STRATEGIC FLOOD RISK ASSESSMENT

CORTOBER AREA PLAN WHICH FORMS PART OF VARIATION NUMBER 2 OF THE COUNTY DEVELOPMENT PLAN 2008 – 2014 (INCORPORATION OF THE CORE STRATEGY)

Prepared by: Forward Planning Roscommon County Council

Date: October 2012

Strategic Flood Risk Assessment (SFRA)

1. INTRODUCTION

1.1 BRIEF DESCRIPTION OF THE PLAN

The Cortober Area Plan is situated in to the south-west of Carrick-on-Shannon.

It has been proposed, as part of the revised Settlement Strategy incorporated in Variation Number 2 of the RCDP 2008 – 2014, that Cortober forms part of Tier 4: Key Satellite Villages, together with Hodson Bay/Barrymore, and Elphin. These centres have a more limited range of services than the tiers above and service provision often includes a range of retail and educational services, but limited financial, health and community services. These settlements should be further developed as residential and employment centres as well as service and local retail centres for their surrounding hinterland. Retail development is likely to be mainly convenience goods, with supermarkets and local shops serving the local town and the hinterland.

Similar to Tier 3 above and Tier 1, both Cortober (Carrick-on-Shannon environs) and Hodson Bay / Barrymore have strong connections with settlements in close proximity, i.e. Cortober with Carrick-on- Shannon and Hodson Bay / Barrymore with . This has influenced the way they have developed and will continue to do so. Whilst Hodson Bay / Barrymore will continue to develop as a largely residential settlement, Cortober acts as a smaller version of the Monksland / (Athlone West) area including both residential and commercial elements.

Residential development consists mainly of estate type housing, apartment and duplex type units and to a much lesser extent, single residential units. Much of this development has been constructed in the last decade.

In terms of commercial and retail development, Cortober has a range of outlets on the northern and southern sides of the N4 which would be typical of centres in a larger town. The range of services include; a cinema, the ESSO petrol filling station and Citroen car dealership, large convenience stores such as SuperValu and Lidl, as well as several comparison stores and retail warehousing units.

There are pockets of lands zoned for Business, Enterprise Park/Light Industry and Warehousing (BE) and Industrial uses (I) which front onto the N4. There is some scope for growth in BE but the industrial lands are largely subscribed.

Lands for Recreation, Amenity and Open Space (RA) are zoned on the ‘bull field’ which is situated south of the N4 and provides playing pitches for both GAA and soccer as well as associated dressing rooms. There are a number of other sporting facilities in and around Carrick on Shannon which range from a Golf Club, to indoor sports at the Aura Centre, and water sports associated with the .

The purpose of the Cortober Area Plan is to provide a framework for the proper planning and sustainable development of the area until 2014. It aims to co-ordinate the reasonable needs and aspirations of the people of the area, maximise the best-use of its resources, promote its economic and social development, while preserving the best of its natural and built environment. The aim of the Plan is to provide a clear phasing scheme for residential development which will consolidate development and provide for its sustainable expansion. The development envelope has contracted somewhat with a resultant reduction in the lands zoned for BE, Industrial and Leisure Tourism (LT). The lands provided for BE and LT as well as the Neighbourhood Centre (NC) zoning provides for the sustainable expansion of these uses over the plan period. The plan consists of a written statement and maps which give a graphic representation of the proposals of the plan. The plan includes policies and objectives for the development of, amongst others, social, physical and environmental infrastructure in a sustainable manner.

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2. FLOOD RISK ASSESSMENT

STAGE 1: FLOOD RISK IDENTIFICATION

This stage includes a review of existing information and the identification of any flooding or surface water management issues in the plan area which may warrant further investigation. A review of OPW data and local information has been carried out as well as other sources of information as indicated in the Planning System and Flood Risk Management Guidelines 2009 (see Appendix 1).

The Cortober AP area has the Shannon River on its north-eastern and eastern boundary, the Killukin River at a short distance from its south-eastern boundary; and another river/stream along its western boundary which joins the one along its northern boundary finally flowing into the Shannon River. Flooding has been evidenced from all these water bodies (see Map 1).

