reviewed. This methodology produces lower estimated design flows for the subject catchment, as summarised in Table 9. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 24 Table 9: Comparison of Hydrological Estimation Methods Method QMED (m³/s) QBAR (m³/s) Q100 / 1% AEP (m³/s) Q100 + 20% (m³/s) Q1000 / 0.1% AEP (m³/s) FSU 4.2a Small Catchments 0.283 0.303 0.790 0.949 1.107 FSU 7-Variable 0.110 0.117 0.306 0.367 0.429 The FSU 4.2a Small Catchments Equation produces substantially higher design flows than the FSU 7-Variable Equation. Having regard to the small catchment area and the specific applicability of the FSU 4.2a methodology to small catchments, the FSU 4.2a design flows have been adopted as the conservative basis for the hydraulic assessment. Accordingly, the following principal design events have been assessed: • 1% AEP (Q100): 0.790 m³/s; • 1% AEP + 20% climate-change allowance: 0.949 m³/s; and • 0.1% AEP (Q1000): 1.107 m³/s. Figure 13: Cross Section Locations RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 25 Figure 14: Section 1, 1 in 100-year & 1 in 1000-year Flood Levels RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 26 RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 27 RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 28 RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 29 RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 30 6.1.2 Hydraulic Assessment A site-specific hydraulic assessment was undertaken using the surveyed watercourse cross-sections in the vicinity of the proposed development, including Sections 1 and 2 adjacent to the Site, together with additional downstream cross-sections. The surveyed cross-sections provide site-specific information on the existing channel geometry, channel-bed levels, bank levels and adjoining ground levels and have been used to assess the hydraulic capacity of the Drumrutagh Stream under the adopted design-flow scenarios. Appropriate Manning's roughness coefficients have been assigned to the watercourse channel and adjoining overbank areas having regard to the surveyed channel characteristics, vegetation and land cover. Conservative hydraulic parameters have been adopted where uncertainty exists. The hydraulic assessment has been undertaken for the 1% AEP, 1% AEP plus 20% climate-change allowance and 0.1% AEP design events. The predicted design water levels have been compared with the surveyed channel and bank levels to determine the potential for out-of-bank flooding and the relationship between the predicted flood levels and the proposed development. The assessment has also considered the potential influence of downstream hydraulic structures and the sensitivity of predicted water levels to partial blockage of the downstream culvert, thereby providing an assessment of residual flood risk associated with a reduced hydraulic capacity at this structure. The resulting design water levels are presented in the following section and have been used to determine the potential extent of fluvial flood risk to the proposed dwelling, wastewater treatment and disposal infrastructure and associated site- development works. The site-specific hydraulic assessment was undertaken using the adopted design flows summarised below. Design Event Adopted Flow 1% AEP / Q100 0.790 m³/s 1% AEP +20% MRFS 0.949 m³/s 0.1% AEP / Q1000 1.107 m³/s A total of 10 surveyed cross-sections (XS01–XS10) were assessed along the Drumrutagh Stream. The surveyed river-bed levels decrease from approximately 51.706 mOD at XS01 to 48.152 mOD at XS10, confirming a general downstream fall through the surveyed reach. For each design event, the water level within each surveyed cross-section was iteratively increased until the calculated conveyance, using Manning's equation, corresponded with the applicable design flow. The resulting predicted design water levels are presented in Table 10. Table 10: Predicted Design Water Levels at Surveyed Cross-Sections Section River Bed Level (mOD) 1% AEP Q100 (mOD) 1% AEP +20% MRFS (mOD) 0.1% AEP Q1000 (mOD) XS01 51.706 52.208 52.261 52.310 XS02 51.553 52.056 52.103 52.145 XS03 51.304 51.812 51.857 51.898 XS04 51.038 51.502 51.555 51.604 XS05 50.749 51.278 51.330 51.377 XS06 50.537 51.084 51.140 51.192 XS07 50.436 50.966 51.018 51.066 XS08 50.117 50.716 50.771 50.821 XS09 48.407 48.894 48.939 48.981 XS10 48.152 48.557 48.596 48.631 RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 31 The predicted design water levels generally decrease in the downstream direction, consistent with the surveyed fall in channel- bed elevation. The results have been compared with the surveyed bank levels at the individual cross -sections to determine the potential for out-of-bank flooding. Particular consideration has been given to XS06, which is representative of the watercourse in the vicinity of the proposed development. 