Martyna Stefaniak - Studio 4A - Portfolio

PORTFOLIO Martyna Stefaniak

Studio 4A Semester 1 2021

Future of Dublin

Coastal Flood Mitigation

Dublin Flood Map 2050

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Bull Island is a crucial point . It acts as a shield as it protects the area of Clontarf from severe coastal flooding.

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Howth due to it’s high topography is not affected severely . In contrast Sutton is due to disappear back to the sea. Alongside large areas of Dublin : Ballydolye, Ballsbridge and Fairview.

1-Howth Penninsula 2- Bull Island 3- Sutton 4-Portmarnock 5-Fairview 6-Sandymount

Relationship of the River Liffey to the Irish Sea The mouth of the river Liffey is located at Dublin Bay. Therefore it is immensely influenced by the Irish Sea, causing the river Liffey to be a tidal river up as far as Islandbridge.

Sea Level Diagram

Tidal Diagram Tide in

Due to this we often can see when the tide is in or when it is out just by walking along the river Liffey in City Centre. However what are the impacts that the Irish Sea has on the Liffey ?

Current Sea level

River Liffey

Dublin Port

Currently Dublin is elevated 20m above sea level.

Current flooding is mostly from the River Liffey and it’s tributaries. Coastal Flooding is a major concern only during drastic weather conditions.

Irish Sea

As the tide is in River Liffey levels are high showing the impact of the Irish Sea on the Liffey.

Tide out

Future Sea level

The future sea levels in coastal cities will rise.

This is due to the impacts of melting glaciers which is caused by global warming. Resulting in higher sea levels will bring massive devastation economically and ecologically. The river Liffey will be influenced and cause further flooding in the future along with coastal flooding.

River Liffey

Dublin Port

Irish Sea

As the tide is out River Liffey levels are low showing the impact of the Irish Sea on the Liffey.

Current Flood Protection Methods Infrastructure put in place to protect humans from severe flooding can also change the geomorphology, habitat quality and ecology of rivers. Dam construction, water removal and floodplain drainage all impact river communities, as they alter natural river behaviour and limit the connectivity that confers ecological resilience.

This results in biodiversity loss.

Dublin Bay’s average sea level appears to be rising faster than initially forecasted and has risen by twice the global average in the last 20 years.

Newer forms of flood prevention engineering that consider the natural form of rivers could mitigate biodiversity loss, and help to restore habitat and ecosystem function.

Impact of Floods on Biodiversity In some regions, the frequency, intensity, spatial coverage and duration of extreme floods is expected to increase, which could have serious effects on important natural habitats, such as rivers.

Floods have direct impacts on the organisms that inhabit rivers, displacing or killing freshwater wildlife for example. They also have indirect impacts on ecosystems via changes to the shape and form (geomorphology) of the river. The structure of rivers determines the quality and quantity of habitat that is available to freshwater organisms. Therefore, the Structural changes caused by extreme flooding could influence river ecology even more than the direct impact of the flood itself, through changes to habitat availability for example.

River Liffey Flooding Lucan Village 2008

Past Recent Floods -

Dublin City

2nd FEBRUARY 2002 29th NOVEMBER 2009 3rd JANUARY 2014 12th DECEMBER 2015 2nd JANUARY 2016 19th FEBRUARY 2019 31st JULY 2019

Current Irish Sea level

Diagram demonstrating the impact of rising sea levels on the River Liffey Dublin City

Future Irish Sea level

Diagrammatic Sections Demonstrating how different locations in Dublin will be affected by the 10m sea level rise by 2050. current sea level future sea level 10m sea level rise

Dublin City 20m above sea level

Portmarnock 2.5m above sea level

Ben of Howth 171m

Howth Penninsula

Sutton 2m above sea level

Sandymount 4m above sea level

Fairview 3m above sea level

Diagrammatic Sections Demonstrating how different locations in Dublin will be affected by the 10m sea level rise by 2050.

Current sea level Future sea level 10m sea level rise

Dublin City 20m above sea level

Portmarnock 2.5m above sea level

Precedents The precedents I have chosen are relevant under the following topics : 1- The Little Island, NYC

by MNLA Matthews Nielsen Landscape Architects 2- Yanweizhou Park in Jinhua City by Turenscape Landscape Architects 3- Garuda in Jakarta, Indonesia

by KuiperCompagnons

Climate Resilience

Ben of Howth 171m

Howth Penninsula

Water compatability design

Sutton 2m above sea level

Sandymount 4m above sea level

Fairview 3m above sea level

Biodiversity Value Potential Inspiration

The Netherlands This storm surge barrier had to be located in the waterway (Nieuwe Maas – the Scheur – Nieuwe Waterweg) that connects Rotterdam with the North Sea. This played an important role in the planning stage of the construction, as this waterway is the main route to the port of Rotterdam, at that time the world’s largest port.

