STRATEGIC FLOOD RISK ASSESSMENT CORTOBER AREA PLAN WHICH FORMS PART OF VARIATION NUMBER 2 OF THE ROSCOMMON 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 County Roscommon 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, Strokestown 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 Athlone. 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 / Bellanamullia (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 River Shannon. 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. Roscommon County Development Plan 2008 – 2014: Cortober Area Plan SFRA Page 1 Strategic Flood Risk Assessment (SFRA) 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) Roscommon County Development Plan 2008 – 2014: Cortober Area Plan SFRA Page 2 Strategic Flood Risk Assessment (SFRA) 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. Roscommon County Development Plan 2008 – 2014: Cortober Area Plan SFRA Page 3 Strategic Flood Risk Assessment (SFRA) 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.