6.1.2 Culvert Blockage Sensitivity Assessment An existing culvert is located on the Drumrutagh Stream between surveyed cross-sections XS08 and XS09, downstream of the proposed development. The proposed development is located approximately adjacent to XS06. Partial blockage of the downstream culvert has the potential to restrict conveyance and increase upstream water levels. A blockage sensitivity assessment has therefore been undertaken to consider the potential residual flood risk associated with a substantial reduction in culvert capacity. Detailed survey information for the culvert, including its dimensions, invert levels, soffit level and barrel length, was not available at the time of assessment. Accordingly, a detailed culvert inlet/outlet control calculation and precise prediction of blockage- related headwater levels could not be undertaken. For the purposes of this SSFRA, a 66% blockage sensitivity scenario has therefore been assessed, representing a substantial reduction in the assumed effective conveyance of the downstream structure. This assessment is intended as a conservative sensitivity test rather than a detailed hydraulic model of the culvert. Table 11: Adopted Design Flows for Culvert Blockage Sensitivity Assessment Design Event Adopted Flow (m³/s) 1% AEP (Q100) 0.790 1% AEP + 20% MRFS 0.949 0.1% AEP (Q1000) 1.107 Blockage Sensitivity Methodology The effect of the assumed restriction has been assessed at XS08, immediately upstream of the identified culvert location. For conservative screening purposes, the full calculated increase in water level at XS08 has subsequently been applied to the corresponding predicted water level at XS06, representative of the watercourse in the vicinity of the proposed development. This represents a conservative screening assumption because it does not allow for attenuation or reduction in the blockage- related water-level increase with distance upstream of the hydraulic control. Table 12: 66% Culvert Blockage Sensitivity Results Design Event Unblocked Level at XS08 (mOD) 66% Blockage Screening Level at XS08 (mOD) Estimated Increase (m) 1% AEP (Q100) 50.716 51.117 +0.401 1% AEP +20% MRFS 50.771 51.207 +0.436 0.1% AEP (Q1000) 50.821 51.288 +0.467 The sensitivity assessment indicates a potential increase in water level immediately upstream of the culvert ranging from approximately 0.40 m to 0.47 m, with the greatest increase associated with the 0.1% AEP event. For conservative assessment of the proposed development, these increases have been applied in full to the corresponding predicted water levels at XS06. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 32 Table 13: Conservative Blockage Sensitivity at Development Location (XS06) Design Event Unblocked XS06 Level (mOD) Blockage Allowance (m) Conservative Screening Level at XS06 (mOD) Lower Bank Level at XS06 (mOD) Remaining Bank Freeboard (m) 1% AEP (Q100) 51.084 +0.401 51.485 52.320 0.835 1% AEP +20% MRFS 51.140 +0.436 51.576 52.320 0.744 0.1% AEP (Q1000) 51.192 +0.467 51.659 52.320 0.661 The sensitivity assessment indicates that even under the assumed 66% partial blockage scenario, the conservative screening water levels at XS06 remain below the lower surveyed bank level. For the 1% AEP plus 20% climate-change allowance, the conservative screening level at XS06 is approximately 51.576 mOD, providing approximately 0.744 m freeboard to the lower surveyed bank level of 52.320 mOD. For the more extreme 0.1% AEP event, the conservative screening level is approximately 51.659 mOD, providing approximately 0.661 m freeboard to the lower surveyed bank level. Accordingly, the sensitivity assessment indicates that the assumed 66% partial blockage of the downstream culvert would not result in overtopping of the surveyed watercourse bank at XS06. On the basis of this conservative screening assessment, blockage-related floodwaters are not predicted to extend from the watercourse towards the proposed dwelling, wastewater treatment infrastructure or principal development area. Partial blockage of the downstream culvert is therefore not considered to represent an unacceptable residual fluvial flood ri sk to the proposed development under the scenarios assessed. 6.2 Discussion of Findings The site-specific hydraulic assessment has considered the capacity of the surveyed Drumrutagh Stream cross-sections under the following design events: • 1% AEP (Q100): 0.790 m³/s; • 1% AEP + 20% climate-change allowance: 0.949 m³/s; and • 0.1% AEP (Q1000): 1.107 m³/s. The assessment has been undertaken using the surveyed cross-section geometry and the adopted hydraulic parameters, including a Manning's roughness coefficient of 0.040 and hydraulic gradient of 0.005 (1:200). At XS01, the predicted design water levels are approximately 52.208 mOD, 52.261 mOD and 52.310 mOD for the 1% AEP, 1% AEP plus 20% climate-change allowance and 0.1% AEP events respectively. The lower surveyed bank level at XS01 is approximately 52.341 mOD. The predicted 0.1% AEP water level of 52.310 mOD therefore remains below the lower bank level, although with a relatively limited freeboard of approximately 0.031 m. At XS02, the lower surveyed bank level is approximately 52.519 mOD, compared with a predicted 0.1% AEP water level of approximately 52.145 mOD, providing approximately 0.374 m freeboard. Particular consideration has been given to XS06, representative of the watercourse in the vicinity of the proposed development. The predicted unblocked water levels at XS06 are 51.084 mOD, 51.140 mOD and 51.192 mOD for the respective design events, compared with a lower surveyed bank level of 52.320 mOD. This provides approximately 1.236 m freeboard for the 1% AEP event, 1.180 m for the climate-change scenario and 1.128 m for the 0.1% AEP event under the unblocked condition. The additional culvert blockage sensitivity assessment indicates that, even where the full calculated blockage-related increase at XS08 is conservatively transferred upstream to XS06, approximately 0.661 m of bank freeboard remains during the 0.1% AEP event. