Making Room for the River Dodder Thesis Statement Mitigating against flood risk, biodiversity loss and climate change by restoring the River Dodder’s natural floodplain and habitats. Returning the land to the river and adapting to climate change. Alix Bent Landscape Studio 4B 2020 Abstract Our river ecosystems are struggling to manage the increased storm water runoff caused by climate change and the consequent loss of biodiversity coupled with the social and financial costs for residential homes along the river banks. This thesis illustrates how landscape interventions can safeguard the River Dodder from the impact of climate change by expanding its floodplains, while enhancing the natural characteristics of the river for recreation and conservation. The landscape developments proposed for the site areas at Rathfarnham Shopping Centre and Oldbawn have been inspired by some of the successful river projects undertaken in Europe. i CONTENTS Pages 1 EXECUTIVE SUMMARY 1 5 DESIGN PROCESS 19 5.1 Selection of Sites along the Dodder 5.2 Landscape Development Influences 5.3 Management of Upstream Areas 2 INTRODUCTION 2 5.4 Re-wilding and Tree planting to prevent Floodplain 5.5 Site 1. Rathfarnham Shopping Centre 2.1 Flooding as a Direct Effect of Climate Change 5.6 Site 2. Oldbawn 2.2 Mitigating and Adapting to Flooding 2.3 Rivers and their Importance 6 CONCLUSION 43 3 LANDSCAPE RESEARCH 6 3.1 Switzerland ‘Designing a River Garden’ 3.2 The Netherlands ‘Room for the River’ 7 REFERENCES AND BIBLIOGRAPHY 4 SITE ANALYSIS 11 4.1 Description of the Dodder 4.2 Topography 4.3 Flooding 4.4 Land use and Land Management 4.5 Geological Bedrock 4.6 Soil Permeability ii List of Figures and their References All drawings and photos not referenced are original works by the author Cover Sheet: The River Dodder (photo by author) Fig 1. Ireland Map of Ireland (by author) Fig 2. The River Dodder Catchment Area (Google maps, 2020) (by author) Fig 3. Flooding at Nutgrove Avenue Ryan, S. (2014). Photos: The floods have arrived. [online] TheJournal.ie. Available at: https://www.thejournal.ie/flooding-photos-1779929-Nov2014/ [Accessed 18 Dec. 2019]. Fig 4. Plan of the Renaturation of the River Aire Landezine.com. 2020. Renaturation Of The River Aire, Geneva « Landscape Architecture Platform | Landezine. [online] Available at: <http://landezine.com/index. php/2016/06/renaturation-of-the-river-aire-geneva/> [Accessed 17 May 2020]. Fig 5. Photograph showing the evolution of the River Aire Landezine.com. 2020. Renaturation Of The River Aire, Geneva « Landscape Architecture Platform | Landezine. [online] Available at: <http://landezine.com/index. php/2016/06/renaturation-of-the-river-aire-geneva/> [Accessed 17 May 2020]. Fig 6. Before Flood Prevention Measures at the River Waal Landezine.com. (2016). Room for the River, Nijmegen by H+N+S Landscape Architects « Landscape Architecture Platform | Landezine. [online] Available at: http:// landezine.com/index.php/2016/08/room-for-the-river-nijmegen-by-hns-landscape-architects/ [Accessed 1 Dec. 2019]. Fig 7. After Flood Prevention Measures at the River Waal. Landezine.com. (2016). Room for the River, Nijmegen by H+N+S Landscape Architects « Landscape Architecture Platform | Landezine. [online] Available at: http:// landezine.com/index.php/2016/08/room-for-the-river-nijmegen-by-hns-landscape-architects/ [Accessed 1 Dec. 2019]. Fig 8. Nijmegen’s new flood protection for the River Waal. Landezine.com. (2016). Room for the River, Nijmegen by H+N+S Landscape Architects « Landscape Architecture Platform | Landezine. [online] Available at: http:// landezine.com/index.php/2016/08/room-for-the-river-nijmegen-by-hns-landscape-architects/ [Accessed 1 Dec. 2019]. iii Fig 9. People using Nijmegan’s new flood protection for the River Waal. Landscape Architecture Platform | Landezine. [online] Available at: http://landezine.com/index.php/2016/08/room-for-the-river-nijmegen-by-hns-landscape-architects/ [Accessed 1 Dec. 2019]. Fig 10. Map of the Dodder Catchment area (reproduced by author) RPS (2012). [online] Dublincity.ie. Available at: https://www.dublincity.ie/sites/default/files/content/WaterWasteEnvironment/waterprojects/Documents/IBE0064_ Dodder%20Final%20Plan_120229.pdf [Accessed 20 Nov. 2019]. pp. 14 Fig 11. Map indicating the Topogarphy of the River Dooder (reproduced by author) Mapping, OSI. (2019). Discovery Series Digital. [online] Osi.ie. Available at: https://www.osi.ie/products/professional-mapping/discovery-series-digital/ [Accessed 17 Nov. 2019]. Fig 12. Flood Map of Dodder (reproduced by author) Floodinfo.ie. (2019). Flood Plans - OPW Flood Risk Management. [online] Available at: https://www.floodinfo.ie/map/floodplans/ [Accessed 18 Nov. 2019]. Fig 13 Map indicating Land use and land management surrounding