Greater Dublin Drainage Project Irish Water Environmental Impact Assessment Report: Volume 3 Part A of 6 Chapter 16: Archaeological, Architectural and Cultural Heritage June 2018 Envir onmental Impact Assessment Report: Vol ume 3 Part A of 6 Irish Water Environmental Impact Assessment Report: Volume 3 Part A of 6 Contents 16. Archaeological, Architectural and Cultural Heritage ............................................................................. 1 16.1 Introduction .................................................................................................................................................. 2 16.1.1 Consultation ................................................................................................................................................. 4 16.2 Methodology ................................................................................................................................................ 4 16.2.1 Background ................................................................................................................................................. 5 16.2.2 Paper Survey ............................................................................................................................................... 5 16.2.3 Field Inspection ........................................................................................................................................... 8 16.2.4 Geophysical Survey..................................................................................................................................... 8 16.2.5 Archaeological Testing ................................................................................................................................ 8 16.2.6 Underwater Archaeological Assessment .................................................................................................... 9 16.2.7 Definitions .................................................................................................................................................... 9 16.3 Baseline Environment ................................................................................................................................. 9 16.3.1 Archaeological and Historic Background .................................................................................................... 9 16.3.2 Recorded Archaeological Heritage Sites .................................................................................................. 16 16.3.3 Recorded Shipwrecks ............................................................................................................................... 19 16.3.4 Stray Archaeological Finds ........................................................................................................................ 21 16.3.5 Recorded Built Heritage ............................................................................................................................ 21 16.3.6 Areas of Archaeological Potential ............................................................................................................. 23 16.3.7 Designed Landscapes ............................................................................................................................... 24 16.3.8 Unrecorded Recorded Built Heritage ........................................................................................................ 26 16.3.9 Townlands ................................................................................................................................................. 27 16.3.10 Previous Archaeological Fieldwork Carried Out Within the Study Area .................................................... 29 16.3.11 Summary of Geophysical Survey at Proposed Wastewater Treatment Plant .......................................... 32 16.3.12 Summary of Geophysical Survey Within the Proposed Orbital Sewer Route, Outfall Pipeline Route (Land Based Section) and Abbotstown Pumping Station ......................................................................... 33 16.3.13 Summary of Archaeological Testing at the Proposed Wastewater Treatment Plant ................................ 34 16.3.14 Summary of Intertidal Survey .................................................................................................................... 34 16.3.15 Summary of Marine Archaeological Geophysical Survey ......................................................................... 35 16.3.16 Construction Phase ................................................................................................................................... 36 16.4 Appraisal Method Used for Assessment of Impacts ................................................................................. 36 16.5 Impact of the Proposed Project ................................................................................................................. 37 16.5.1 Construction Phase ................................................................................................................................... 37 16.5.2 Operational Phase ..................................................................................................................................... 46 16.6 Mitigation Measures .................................................................................................................................. 49 16.6.1 Construction Phase ................................................................................................................................... 49 32102902/EIAR/16 ii Environmental Impact Assessment Report: Volume 3 Part A of 6 16.6.2 Operational Phase ..................................................................................................................................... 51 16.7 Residual Impacts ....................................................................................................................................... 52 16.8 Cumulative Impact and Impact Interrelations ............................................................................................ 52 16.9 Difficulties Encountered in Compiling Required Information ..................................................................... 52 16.10 References ................................................................................................................................................ 52 32102902/EIAR/16 iii Environmental Impact Assessment Report: Volume 3 Part A of 6 16. Archaeological, Architectural and Cultural Heritage The purpose of this assessment is to identify and assess the significance of and impacts to any known or proposed archaeological, architectural and cultural heritage associated with the Greater Dublin Drainage Project (hereafter referred to as the Proposed Project). There are a total of 50 sites or groups of archaeological heritage sites recorded within the study area of the Proposed Project. Of these: None are classed as National Monuments or further protected with a Preservation Order; Three very significant negative direct impacts are predicted upon recorded archaeological sites, along with five significant negative direct impacts; and Direct moderate negative impacts will occur in relation to two further sites. The remaining impacts are indirect or neutral, and in four cases no impact is predicted. A total of 28 structures were recorded within the study area of the Proposed Project which are listed within the Register of Protected Structures or within the National Inventory of Architectural Heritage. No significant negative impacts are predicted upon the recorded built heritage resource. In addition to the above, multiple Areas of Archaeological Potential have been identified within the study area, along with a number of previously unrecorded buildings of architectural heritage merit, designed landscapes and townland boundary crossings. Potential impacts on these sites vary from direct to indirect or neutral. The significance of the impacts ranges from slight to very significant (negative). An extensive programme of archaeological test trenching will be carried out at each archaeological site identified prior to construction. Testing will also be carried out within the lands required for the overall Proposed Project by an archaeologist under licence to the Department of Culture, Heritage and the Gaeltacht. This work will provide information on the nature and extent of the remains within the Proposed Project study area, enabling the compilation of a programme of works to ensure the sites are fully preserved by record. A proposed outfall pipeline route will be constructed from the proposed Wastewater Treatment Plant to a marine discharge point. The marine environment possesses archaeological potential due to the presence of shipwrecks, which are protected under the National Monuments Act 1930 (as amended). The Shipwreck Inventory records 27 shipwrecks within the vicinity of Portmarnock Strand. No specific shipwrecks have been identified that will be directly impacted upon. However, the potential remains that archaeological deposits or features associated with shipwrecks remain buried at deeper levels beneath the current seabed. Dredging activity has the potential, directly and negatively, to impact these potential remains to a significant or profound degree. With regards to the marine archaeological resource, all dredging will be monitored by a specialist underwater archaeologist under licence to the National