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 33 The assessment therefore indicates that the principal design events are contained within the surveyed watercourse corridor in the vicinity of the proposed development, including under the conservative culvert blockage sensitivity scenario. Table 14: Representative Hydraulic Results Parameter XS01 XS02 XS06 – Development Area River bed level 51.706 mOD 51.553 mOD 50.537 mOD Lower bank-top level 52.341 mOD 52.519 mOD 52.320 mO Q100 water level 52.208 mOD 52.056 mOD 51.084 mOD Q100 bank freeboard 0.133m 0.463m 1.236 m Q100 +20% CC water level 52.261 mOD 52.103 mOD 51.140 mOD Q100 +20% CC bank freeboard 0.080 m 0.416 m 1.180 m Q1000 water level 52.310 mOD 52.145 mOD 51.192 mOD Q1000 bank freeboard 0.031 m 0.374 m 1.128 m The hydraulic assessment indicates that the adopted design flows can be accommodated within the surveyed watercourse corridor in the vicinity of the proposed development. At XS06, which is representative of the development area, the predicted water levels remain below the lower surveyed bank level for each of the assessed design events, with approximately 1.180 m of bank freeboard remaining during the 1% AEP plus 20% climate-change event and 1.128 m during the 0.1% AEP event. The 0.1% AEP event represents the highest predicted water level of the events assessed, with calculated design water levels ranging from approximately 52.310 mOD at XS01 to 48.631 mOD at XS10. While the predicted 0.1% AEP water level at XS01 is close to the lower surveyed bank level, remaining approximately 0.031 m below bank level, substantially greater freeboard is maintained in the vicinity of the proposed development at XS06. 6.3 Proposed Finished Floor Level The proposed dwelling has a Finished Floor Level (FFL) of +100.000 m relative to the local datum adopted on the submitted planning drawings. Existing spot levels in the vicinity of the proposed dwelling are generally close to this level and indica te that the proposed development is located on relatively level ground. The site-specific hydraulic assessment predicts fluvial design water levels in Ordnance Datum (mOD). At XS06, which is representative of the watercourse in the vicinity of the proposed development, the predicted water levels are approximately 51.084 mOD for the 1% AEP event, 51.140 mOD for the 1% AEP plus 20% climate-change event and 51.192 mOD for the 0.1% AEP event. These predicted levels remain below the lower surveyed bank level of approximately 52.320 mOD at XS06, providing approximately 1.236 m, 1.180 m and 1.128 m of bank freeboard, respectively. The submitted planning drawings use a separate local datum for the proposed development levels and a surveyed conversion between this local datum and Ordnance Datum has not been established within the information available for this assessment. Accordingly, a direct numerical comparison between the proposed dwelling FFL of +100.000 m and the predicted watercourse levels in mOD has not been made. However, such a comparison is not necessary to establish the fluvial flood risk to the proposed dwelling. The hydraulic assessment demonstrates that the assessed design flows remain within the surveyed watercourse banks in the vicinity of the proposed development, including during the 0.1% AEP event. The additional culvert blockage sensitivity assessment similarly indicates that the conservative screening level at XS06 remains below the lower surveyed bank level. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 34 Accordingly, the assessed fluvial floodwaters are not predicted to leave the watercourse corridor in the vicinity of the proposed development or extend towards the proposed dwelling. The proposed dwelling is therefore considered to be located outside the predicted fluvial flood extent, and the proposed Finished Floor Level is considered appropriate from a fluvial flood-risk perspective. 6.4 Access and Egress Vehicular access to the proposed development is provided from the L1402 Local Primary Road along the northern boundary of the site. The proposed access is therefore located on the opposite side of the development site from the Drumrutagh Stream, which is situated to the south. The site-specific hydraulic assessment indicates that the predicted water levels associated with the 1% AEP, 1% AEP plus 20% climate-change allowance and 0.1% AEP events remain below the surveyed watercourse bank levels in the vicinity of the proposed development. At XS06, representative of the development area, the predicted 0.1% AEP water level remains approximately 1.128 m below the lower surveyed bank level. The additional culvert blockage sensitivity assessment also indicates that, under the conservative 66% partial blockage scenario, the predicted screening water level at XS06 remains approximately 0.661 m below the lower surveyed bank level during the 0.1% AEP event. Accordingly, the assessed fluvial floodwaters are not predicted to leave the watercourse corridor in the vicinity of the proposed development or establish a flood pathway through the development site towards the L1402 Local Primary Road. On the basis of the site-specific hydraulic assessment, safe access to and egress from the proposed development via the L1402 is not expected to be adversely affected by fluvial flooding from the Drumrutagh Stream during the assessed design events. No unacceptable residual fluvial flood risk associated with the proposed access and egress arrangements has therefore been identified. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 35 7.0 Assessment of Flooding Mechanisms 7.1 Preamble The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009) seek to avoid inappropriate development within areas at risk of flooding and to ensure that new development does not increase flood risk elsewhere. This Site-Specific Flood Risk Assessment has been prepared in response to the Further Information request issued by Monaghan County Council. The assessment considers the potential sources and mechanisms of flooding that could affect the proposed development at Coolmuckbane, Co. Monaghan and evaluates the suitability of the site for the proposed residential development, including the proposed dwelling, wastewater treatment and disposal infrastructure, surface-water drainage and site access. 