According to the OPW National Flood Hazard Mapping, there are a couple of flood points to the north-west of the plan area somewhat adjacent to the N4 i.e. Lough Eiden Tumna (recurring) and Lough Eiden Cloongownagh (recurring) (see Map 1). However, in terms of flood extents the areas adjacent to the River Shannon are more affected. Two extents are indicated which are related to specific flood events (see Map 1);

‹ the flood event of December 1954 which appears very angular and has discrepancies e.g. elevated areas surrounding the Killukin River are indicated as flooding; and, ‹ the winter of 1999/2000 which appears somewhat more accurate however there are places where it is indicated to flood on elevated ground, again near the housing estate north of the Killukin River.

Local information indicates that some of the areas indicated in the south eastern position of the AP area are quite elevated and are very unlikely to have flooded, as indicated on the 1954 and 1999/2000 OPW flood extents. There are however lands to the immediate north of the elevated areas which were subject to flooding in the recent 2009 flood event. Areas bounding the River Shannon in the east are low lying lands which are liable to be wet. Lands in this area are zoned for a combination of Leisure and Amenity (LA), Leisure Tourism (LT), Existing Residential (ER) and Mixed Residential and Commercial (MR) uses. Some of this LT and MR land has been removed from the development envelope, and some of the elevated MR land to the west which (from local information) is not liable to flood and zoned for Phase 2 NR uses.

In this area there are also alluvial deposits which indicate areas which have flooded in the past (see Map 1). These areas are quite extensive in the south-eastern corner of the AP area. In addition, alluvial deposits are indicated to the north, north-west and south-west. From local information, these very same areas are evidenced as low lying lands liable to be wet underfoot throughout the year. Some of the lands to the north have been exclused from the development envelope and lands in the south-western corner also.

The old 6 inch OS map indicates areas liable to flood along the Killukin River corridor. The older historic 6 inch OS maps indicate a “line of winter floods” which surrounds the Killukin River and roughly follows the boundaries of the alluvial deposits in this area. The river corridors are indicated at 25 metres on these maps. (See Figures 1 and 2)

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Figure 1: 6 inch map of Cortober indicating areas “Liable to Floods”

Figure 2: Historic 6 inch map of Cortober indicating the “Line if Winter Floods”

As the sites mentioned above fall within the AP development boundaries and could potentially be affected by development taking place as facilitated by the Variation Number 2 of the RCDP, the process moves onto Stage 2: Initial Flood Risk Assessment.

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STAGE 2 : INITIAL FLOOD RISK ASSESSMENT

The purpose of the initial FRA is to ensure that all relevant flood risk issues are assessed in relation to the decisions to be made. It also ensures that potential conflicts between flood risk and development are addressed to the appropriate level of detail.

As indicated above, there are several flood extents which traverse the AP area and these can be grouped as follows (see Map 1);

1. Those in and around the Killukin River; 2. Those in and around the River Shannon; and, 3. Those associated with the river/stream along its western boundary which joins the one along its northern boundary finally flowing into the Shannon River.

1. As mentioned above, some of the lands which are indicated on the OPW flood extents of 1954 and 1999/2000 are on elevated lands just below the 50 metre contour which are known locally not to flood. A portion of these lands adjacent to the Glen Patrick Housing Estate which were previously zoned for MR are now zoned for Phase 2 NR development.

Adjacent portions which are indicated to the east of these lands, which were previously zoned in 2008 for MR and some for LT, and are indicated on all the OPW databases, as well as where alluvial deposits are in evidence, and which were flooded during the 2009 floods, have been removed from the development envelope altogether. It is also recommended that Greenbelt buffer strips be zoned on either side of the rivers in this area to protect their ecological functioning. By doing these things, the avoidance principle of the sequential approach has been met.

2. Lands in and around the River Shannon to the north-east of the AP which are indicated as flooding in the 1999/2000 floods and where alluvial deposits exist, are zoned for a mix of LT, LA, Greenbelt (GB) as well as ER. The ER zoning in this area has been built upon and some of this is now zoned for LT to allow these uses in the future. The Greenbelt zoning is on lands adjacent to the river which provides an amenity area with benches for people to take advantage of the views of the river and marina. These zonings together with the LA zoning have remained unchanged from the 2008 AP. The LA zoning is situated on the River Shannon where people are able to participate in water sports etc. No additional intensive development is proposed in this area which would impact on flood risk.