Therefore, a barrier like the Dutch Oosterscheldekering and the Thames Barrier could not be constructed, as such a barrier would block the shipping route.

Maeslant Barrier (Maeslantkering) , Holland As part of the Room for the River program, the Dutch city of Lent turned a peninsula at a bend in the Waal River into a seasonal island. This provides flood reduction for the main city and enhanced biodiversity.

The Little Island , NYC

-2.4-acre public park -Located on the Hudson River -Provides resilience against climate change.

Little Island is a maritime botanic garden with 35 species of trees, 65 species of shrubs, and 290 varieties of grasses, perennials, vines, and bulbs, many of which have been selected for their fragrance and attractiveness to birds and pollinators.

In this situation the landscape intervention is situated on the Hudson River . It is evident however that it will withstand any flooding.

From observation the structure could also be implemented along a sea , It additionally help to disperse the wave strengths and lower coastal flooding.

Yanweizhou Park in Jinhua City, China

The park sits at the tricky meeting point of three distinct rivers, making flood control a topmost priority. Previously, vast concrete walls were built to stop flood water which turned out to be an eye-sore and disruptive to the marsh-like ecology of the area.

Yanweizhou Park now features great islands of terraced plants which slow flooding down and absorb water. In doing so, the water feeds nutrient-rich silt to the plant life which then grows stronger, elaborating networks of root structures which hold the ground below in place.

The thriving plants bolster the terrace structures and prevent ground erosion. The result is a landscape that irrigates and fertilises itself.

Garuda,Jakarta, Indonesia

The problem is very urgent: because of extreme subsidence a significant part of Jakarta is already below sea level.

Therefore the city faces increasing risk of flooding. Due to the delayed maintenance of the seawalls the water threat for the more than four million inhabitants of North Jakarta will become more and more serious in the coming years.

Jakarta is sinking at an alarming rate of 7,5 (and some parts even with 14) centimetres per year. Without intervention large parts of the city, housing four and a half million people, will be submerged by the sea.

The city will be become water resilient and the new coastal development will house 1.5 to 2 million people.

Effect of coastal flooding without Bull Island With

Coastal Flooding will have a colossal effect on the River Liffey.

Habitats along the river will be lost due to coastal flooding along with damaging Dublin City .

New artificial islands could mitigate future damage from coastal flooding in Dublin .

I propose to create artificial islands in the set locations to mitigate coastal flooding & economic and ecological future potential damage by the River Liffey .This will also be an opportunity to improve water quality & Biodiversity.

My Proposal

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Coastal Flooding Mitigation

The Better Way For Dublin Bay ,

Birdsinbay Island

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Grenville Collins, Map of Dublin Bay, 1693

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18th Century map of Dublin (ca 1760 , showing extensive sand banks at the entrance of the harbour

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Coastal Development Dublin Port, Fairview Park and the Clontarf Promanade are all constructed on reclaimed land from the sea.

Dublin Bay has changed over the years to accommodate to developing needs such as providing port and to combat the issue of ships not reaching the custom house due to high sandbanks forming at the mouth of the River Liffey.

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1816 Taylor’s Environs of Dublin

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1728,Charles Brooking, Dublin Harbour

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1850,Dalkey Quarries

Historic Analysis Of Dublin Bay

1880,view from Pheonix Park

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Views of Dublin Bay from the past

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Dublin Bay, Seabed Analysis Seabed mineral composition diagram

Seabed dredging area diagram

Dublin Bay has a predominant issue of sediment build up.

This is caused by material deposition by the River Liffey as it enters the Irish Sea. This issue is solved by the process of dredging.

Legend Fine Sand Mix (fine and coarse material deposition) Muddy sand Coarse substrate

Seabed dredging graph

The figure below shows how the port has been progressively deepened from about 2m in the early 1800s to its present depth of 7.8m which has been maintained since the 1970s.

Current Issues In Dublin Bay POLLUTION The equivalent of more than 70 Olympic swimming pools of untreated waste water has flowed into Dublin Bay every month over the last four years, according to a report.

Urban wastewater discharges accounted for more than half (54%) of all pollution incidents at beaches around the country in 2020, the EPA report found.

SOS Dublin Bay, an environmental action group, said that its research into data provided

by Irish Water and the four local authorities in Dublin found that 8.875 million cubic metres of untreated sewage and storm waters was discharged into Dublin Bay from 2017 to 2020.