7.2 Initial Assessment The potential flooding mechanisms relevant to the proposed development have been screened having regard to the background information review, site-specific investigations, available flood mapping, site topography, drainage characteristics and the detailed hydrological and hydraulic assessment presented in Section 6 Table 15: Assessment of Potential Flooding Mechanisms Source/Pathway Significant Comment/Reason Fluvial Flooding Drumrutagh Stream Yes – Assessed The Drumrutagh Stream is located to the south of the Site. A site- specific hydrological and hydraulic assessment has been undertaken. At XS06, representative of the development area, the assessed 1% AEP, 1% AEP plus 20% climate-change and 0.1% AEP water levels remain below the lower surveyed bank level. Structure Blockage Yes – assessed An existing culvert is located downstream between XS08 and XS09. A conservative 66% blockage sensitivity assessment indicates that the 0.1% AEP screening level at XS06 remains approximately 0.661 m below the lower surveyed bank level. Flood Defence Failure N/A No formal flood-defence infrastructure has been identified in the vicinity of the proposed development. Coastal Flooding Tidal/Coastal N/A The Site is inland and is not affected by tidal or coastal flooding. Other Sources Pluvial Flooding No – Low Risk No significant existing pluvial flooding mechanism has been identified within the proposed development area. Surface-water runoff generated from the proposed dwelling, hardstanding and entrance will be collected and discharged to an engineered soakaway system designed in accordance with BRE Digest 365. The drainage system will therefore provide dedicated management of surface-water runoff generated by the development. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 36 Groundwater Flooding No – Low Risk Groundwater was encountered at approximately 1.80 m below ground level during the EPA Site Characterisation Assessment. No groundwater emergence, persistent waterlogging or surface-water ponding was identified at ground level. Drainage/Infrastructure Failure No – Low Risk No significant existing drainage or infrastructure-failure mechanism has been identified. Proposed surface-water runoff will be managed by the dedicated soakaway system. Infrastructure failure No – Low Risk No significant existing drainage or infrastructure-failure mechanism has been identified. Proposed surface-water runoff will be managed by the dedicated soakaway system. Rainfall Ponding/Overland Flow No – Low Risk No significant rainfall ponding or defined overland-flow pathway affecting the proposed development has been identified from the available site information and observations. Reservoirs/Canals/Artificial Sources N/A No reservoir, canal or other significant artificial water-retaining feature has been identified in proximity to, or hydraulically connected with, the Site. 7.3 Flood Mechanisms Flooding may arise from a number of different sources, including rivers and streams (fluvial flooding), intense rainfall and overland flow (pluvial flooding), groundwater emergence, drainage or infrastructure failure and artificial sources. Each potential flooding mechanism relevant to the proposed development has been considered as part of this assessment. 7.3.1 Fluvial Flooding Fluvial flooding occurs when the flow within a river or stream exceeds the available channel capacity, resulting in water overtopping the channel banks and inundating adjoining lands. The Drumrutagh Stream, located to the south of the application site, represents the principal potential source of fluvial flo od risk to the proposed development. In response to the concerns raised by Monaghan County Council, a site-specific hydrological and hydraulic assessment of the watercourse has been undertaken using surveyed river cross-sections and the adopted FSU 4.2a design flows. The assessment considered the 1% AEP event at 0.790 m³/s, the 1% AEP plus 20% climate -change event at 0.949 m³/s and the 0.1% AEP event at 1.107 m³/s. At XS06, representative of the watercourse in the vicinity of the proposed development, the predicted water levels are approximately 51.084 mOD, 51.140 mOD and 51.192 mOD for the respective design events. These levels remain below the lower surveyed bank level of approximately 52.320 mOD, providing bank freeboards of approximately 1.236 m, 1.180 m and 1.128 m, respectively. A conservative sensitivity assessment was also undertaken for an assumed 66% partial blockage of the downstream culvert between XS08 and XS09. Under this scenario, the conservative 0.1% AEP screening level at XS06 is approximately 51.659 mOD, remaining approximately 0.661 m below the lower surveyed bank level. The assessment therefore indicates that the assessed fluvial design events remain within the surveyed watercourse corridor in the vicinity of the proposed development, including under the conservative culvert blockage sensitivity scenario. Accordingly, fluvial floodwaters from the Drumrutagh Stream are not predicted to extend towards the proposed dwelling, wastewater treatment infrastructure or principal development area under the assessed design scenarios. The proposed RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 37 development is therefore considered to be at low residual risk from fluvial flooding and is not expected to increase fluvial flood risk elsewhere or obstruct an existing flood-flow pathway. 