Environmental Impact Statement for Proposed Cluddaun Wind Farm Co. Mayo VOLUME 3 APPENDICES Appendix 12 A Viewshed Reference Point Selection Report
Viewshed Reference Point (VRP) Selection Report Cluddaun Wind Farm, Co. Mayo Prepared by February 2012
Viewshed Reference Point (VRP) Selection Introduction This report provides a rationale for the selection of viewshed reference points (VRP s) for the proposed Cluddaun Wind Farm, which is located in County Mayo some 10km to the north east of the settlement of Bellacorrick and 10km southwest of Ballycastle. This project comprises fifty one turbines that are arranged in a fairly loose, organic layout. The proposed turbines will have a blade tip height in the order of 150m. The VRP selection is based on computer generated visibility modeling, a desk survey and subsequent field work and uses a set of pre-established criteria to determine the likely relevance of each view. Methodology Generation of a Zone of Theoretical Visibility Malachy Walsh and Partners Ltd. carried out a computer automated study of the zone of theoretical visibility (ZTV). The purpose of this exercise is to identify the theoretical extent and degree of visibility of turbines. This is a theoretical exercise because it is based on topography only at 10m contour intervals and does not allow for intermittent screening provided by, for example, hedgerows, forests or buildings and does not involve the actual height of crests (but using the nearest 10m contour below). Thus the ZTV map, assuming no screening, represents a worst-case-scenario with respect to viewing exposure. For the purposes of this project a radius of 20km from the edge of the site was used for the ZTV to ensure reasonable coverage of the area. This is in line with the Wind Energy Development Guidelines, which suggest a radius of 20km for turbines in excess of 100m in height. Identification of Viewshed Reference Points as a Basis for Assessment The results of the ZTV analysis provide the basis for selection of key viewpoints from which to study the visual impacts of the proposed wind farm in detail. It is not warranted to include each and every single location that provides a view of the development as this would result in an unwieldy report and make it extremely difficult to draw out the key impacts arising from the project. Instead, the assessors endeavoured to select a variety of receptor types that would also provide views of the proposed wind farm from different distances, different angles and different contexts. These locations are significant because they represent, for example, centres of population and major transport routes. An initial broad set of potential views is generated from a desk study using the ZTV map. Each potential VRP is abbreviated to identify which of the following receptor types it represents; Receptor Type Key Views - from features of international or national importance; Designated Scenic Routes and Views; Local Community views; Centres of Population Major Routes; and Amenity and heritage features. Abbreviation KV DR LC CP MR AV
Some VRP s may be applicable to several receptor categories, in which case, they will be assessed under the group that best reflects that location s particular sensitivities. Such VRP s are of particular relevance to the proposal due to their multiple sensitivities. Fieldwork is then undertaken using the broad set of potential VRP s in order to systematically identify those that will actually provide a view of the proposed wind farm and those from which potential views are screened by vegetation or structures. This process involves the use of wireframe images to depict the proposed turbines within the terrain context seen from each potential VRP location. It is also an opportunity to experience the character and features of each location and make initial value judgements in relation to the sensitivity of each VRP. Where two or more VRP s with similar sensitivities are located within close proximity to each other, one may be selected in lieu of the others to represent the visual impact from that general viewing distance and angle. VRP selection by other Agencies It is a common occurrence that VRP locations are suggested or required by Statutory or non-statutory bodies with stakeholder interest in the site. The most likely source of VRP selection input is from the Local Authority that will assess the planning application or surrounding Local Authorities that may be impacted by the proposal. VRP locations may also be requested by An Taisce or other tourism, heritage or conservation groups with an interest in the area. If a third-party proposes a VRP, it can be evaluated for inclusion. Final VRP selection and use The VRP s selected at this stage of the project are those from which MosArt intend to assess the landscape and visual impacts of the proposal within the context of the project EIS. Notwithstanding, this VRP selection report is intended as a discussion document and VRP locations may be added to or removed from this set in consultation with the Planning Authority. Table 1 provides the grid coordinate location of the selected VRP s for the Cluddaun Wind Farm. The panoramic photographs included thereafter represent each of the selected VRP locations and can be used in conjunction with the grid reference coordinates by the Visualization Specialist to find the precise location of the VRP and to capture their own images required for photomontages. In this instance, the design of the scheme has not yet been finalized as it is the intention to minimize the visual impact at a number of the more sensitive receptor locations. The VRP s that currently represent these locations may not, therefore, be required depending on the extent of ZTV coverage for the final scheme. VRP s that may not ultimately be required for the visual impact assessment are marked with an asterisk.
Table 1 - Cluddaun Wind Farm Irish and Northern Irish Grid Coordinates for selected VRP locations VRP Ref. Eastings Northings Direction of View AV1* 112520 342342 SSW AV2 94135 323613 NE AV3 97609 316668 NNE CP1 110392 337242 SW CP2 96972 319930 NE CP3 123735 319912 NW CP4 113246 317443 NW DR1* 112327 340768 SSW DR2* 82527 337091 ESE DR3* 88832 333649 ESE Representative of views from: between 13 and 25 turbines on the ZTV map Landscape related amenity feature and tourist attractor all A regional walking route and tourist attractor between 13 and 25 turbines on the ZTV map A regional walking route and tourist attractor between 13 and 25 turbines on the ZTV map from its northwestern outskirts Worst case scenario views from one of the nearest settlements to the proposal site A regional road all One of the nearest settlements to the proposal site A national secondary road A location indicated as intermittently having a theoretical view of all from elevated locations at its northwestern outskirts One of the nearest settlements to the proposal site A place of spiritual significance all One of the nearest settlements to the proposal site A national secondary road between 13 and 25 turbines on the ZTV map A scenic route designation in the Mayo County Development Plan between 13 and 25 turbines on the ZTV map A scenic route designation in the Mayo County Development Plan A settlement and place of spiritual significance between 1 and 12 turbines on the ZTV map A scenic route designation in the Mayo County
DR4* 81383 330234 E DR5 103624 311584 N MR1 110568 332859 SW MR2 98529 318318 NNE MR3 100540 319016 NNE MR4 107504 317183 NNW LC1 107724 327107 NW Development Plan A regional road between 1 and 12 turbines on the ZTV map A scenic route designation in the Mayo County Development Plan all A scenic route designation in the Mayo County Development Plan A small settlement between 13 and 25 turbines on the ZTV map A regional road Views from local residences to the east between 13 and 25 turbines on the ZTV map A regional road all A national secondary road all A national secondary road all Views from local residences * VRP locations that may be dropped if refinement of the scheme layout places them outside of ZTV coverage. Note: Five VRP locations that were initially selected at the Desktop study stage were subsequently dropped at the fieldworks stage. These locations are indicated as points A E on the accompanying VRP selection map.
VRP Reference Images AV1 Car park / picnic spot at Downpatrick Head AV2- Western way at Tawnaghmore, 2km from Ballymonnelly Bridge
AV3 Western way at Derry Upper 2.5km from R312 junction CP1- Ballycastle CP2- Bellacorick
CP3 - Ballina CP4- N59 Crossmolina DR1 Sheeganear, 3km North of Ballycastle
DR2 Local Road at Pollatomish DR3 R314 3km West of Glenamoy DR4- Carrowmore Lake 2km South East of Barnatra
DR5 Local Road at Keenagh Beg MR1- R315 5km South of Ballycastle MR2- R312 2km Southeast of Bellacorick
MR3- N59 3km East of Bellacorick near Lough Dahybaun MR4- N59 5km West of Crossmolina at Carrowkeel LC1-4km West of R315 Garranard junction