3. Lands to the north, adjacent to the river/stream which flows into the River Shannon, are indicated as flooding in the 1954 and 1999/2000 floods, a portion to the east in the 2009 floods, the remaining portions west as low lying lands liable to be wet, and where alluvial deposits exist. These lands have been zoned for NC, MR and BE. The NC portions are built upon, however the MR and BE portions are Greenfield sites. All lands to the west of the NC on the northern side of the N4 zoned for greenbelt purposes to protect the ecological functioning of the river. By doing this, the avoidance principle of the sequential approach has been met.

4. Certain of the lands on the south western corner of the development envelope have alluvial deposits which indicate that it has flooded in the past. There is no noticeable difference between the level of the river/stream and the level of the adjoining lands which includes that of the Shannon Gael housing estate. The river has also been used for the discharge of stormwater which is becoming increasingly problematic and more intensive development in this area could pose addition risks of flooding of these lands and those further downstream. It is therefore considered appropriate to provide a Greenbelt buffer along the full length of the river/stream, including the northern stretch to the River Shannon, which will serve as areas for attenuation and ensure the ecological functioning of the rivers. By doing this, the avoidance principle of the sequential approach has been met.

In addition, the following objectives have been included in the plan which indicates the following:

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Objective Within the Cortober AP area, RCC shall;

° avoid inappropriate development in areas at risk of flooding; ° avoid new developments increasing flood risk elsewhere, including that which may arise from surface run-off; ° ensure effective management of residual risks for development permitted in floodplains; ° avoid unnecessary restriction of national, regional or local economic and social growth; ° improve the understanding of flood risk amongst relevant stakeholders; and ° ensure that the requirements of EU and national law in relation to the natural environment and nature conservation are complied with at all stages of flood risk management

Objective Require a Flood Risk (Impact) Assessment and Management Plan for all significant development impacting on flood risk areas to identify potential loss of floodplain storage and how it would be offset in order to minimise impact on the river flood regime.

Therefore, as mitigation measures have been identified to ensure, firstly that any development taking place will not exacerbate the existing problems and secondly, which will prevent the recurrence of flooding, it is not considered necessary to proceed to Stage 3, Detailed Flood Risk Assessment.

STAGE 3 : DETAILED FLOOD RISK ASSESSMENT

A detailed flood risk assessment is required when Stages 1 and 2 “indicate that a proposed development or area of possible zoning may be subject to a significant flood risk.” (Appendix A, p. 12)

The purpose of this stage is “to assess flood risk issues in sufficient detail and to provide a quantitative appraisal of potential flood risk to a proposed or existing development, of its potential impact on flood risk elsewhere and of the effectiveness of any proposed mitigation measures. This will typically involve use of an existing or construction of a hydraulic model of the river or coastal cell across a wide enough area to appreciate the catchment wide impact and hydrological processes involved.” (Appendix A, p. 8)

As indicated in Stage 1 and 2 above, it was concluded that there was no need to proceed to Stage 3. A Flood Risk and Protection Strategy is detailed within the Cortober Area Plan and flowing from this, policies and objectives address the needs associated with flood risk and protection.

It is therefore considered that RCC have taken a precautionary approach in terms of its zoning and applied the avoidance principle of the sequential approach in the Cortober AP and it is therefore not considered necessary to proceed to Stage 3 for this Variation process.

3. THE RELEVANCE OF THE PLAN FOR THE IMPLEMENTATION OF EUROPEAN UNION LEGISLATION ON THE ENVIRONEMENT (E.G. PLANS LINKED TO WASTE MANAGEMENT OR WATER PROTECTION)

Issues relating to EU legislation on the environment have been addressed in the Roscommon County Development Plan 2008 – 2014, Variation Number 2 of the RCDP 2008 – 2014 as well as the adopted LAPs.