7.3.2 Pluvial flooding: Pluvial flooding may occur where intense rainfall generates surface-water runoff at a rate greater than the infiltration capacity of the ground or the capacity of the local drainage system. No evidence of significant surface-water ponding was observed within the proposed development area during the site inspections undertaken for either this Flood Risk Assessment or the separate EPA Site Characterisation Assessment. Surface-water runoff generated from the proposed roof areas, hardstanding and site entrance will be collected through a dedicated drainage system and discharged to an engineered soakaway. The soakaway assessment has been undertaken in accordance with BRE Digest 365, using a tested infiltration rate of approximately 0.0997 mm/s. The assessment provides for an impermeable contributing area of approximately 638 m² and a proposed soakaway measuring approximately 13 m long × 1 m wide × 1.2 m effective depth. The calculated available soakaway storage exceeds the maximum required storage identified within the drainage design assessment. The proposed surface-water drainage arrangement is therefore considered adequate to manage runoff generated by the development without causing a significant increase in flood risk to adjoining lands. Residual pluvial flood risk is therefore considered low. 7.3.3 Groundwater flooding: Groundwater flooding occurs where groundwater levels rise sufficiently to emerge at or above ground level, generally following prolonged periods of rainfall. A separate EPA Site Characterisation and Site Suitability Assessment was undertaken for the proposed wastewater treatment and disposal system. Groundwater was encountered within the trial hole at approximately 1.80 m below ground level. Although groundwater is present beneath the Site, no evidence of groundwater emergence, persistent waterlogging or surface-water ponding was identified within the proposed development or wastewater-treatment area during the site investigations. The proposed wastewater disposal system has been designed to maintain a minimum of 0.90 m of suitable unsaturated percolating material between the base of the lowest part of the gravel distribution bed and groundwater. Having regard to the depth at which groundwater was encountered, the absence of groundwater emergence at ground level and the proposed wastewater-system design, groundwater flooding is considered to present a low risk to the proposed development. 7.3.4 Tidal/Coastal Flooding The application site is located within an inland rural area of County Monaghan and is not hydraulically connected to a tidal or coastal waterbody. Accordingly, the risk of tidal or coastal flooding is considered negligible. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 38 8.0 JUSTIFICATION TEST The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009) classify land into three flood zones based on the probability of fluvial and coastal flooding: • Flood Zone A – high probability of flooding; • Flood Zone B – moderate probability of flooding; and • Flood Zone C – low probability of flooding, comprising lands outside Flood Zones A and B. The Guidelines also classify development according to its vulnerability to flooding. Dwelling houses are classified as Highly Vulnerable Development. Highly Vulnerable Development is considered appropriate within Flood Zone C, whereas development of this type within Flood Zones A or B would generally require application of the Development Management Justification Test. 8.1 Flood Zone Classification of the Proposed Development The site-specific hydrological and hydraulic assessment undertaken for the Drumrutagh Stream has considered the 1% AEP, 1% AEP plus 20% climate-change allowance and 0.1% AEP fluvial design events. At XS06, representative of the watercourse in the vicinity of the proposed development, the predicted design water levels remain below the lower surveyed bank level for all assessed events. The predicted 0.1% AEP water level is approximately 51.192 mOD, compared with a lower surveyed bank level of approximately 52.320 mOD, providing approximately 1.128 m of bank freeboard. A conservative sensitivity assessment has also been undertaken for an assumed 66% partial blockage of the downstream culvert. Under this scenario, the conservative 0.1% AEP screening level at XS06 is approximately 51.659 mOD, remaining approximately 0.661 m below the lower surveyed bank level. The assessment therefore indicates that the 0.1% AEP fluvial event remains within the surveyed watercourse corridor in the vicinity of the proposed development, including under the conservative culvert blockage sensitivity scenario. Floodwaters associated with the assessed events are not predicted to extend towards the proposed dwelling, wastewater treatment infrastructure or principal development area. Accordingly, the proposed residential development area is considered to be located within Flood Zone C. 8.2 Development Vulnerability and Justification Test The proposed development comprises a one-off residential dwelling and is therefore classified as Highly Vulnerable Development in accordance with the Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009). Ancillary elements of the development, including the domestic garage, wastewater treatment and disposal infrastructure, access and associated site works, form part of the overall residential development. Highly Vulnerable Development is considered appropriate within Flood Zone C under the Guidelines. Accordingly, having regard to the findings of this Site-Specific Flood Risk Assessment and the classification of the proposed development area as Flood Zone C, the proposed development is considered appropriate from a fluvial flood-risk perspective and application of the Development Management Justification Test is not required. