Ryewater Arterial Drainage Scheme
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Office of Public Works Arterial Drainage Maintenance Works - Ryewater Arterial Drainage Scheme Natura Impact Statement 2016 to 2020 Office of Public Works Main Street Headford Co Galway Ireland JBA Project Manager Tom Sampson 24 Grove Island Corbally Limerick Ireland Revision History Revision Ref / Date Issued Amendments Issued to Nathy Gilligan, OPW Draft Report / October 2015 Tony Brew, OPW Revised description of Nathy Gilligan, OPW Final Report / November 2015 proposed maintenance works Tony Brew, OPW Final report revised following Nathy Gilligan, OPW V6.0 /July 2016 Tufa Springs Surveys in 2016 Tony Brew, OPW Revisions following client Nathy Gilligan, OPW V7.0 / August 2016 review Tony Brew, OPW Change of report title and Nathy Gilligan, OPW V8.0 / August 2016 amendment to concluding text Tony Brew, OPW Contract This report describes work commissioned by the Office of Public Works, by a letter dated 05/06/2015. The Office of Public Works representative for the contract was Tony Brew. Laura Thomas, Tom Sampson and Anne Murray of JBA Consulting carried out this work. Prepared by .................................................. Anne Murray BSc MCIEEM Senior Ecologist Reviewed by ................................................. Declan Egan Environmental Director Purpose This document has been prepared as a Final Report for the OPW. JBA Consulting accepts no responsibility or liability for any use that is made of this document other than by the Client for the purposes for which it was originally commissioned and prepared. JBA Consulting has no liability regarding the use of this report except to the OPW. Copyright © JBA Consulting Engineers and Scientists Ltd 2016 Carbon Footprint A printed copy of the main text in this document will result in a carbon footprint of 140g if 100% post-consumer recycled paper is used and 140g if primary-source paper is used. These figures assume the report is printed in black and white on A4 paper and in duplex. JBA is aiming to reduce its per capita carbon emissions. 2015s2916 Ryewater Natura Impact Statement v8.0 i Executive Summary JBA Consulting has been commissioned by the Office of Public Works (OPW) to provide environmental consultancy services in relation to statutory arterial drainage maintenance activities for the period 2016-2020. In 2014, following the methodology outlined in Ryan Hanley (2014a), a screening assessment was conducted to assess the likely significant effects on Natura 2000 sites of the proposed drainage maintenance activities in the Ryewater Arterial Drainage Scheme in accordance with Article 6(3) of the Habitats Directive (Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora). Three source > pathway > receptor chains were examined to assess the likely impact of drainage maintenance activities on Natura 2000 sites; surface water, land and air, and groundwater pathways. From the screening exercise it was determined that significant likely effects may arise on the following Natura 2000 sites as a result of OPW drainage maintenance activities in the Ryewater Drainage Scheme. Rye Water Valley/Carton SAC (001398) There is potential for the conservation interests of the Natura 2000 site to be impacted by all pathways, given that the habitats present are groundwater dependent and have connectivity to surface water, and that scheme watercourses fall within the site itself. As a result, it was necessary to produce a Natura Impact Statement (NIS) in support of a Stage 2 Appropriate Assessment to further examine the potential direct and indirect impacts of the proposed works on the integrity and interest features of the above Natura 2000 site, alone and in-combination with other plans and projects, taking into account the site's structure, function and conservation objectives. Further examination of the potential sources of impact on the Natura 2000 site above, looking at groundwater pathways, was conducted. Where potentially significant adverse impacts were identified, a range of mitigation and avoidance measures have been stipulated to help offset them. The Final version of the NIS concluded that more information was required on the location of the tufa springs in order to avoid these during the proposed works. As a result, a survey of the tufa springs was carried out by JBA to identify any springs, in order to avoid these. The survey has been incorporated into this NIS. The survey also identified springs which are not tufa forming but that should also be avoided to ensure that no impacts to groundwater occur. 2015s2916 Ryewater Natura Impact Statement v8.0 ii Contents Executive Summary .......................................................................................................... ii 1 Introduction .......................................................................................................... 1 1.1 Background ............................................................................................................ 1 1.2 Legislative Context ................................................................................................ 1 1.3 Appropriate Assessment Process ......................................................................... 1 1.4 Methodology .......................................................................................................... 3 2 Arterial Drainage Maintenance ........................................................................... 4 2.1 Background ............................................................................................................ 4 2.2 Drainage Maintenance Activities ........................................................................... 4 2.3 The Ryewater Arterial Drainage Scheme .............................................................. 9 2.4 Drainage Maintenance Works Proposed for the Ryewater Arterial Drainage Scheme .................................................................................................................. 10 3 Screening Assessment Results ......................................................................... 15 3.1 Introduction ............................................................................................................ 15 3.2 Screening Assessment Conclusions ..................................................................... 16 4 Natura 2000 sites within the Zone of Influence of Drainage Maintenance Activities ............................................................................................................... 18 4.1 Introduction ............................................................................................................ 18 4.2 Rye Water Valley/Carton SAC (001398) ............................................................... 18 5 Appropriate Assessment .................................................................................... 21 5.1 Introduction ............................................................................................................ 21 5.2 Tufa Springs Survey .............................................................................................. 21 5.3 Impact Assessment ............................................................................................... 21 5.4 Identification of Potential Sources of Impact ......................................................... 21 5.5 Avoidance Measures ............................................................................................. 24 5.6 Mitigation Measures ............................................................................................... 24 6 Avoidance and Mitigation Measures ................................................................. 31 6.1 Introduction ............................................................................................................ 31 7 Conclusions ......................................................................................................... 32 7.1 Future works between Sandsford Bridge to the Aquaduct at Louisa Bridge ......... 32 Appendices........................................................................................................................ I A OPW Arterial Drainage Maintenance Service: Environmental Management Protocols and Standard Operating Procedures ............................................... I B Ecological walkover survey of Ryewater Valley/Carton SAC ......................... I C Tufa Springs Survey ............................................................................................ I 2015s2916 Ryewater Natura Impact Statement v8.0 List of Figures Figure 1-1: The Appropriate Assessment Process (from: Appropriate Assessment of Plans and Projects in Ireland - Guidance for Planning Authorities, DEHLG, 2009) ................................................................................................................. 2 Figure 2-1: Map of the Ryewater Arterial Drainage Scheme ............................................. 10 Figure 2-2: Kildare and Sandsford Bridge .......................................................................... 11 Figure 2-3: Sandsford Bridge to Aqueduct ......................................................................... 12 Figure 2-4: Aqueduct to Confey College ............................................................................ 13 Figure 2-5: Aqueduct to Distillery Road Retirement Home ................................................ 14 Figure 3-1: Channels with potential impacts via surface water pathways and the