4. CONCLUSION

The process recommended in the Guidelines for Planning Authorities: The Planning System and Flood Risk Management (2009) have been used to assess the Cortober Area Plan which is part of Variation Number 2 of the RCDP 2008-2014. As a result of the initial Flood Risk Identification and Initial Flood Risk Assessment (Stages 1 & 2) it has been concluded that as mitigation measures have been identified to ensure firstly that any development taking place will not exacerbate the existing problems and secondly which will prevent the recurrence of flooding, it is not considered necessary to subject the Cortober Area Plan to Stage 3, Detailed Flood Risk Assessment.

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APPENDIX 1 Table A4: Information sources appropriate for the identification of flood risk 1 Scale of Assessment Used in Information Source Comment SFRA Assessment COUNTY OPW Preliminary Flood Risk Assessment indicative fluvial flood Preliminary information provided recently as part of mapping information √ No maps; viewed but not taken as definitive until officially released National Coastal Protection Strategy Study flood and coastal erosion √ N/A Not applicable. risk maps; Predictive and historic flood maps, and Benefitting Lands Maps, such √ Yes Only historic flood mapping is currently available. as those at http://www.floodmaps.ie; Predictive flood maps produced under the CFRAM Studies; √ No Not currently available. River Basin Management Plans and reports; √ Yes The Shannon River Basin Management Plan 2009-2015 was reviewed. Indicative assessment of existing flood risk under Preliminary Flood √ No Preliminary Flood Risk Assessment not yet available. Risk Assessment; Previous Strategic Flood Risk Assessments; √ No No strategic flood risk assessments available

Expert advice from OPW who may be able to provide reports containing the results of detailed modelling and flood-mapping studies, √ Yes Historic flood maps were reviewed. including critical drainage areas, and information on historic flood events, including flooding from all sources;

Consultation with Local Authorities who may be able to provide √ Yes Water Services Section and Road Design Section of RCC consulted. knowledge on historic flood events and local studies etc.

Topographical maps, in particular digital elevation models produced by Most up-to-date OSI aerial photography available for the area was reviewed i.e. √ Yes aerial survey or ground survey techniques; 2004-2006. Not applicable, no flood defence measures in the area. The N4 has been raised Information on flood defence condition and √ N/A in recent years which does provide somewhat of a flood defence for lands to the performance; south of it. Alluvial deposit maps of the Geological Survey of Ireland (which Soil and subsoil mapping was reviewed as part of the report and alluvial P Yes would allow the potential for the implementation of source control and deposits are indicated on the maps.

1 Page 9-10, Technical Appendices, The Planning System and Flood Risk Management, Guidelines for Planning Authorities, DEHLG, November 2009

Roscommon County Development Plan 2008 – 2014: Cortober Area Plan SFRA Page 7 Strategic Flood Risk Assessment (SFRA) infiltration techniques, groundwater and overland flood risk to be assessed). These maps, while not providing full coverage, can indicate areas that have flooded in the past (the source of the alluvium) and may be particularly useful at the early stages of the FRA process where no other information is available;

‘Liable to flood’ markings on the old ‘6 Inch’ maps; P Yes These maps were used as part of the report.

Local libraries and newspaper reports; √ No Local information provided below Interviews with sections of RCC. Local information was used in the Interviews with local people, local history / natural history societies etc; S Yes compilation of the analysis of flood risk and protection.

Walkover survey to assess potential sources of flooding, likely routes Site visits carried out for the review of the AP. Also photographic survey for flood waters and the site’s key features, including flood defences, S Yes during 2009 flooding. and their condition; and National, regional and local spatial plans, such as the National Spatial Strategy (NSS), regional planning guidelines (RPGs), development Plans reviewed include the NSS, RPGs for the West 2010-2022, RCDP 2008- √ Yes plans and local area plans provide key information on existing and 2014 and Cortober AP. potential future receptors.

P = Possible source of information but not primary or essential, especially if better information exists from more detailed studies. S = Selective source depending on scale of issues and could be delayed until initial flood risk assessment stage. √ = Primary source. This will be readily available information once CFRAMS have been completed, but in order to examine all development allocations within a plan further research from secondary sources will be required. N/A = Not appropriate or not applicable.

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