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 39 9.0 DESIGN FLOOD LEVELS The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009) require flood risk to be assessed having regard to the nature and vulnerability of the proposed development and the available site-specific flood risk information. A site-specific hydrological and hydraulic assessment has been undertaken for the Drumrutagh Stream using design flows derived from the FSU 4.2a Small Catchments methodology and surveyed watercourse cross-sections in the vicinity of the proposed development. The assessment considered the 1% AEP, 1% AEP plus 20% climate-change allowance and 0.1% AEP fluvial events. At XS06, representative of the watercourse in the vicinity of the proposed development, the predicted design water levels are: • 1% AEP: 51.084 mOD; • 1% AEP + 20% climate-change allowance: 51.140 mOD; and • 0.1% AEP: 51.192 mOD. The lower surveyed bank level at XS06 is approximately 52.320 mOD. The predicted design water levels therefore provide approximately 1.236 m, 1.180 m and 1.128 m of bank freeboard, respectively. A conservative sensitivity assessment has also been undertaken for an assumed 66% partial blockage of the downstream culvert. Under the 0.1% AEP event, the resulting conservative screening level at XS06 is approximately 51.659 mOD, remaining approximately 0.661 m below the lower surveyed bank level. The hydraulic assessment therefore indicates that the assessed design events remain within the surveyed watercourse corridor in the vicinity of the proposed development, including under the conservative culvert blockage sensitivity scenario. The proposed dwelling has a Finished Floor Level of +100.000 m relative to the local datum adopted on the submitted planning drawings. As a surveyed conversion between this local datum and Ordnance Datum has not been established, a direct numerical comparison between the proposed dwelling FFL and the predicted watercourse levels in mOD has not been made. Notwithstanding this, the hydraulic assessment demonstrates that the assessed fluvial floodwaters remain within the surveyed watercourse banks in the vicinity of the proposed development and are not predicted to extend towards the proposed dwelling, wastewater treatment infrastructure or principal development area. Accordingly, the proposed development is considered to be at low risk from fluvial flooding under the assessed design scenarios. 9.1 Potential for the Development to Contribute to Off-Site Flooding The proposed development has been assessed to determine whether it could increase flood risk to adjoining or downstream lands. The site-specific hydraulic assessment indicates that the assessed fluvial design events remain within the surveyed watercourse corridor and below the surveyed bank levels in the vicinity of the proposed development. The proposed dwelling, wastewater treatment infrastructure and associated site works are therefore located outside the area required for conveyance of the assessed fluvial flood events. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 40 The development does not involve the culverting, diversion or obstruction of the Drumrutagh Stream and no development works are proposed within the active watercourse corridor. The proposal will therefore not materially reduce available fluvial flood storage or obstruct an existing fluvial flow path. Surface-water runoff from the proposed dwelling, hardstanding and site entrance will be collected and discharged to an engineered soakaway designed in accordance with BRE Digest 365. The soakaway will manage runoff generated by the proposed impermeable areas and avoid direct uncontrolled discharge of development runoff to adjoining lands or the Drumrutagh Stream. Accordingly, the proposed development is not expected to displace floodwaters, materially increase surface-water runoff to adjoining lands or increase fluvial flood risk within the immediate vicinity or downstream catchment. 9.2 Residual Flood Risk Residual flood risk is the risk that remains after appropriate flood avoidance, design and mitigation measures have been incorporated into a development. The principal residual risks considered in respect of the proposed development comprise: • an extreme fluvial event exceeding the assessed design conditions; • partial blockage of the downstream culvert; • exceptional pluvial rainfall and exceedance or blockage of the proposed surface-water drainage system; and • elevated groundwater levels. A conservative 66% partial culvert blockage sensitivity assessment has been undertaken. Under the 0.1% AEP event, including the conservative blockage allowance, the predicted screening water level at XS06 remains approximately 0.661 m below the lower surveyed watercourse bank level. The separate EPA Site Characterisation Assessment recorded groundwater at approximately 1.80 m below ground level and identified no groundwater emergence, persistent waterlogging or surface-water ponding within the proposed wastewater treatment area. The proposed wastewater disposal system will maintain the required unsaturated separation to groundwater. Surface-water runoff generated by the proposed development will be managed through a dedicated engineered soakaway designed in accordance with BRE Digest 365. The proposed development does not obstruct an identified flood-flow path, reduce the assessed fluvial flood-storage area or involve works within the Drumrutagh Stream corridor. Having regard to the site-specific hydrological and hydraulic assessment, culvert blockage sensitivity assessment, proposed surface-water drainage measures and site-specific groundwater information, the residual flood risk associated with the proposed development is considered low and capable of being appropriately managed. