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N11/N25 Oilgate to Rosslare Harbour Appendix E. Ecology Reports E.1. Aquatic Ecology and Fisheries Report 247517/IWE/CCT/09/C 06 September 2011 247517-09-C Route Selection Report Part 2 Appendices.doc E-1 N11/N25 Oilgate to Rosslare Harbour This page left intentionally blank for pagination. 247517/IWE/CCT/09/C 06 September 2011 247517-09-C Route Selection Report Part 2 Appendices.doc E-2 N11/N25 Oilgate to Rosslare Road Scheme Route Selection Report Aquatic Ecology and Fisheries Version 3-12-2010 Tait Business Centre, Dominic Street, Limerick City, Ireland. t. +353 61 419477, f. +353 61 414315 e. [email protected] w. www.ecofact.ie N11 / N25 Oilgate to Rosslare Aquatic Ecology and Fisheries December 2010 EXECUTIVE SUMMARY This chapter provides a water quality, fisheries and aquatic ecological assessment of water features potentially affected by the route options under consideration for the proposed N11 / N25 Oilgate to Rosslare Road scheme. Water bodies in the study area were identified using OS mapping. Information on important aquatic ecological features, water quality and protected aquatic species was collated by desktop review including examination of websites (SERBD, EPA, NPWS, IFI). Field surveys including biological sampling, river corridor assessments and searches for protected species were carried out on representative watercourses. All watercourses down to 1st order streams indicated on 1:50,000 scale OSI maps were assessed and rated using NRA guidelines in terms of fisheries value and ecological value and also using the EPA’s Envision mapping tool to identify rivers, lakes, catchment boundaries, and water quality. The most significant watercourse within the study area is the River Slaney which is within the River Slaney Valley SAC, an internationally important site. The site supports populations of several species listed on Annex II of the EU Habitats Directive including the three Lampreys - Sea Lamprey (Petromyzon marinus), River Lamprey (Lampetra fluviatilis) and Brook Lamprey (Lampetra planeri), Otter (Lutra lutra), Salmon (Salmo salar), Freshwater Pearl Mussel (Margaritifera margaritifera) and in the tidal stretches, Twaite Shad (Alosa fallax) and Allis Shad (Alosa alosa). The River Slaney is also designated Salmonid Water under the EU Freshwater Fish Directive. It is also considered a nationally important watercourse in terms of Atlantic salmon and sea trout angling. Furthermore, Wexford Harbour is a designated shellfish area. The River Slaney within the study area is also listed as RPA Nutrient Sensitive Area. The other watercourses in the study area are not considered as significant in terms of aquatic ecology and fisheries resources as the Slaney itself. These included watercourses in the Sow, Corock, Bishop’s Water and Bridgetown / Duncormick catchments. These aquatic areas ranged in value from High Value, Local Importance to Low Value, Local Importance, based on the NRA ‘Guidelines for the Assessment of Ecological Impacts of National Road Schemes’ (Rev.2, NRA 2009) for rating the value of watercourses. Indeed, most of the watercourses in the study area were minor streams, many of which were degraded and considered of little fisheries and aquatic ecological value. These watercourses drain mainly agricultural lands but some contained Annex II listed species. The most important of these watercourses were the larger tributaries of the Slaney and the upper reaches of Mulmontry River, the latter a part of a separate catchment draining into the sea on the south coast of Wexford. These watercourses have been rated ‘High Value, Locally Important (C)’ due to the presence of protected aquatic species listed on Annex II of the EU Habitats Directive together with Good ecological status in some cases. The proposed scheme has the potential to significantly impact on water quality and aquatic ecological resources in the absence of suitable and proportional mitigation. All route options cross the River Slaney and all cross a number of other watercourses. Any impacts on the River Slaney main channel would constitute impacts on the Slaney River Valley cSAC. Similarly, impacts on tributaries of the Slaney could indirectly impact on this river. From an assessment of the proposed route options and an evaluation of the potential scale of impacts arising from the proposed watercourses crossings associated with each route, a preferred route option has emerged in terms of aquatic ecology and fisheries. This is the ‘B’ option, which would cross the River Slaney near/at the existing crossing. In order of preference, the route option choice is B, A, D, C, E, G, F and H. It is noted however that any of the proposed routes could be built with the provision and implementation of suitable mitigation. The crossing points C1 and C1a are rated the same in relation to impacts on the River Slaney. It is emphasised that this assessment is based on the aquatic ecological and fisheries constraints posed by the proposed scheme. It is considered that the preferential ranking and benefits of the preferred route in this regard may be outweighed by engineering and terrestrial ecology constraints, with respect to a full environmental assessment of the route corridors. www.ecofact.ie 2 N11 / N25 Oilgate to Rosslare Aquatic Ecology and Fisheries December 2010 TABLE OF CONTENTS 1 INTRODUCTION .................................................................................................................................... 5 2 METHODOLOGY.................................................................................................................................... 6 2.1 DESK STUDY ..............................................................................................................................................6 2.2 FIELD SURVEYS ..........................................................................................................................................6 2.3 CONSULTATION..........................................................................................................................................7 2.4 ECOLOGICAL EVALUATION............................................................................................................................7 2.5 LEGISLATIVE CONTEXT .................................................................................................................................8 3 RECEIVING ENVIRONMENT ................................................................................................................. 10 3.1 RIVER SLANEY CATCHMENT ........................................................................................................................10 3.1.1 Overview of Slaney catchment..........................................................................................10 3.1.2 Designated areas ..............................................................................................................11 3.1.3 Water Quality.....................................................................................................................12 3.1.4 Habitats and flora ..............................................................................................................15 3.1.5 Aquatic ecology.................................................................................................................17 3.1.6 Additional observations .....................................................................................................21 3.2 SOW COASTAL CATCHMENT .......................................................................................................................22 3.2.1 Catchment overview..........................................................................................................22 3.2.2 Designated areas ..............................................................................................................22 3.2.3 Water quality .....................................................................................................................22 3.2.4 Habitats and flora ..............................................................................................................23 3.2.5 Aquatic ecology.................................................................................................................23 3.2.6 Other observations............................................................................................................24 3.3 COROCK CATCHMENT................................................................................................................................24 3.3.1 Catchment overview..........................................................................................................24 3.3.2 Designated areas ..............................................................................................................24 3.3.3 Water quality .....................................................................................................................25 3.3.4 Habitats and flora ..............................................................................................................25 3.3.5 Aquatic ecology.................................................................................................................25 3.4 BISHOPS WATER COASTAL CATCHMENT.........................................................................................................26 3.4.1 Catchment overview..........................................................................................................26