the Dodder (reproduced by author) Enviromap.ie. (2019). The ESM Webtool | Bringing Environmental Assessment to your fingertips. [online] Available at: https://www.enviromap.ie/ [Accessed 18 Dec. 2019].. Fig 14. Geological bedrock (reproduced by author) Enviromap.ie. (2019). The ESM Webtool | Bringing Environmental Assessment to your fingertips. [online] Available at: https://www.enviromap.ie/ [Accessed 18 Dec. 2019]. Fig 15. Map indicating soil permiability surrounding the Dodder (reproduced by author) Enviromap.ie. (2019). The ESM Webtool | Bringing Environmental Assessment to your fingertips. [online] Available at: https://www.enviromap.ie/ [Accessed 1 Feb. 2020]. Fig 16. South Couth Dublin Development plan 2016-2022 (reproduced by author) SDCC. 2020. Development Plan 2016 - 2022. [online] Available at: <https://www.sdcc.ie/en/services/planning/development-plan/plan-2016-2022/> [Accessed 2 March 2020]. Fig 17. Natura 2000 sites within the catchment(reproduced by author) RPS (2012). [online] Dublincity.ie. Available at: https://www.dublincity.ie/sites/default/files/content/WaterWasteEnvironment/waterprojects/Documents/IBE0064_ Dodder%20Final%20Plan_120229.pdf [Accessed 20 Nov. 2019]. pp. 55 iv 1. EXECUTIVE SUMMARY The climate and biodiversity crisis that the world faces today, recognised in the various declarations made by an increasing number of countries since May 2019, (Cunningham, 2019) means action must be taken, sometimes drastically to mitigate its potentially disastrous effects. Climate change has a direct effect on the hydrological cycle, as it intensifies, as air temperatures increase, more water evaporates; warmer air also holds more water vapour, which consequently leads to more intense rainstorms, causing more problems such as increased and more frequent flooding around the world. (Climate Reality, 2016) Climate change has also led to habitat loss, biodiversity loss, and pollution, which in turn contributes to climate change. (Harvey, 2018) I am particularly interested in the potential of restoration and improvement of degraded river systems in adapting to climate change, and how the creation of floodplains can be used in landscape developments to create more sustainable environments, protection of biodiversity and natural habitats. Rivers flowing through densely populated counties like Dublin, present particularly challenging issues around rainwater runoff generated by a combination of climate change and residential and commercial development. The Dodder is one such river in Dublin that faces all these challenges. To inform my thinking on this subject I have researched the principles of how to mitigate and adapt to increased flooding of rivers. I have also looked at the effects of rainwater runoff on the environment, in both a local and global context; how climate change can be mitigated and managed, and how environments can be adapted by restoring the natural ecosystems providing much needed amenities to residential developments. This thesis will analyse examine and review how countries like Switzerland The Netherlands and have successfully developed landscape solutions to allow rivers to expand their flood plains to cater for increased rainfall and at the same time create amenities that will not only benefit people but will also increase biodiversity for plants and wildlife. I have chosen the River Dodder as my test site for my thesis. It is an important and beautiful river in County Dublin struggling to cope with the effects of climate change. The River Dodder is critical for rainwater runoff and a much-loved amenity for many Dubliners. Extensive flooding of this river in recent years has given rise to significant environmental and social issues including the destruction and contamination of wildlife and residential homes along its 27km course. (Google Maps, 2019) The thesis aims to illustrate how extensive tree planting and creative landscape development can give more space to allow the River Dodder to flood safely along its course route while enhancing and reinforcing the natural characteristics of the river for both recreation and conservation purposes. Having fully considered the course route of the Dodder I have chosen two sites, one at Old Bawn, Tallaght and the other at Rathfarnham Shopping Centre which I believe with creative landscape development can significantly improve the rivers floodplains and surrounding habitats for the benefit of all. 1 2. INTRODUCTION Thesis Statement: Mitigating against flood risk, biodiversity loss and climate change by restoring the River Dodder’s natural floodplain and habitats. Returning the land to the river and adapting to climate change. Swords Malahide Dunboyne Portmarnock Celbridge Catchment area3 m UBL CO. Bray Study Area Blessington Greystones CLO