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 41 Table 18: Residual Flood Risk Assessment Description of Risk Hazard Residual Impact Fluvial flooding from the Drumrutagh Stream Extreme event exceeding assessed design conditions The 0.1% AEP water level at XS06 remains approximately 1.128 m below the lower surveyed bank level. Residual risk is considered Low. Downstream culvert blockage Reduced downstream conveyance and increased upstream water level Under the conservative 66% blockage sensitivity scenario, the 0.1% AEP screening level at XS06 remains approximately 0.661 m below the lower surveyed bank level. Residual risk is considered Low. Climate change Increase in design flood magnitude A 20% climate-change allowance has been applied to the 1% AEP design flow. The resulting predicted level at XS06 remains approximately 1.180 m below the lower surveyed bank level. Residual risk is considered Low. Access and egress Fluvial flooding affecting access to the L1402 The assessed fluvial events remain within the watercourse corridor in the vicinity of the development and are not predicted to establish a flood pathway through the Site towards the L1402. Residual risk is considered Low. Surface-water drainage Blockage or exceedance of the proposed soakaway Surface-water runoff will be managed by an engineered soakaway designed in accordance with BRE Digest 365. Residual pluvial flood risk is considered Low. Groundwater Elevated groundwater levels Groundwater was encountered at approximately 1.80 m below ground level, with no groundwater emergence or persistent surface- water ponding identified. Residual groundwater flood risk is considered Low. Wastewater treatment and disposal system Fluvial flooding, groundwater or surface- water inundation affecting system performance The site assessment identified suitable conditions for the proposed wastewater treatment and disposal arrangement, subject to maintenance of the required unsaturated separation to groundwater. The hydraulic assessment indicates that assessed fluvial floodwaters do not extend to the development area. Residual risk is considered Low. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 42 10.0 CLIMATE CHANGE The potential effects of climate change have been considered in accordance with the precautionary approach advocated by The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009). As part of the site-specific hydraulic assessment, a 20% increase has been applied to the 1% AEP design flow to represent the Mid-Range Future Scenario (MRFS). This increases the adopted 1% AEP design flow from 0.790 m³/s to 0.949 m³/s. At XS06, representative of the watercourse in the vicinity of the proposed development, the predicted water level for the 1% AEP plus 20% MRFS climate-change event is approximately 51.140 mOD. The lower surveyed bank level at this location is approximately 52.320 mOD, providing approximately 1.180 m of bank freeboard under the assessed climate-change scenario. The hydraulic assessment therefore indicates that the 1% AEP plus 20% MRFS climate-change event remains contained within the surveyed watercourse corridor in the vicinity of the proposed development. The proposed dwelling and wastewater treatment infrastructure are located outside the predicted fluvial flood extent. Surface-water runoff generated by the proposed development will also be managed through an engineered soakaway designed in accordance with BRE Digest 365. Accordingly, the assessed climate-change scenario is not expected to result in an unacceptable increase in fluvial flood risk to the proposed dwelling, wastewater treatment infrastructure or site access and is not expected to increase flood risk elsewhere. 10.1 Assessing Flood Risk in the Context of Climate Change The assessment demonstrates that an allowance for the potential effects of climate change has been incorporated directly into the site-specific hydraulic assessment. The 1% AEP plus 20% MRFS event remains within the surveyed watercourse banks in the vicinity of the proposed development, with approximately 1.180 m of bank freeboard at XS06. In addition, the proposed development does not involve culverting, diversion or obstruction of the Drumrutagh Stream, and surface-water runoff generated by the development will be managed through the proposed engineered soakaway system. On the basis of the site-specific assessment undertaken, climate change is not expected to result in an unacceptable flood risk to the proposed development or cause a significant increase in flood risk elsewhere. RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 43 11.0 CONCLUSION This Site-Specific Flood Risk Assessment has been prepared in response to Item 4 of the Further Information request issued by Monaghan County Council in respect of Planning Reference 26/60030. The assessment has considered available OPW flood-risk information, historical flood information, site observations, local topography, the proposed site layout, surface-water drainage arrangements, the proposed wastewater treatment infrastructure and the proximity of the Drumrutagh Stream. A site-specific hydrological and hydraulic assessment of the Drumrutagh Stream has been undertaken using FSU catchment information and surveyed river cross-sections. The assessment considered the 1% AEP, 1% AEP plus 20% MRFS climate-change and 0.1% AEP fluvial flood events. The adopted FSU 4.2a Small Catchments methodology provides a 1% AEP design flow of approximately 0.790 m³/s, increasing to approximately 0.949 m³/s following application of the 20% MRFS climate-change allowance. The assessed 0.1% AEP flow is approximately 1.107 m³/s. The hydraulic assessment indicates that the predicted design flood levels remain below the surveyed watercourse bank levels in the vicinity of the proposed development. At XS06, representative of the watercourse in the vicinity of the proposed development, the predicted 1% AEP plus 20% MRFS water level is approximately 51.140 mOD, compared with a lower surveyed bank level of approximately 52.320 mOD, providing approximately 1.180 m of bank freeboard. The assessed fluvial flood events therefore remain within the watercourse corridor and do not extend towards the principal development area. A conservative sensitivity assessment has also been undertaken for a 66% partial blockage of the downstream culvert. Under the 0.1% AEP event with the conservative blockage allowance applied, the resulting screening level at XS06 remains approximately 0.66 m below the lower surveyed bank level. The assessed culvert blockage scenario is therefore not expected to result in floodwaters extending towards the proposed dwelling or wastewater treatment infrastructure. The proposed dwelling has a Finished Floor Level of +100.000 m relative to the local datum used on the submitted planning drawings. While a precise surveyed conversion between this local datum and Ordnance Datum has not been established, the available site topography, surveyed watercourse geometry and hydraulic assessment demonstrate that the proposed dwelling is situated on elevated ground above the predicted fluvial flood levels and outside the area affected by the assessed design events. The proposed wastewater treatment and disposal system has been subject to a separate Site Characterisation and Site Suitability Assessment undertaken in accordance with the EPA Code of Practice 2021. Groundwater was encountered at approximately 1.80 m below ground level, with no evidence of groundwater emergence or surface-water ponding identified within the proposed wastewater-treatment area. The site assessment concluded that the site is suitable for the proposed wastewater treatment and disposal system. The proposed system will comprise a Tricel P6 secondary treatment system, Ter3 Pod and associated gravel distribution bed/soil polishing filter, or equivalent appropriately certified system, and will maintain a minimum of 0.90 m of suitable unsaturated percolating material between the base of the lowest part of the gravel distribution bed and groundwater at all times. Surface-water runoff from the proposed dwelling, hardstanding and entrance will be collected and discharged to an engineered soakaway designed in accordance with BRE Digest 365. The soakaway assessment indicates that adequate storage capacity will be provided to manage runoff generated by the proposed development. On the basis of the assessment undertaken, the proposed development is considered to be located within Flood Zone C. The proposed dwelling constitutes Highly Vulnerable Development and is appropriate within Flood Zone C in accordance with The Planning System and Flood Risk Management – Guidelines for Planning Authorities (DoEHLG/OPW, 2009). A Development Management Justification Test is therefore not required. It is concluded that the proposed development: • will not be at unacceptable risk of fluvial flooding; RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 44 • will not result in the displacement of floodwaters off-site or exacerbate flooding within the immediate vicinity or wider area; • will not obstruct or impede important flood flow paths; • will not result in a material reduction in available fluvial flood storage; • will not give rise to residual flood risks that cannot be managed to an acceptable level; • will not adversely affect the proper functioning of the proposed wastewater treatment system as a consequence of fluvial flooding; • incorporates appropriate measures for the management of surface-water runoff; and • is considered suitable for the proposed location from a flood-risk perspective. Accordingly, the proposed development can be accommodated without giving rise to an unacceptable flood risk to the development itself, adjoining lands or downstream receptors and satisfactorily addresses the matters raised under Item 4 of the Further Information request issued by Monaghan County Council. Signed: Nevin Traynor BSc. Env, H. Dip I.T, Cert SHWW. For Traynor Environmental Ltd RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 45 SITE SPECIFIC FLOOD RISK ASSESSMENT COMPLETED BY TRAYNOR ENVIRONMENTAL LTD APPENDIX A – HYDROLOGICAL CALCULATIONS RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 46 RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment 47 SITE SPECIFIC FLOOD RISK ASSESSMENT COMPLETED BY TRAYNOR ENVIRONMENTAL LTD APPENDIX B – TOPOGRAPHICAL SURVEY RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment SITE SPECIFIC FLOOD RISK ASSESSMENT COMPLETED BY TRAYNOR ENVIRONMENTAL LTD APPENDIX C – OPW FLOOD MAP RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment RECEIVED: 08/09/2026 Site Specific Flood Risk Assessment RECEIVED: 08/09/2026