Heavy rainfalls cause waste water overflow from the city’s treatment plant at Ringsend This caused beaches such as Sandymount & Portmarnock to be closed down. With warnings to beaches : Seapoint, Sandycove, The Forty Foot , Killiney and Blackrock which are very popular swimming areas.

Merrion Strand is declassified as a bathing area due to persistent pollution.

Concept Sketch

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Benefits & Purposes

Coastal erosion mitigation

Bird sanctuary

Habitat development

Educational Recreational

Filtration

Coastal flooding mitigation

Multipuprose Vegetation cover Vegetation cover provides many uses. The roots of plants act as an anchor for the soil and sand ,keeping it compact.

The root system stabilises the soil and mitigates wind erosion.

Filtration also takes place in the root system which allows waste water to be treated in a natural process.

Carbon Dioxide is also absorbed which contributes to slowing down gobal warming.

Salt Marsh Benefits

Salt Marshes absorb tidal energy and reduce impact on the coast.

They’re a cheaper and more sustainable way to protect against flooding into the future and they create much needed space for wildlife.

Provide a nesting spot for various bird species.

Maintain a high ecological importance.

Living Shorelines Living shorelines are a green infrastructure technique using native vegetation alone or in combination with low sills to stabilize the shoreline.

Living shorelines provide a natural alternative to ‘hard’ shoreline stabilization methods like rip rap or bulkheads, and provide numerous benefits including nutrient pollution mediation and buffering of shorelines from waves and storms.

Tetrapot Flood Defence It is a symbiosis between artificial and man-made coastal protection. These can be implemented on the verge of the island integrated with vegetation.

These are suggested for rehabilitation and maintenance of Mangroves (group of trees and shrubs that live in the coastal intertidal zone in exotic areas) These however give the perfect opportunity for establishment of habitats through native coastal vegetation.

Habitat Types , Dublin Bay Embryonic shifting dunes

Identifiable zones of both lymegrass Leymus arenarius and sand couch Elytrigia juncea are present, although, as is common with this habitat type, they may be narrow and discontinuous.

(Assigned Poor habitat status in Ireland)

Species in the habitat : Agropyron junceum Anthemis maritima Anthemis tomentosa Elymus farctus Eryngium maritimum Euphorbia peplis Honkenya peploides Leymus arenarius Medicago marina

Salicornia and other annuals colonizing mud and sand Atlantic salt marshes and salt meadows. Formations composed mostly or predominantly of annuals, colonising periodically inundated muds and sands of marine or interior salt marshes.

(Assigned Poor habitat status in Ireland)

Species in the habitat : Bupleurum tenuissimum Cochlearia danica Cressa cretica Cyperus pannonicus Frankenia pulverulenta Hordeum marinum Lepidium latifolium Microcnemum coralloides Parapholis incurva

Annual vegetation of drift lines Formations of annuals or representatives of annuals and perennials, occupying accumulations of drift material and gravel rich in nitrogenous organic matter.

(Assigned Poor habitat status in Ireland)

Species in the habitat : Atriplex glabriuscula Cakile maritima Elymus repens Eryngium maritimum Euphorbia paralias Euphorbia peplis Glaucium flavum Matthiola sinuata Matthiola tricuspidata

Mudflats and sandflats not covered by seawater at low tide Sands and muds of the coasts of the oceans, their connected seas and associated lagoons, not covered by sea water at low tide, usually coated by algae and diatoms. They are of particular importance as feeding grounds for wildlife.

(Assigned Poor habitat status in Ireland)

Species in the habitat : Ulva sp (sea lettuce) Enteromorpha spp Angiosperm: Zostera (eelgrass) Grey Seal (Halichoerus grypus).

Corophium spp Echinocardium cordatum

Coastal Wetlands Habitats Coastal Wetland

Upland Forest

Shrub

Meadow

Lake Marsh

Submergent

Dublin Bay : SPA & Natura 2000 site 1

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Dublin Bay is designated as Natura 2000 site and special area of protection due to it’s immense importance for habitats.

As 1/3 of the bird species are facing extinction the Island has potential to resolve this issue and provide a large habitat that could grow the bird population.

1. Arenaria interpres 2. Branta bernicla 3. Calidris alba 4. Calidris alpina 5. Calidris canutus 6. Charadrius hiaticul 7. Haematopus ostralegus 8. Limosa lapponica 9. Sterna dougallii 10.Sterna hirundo 11. Sterna paradisaea 12. Tringa totanus

Turnstone Brent Goose Sanderling Dunlin Knot Ringed Plover Oystercatcher Bar-tailed Godwit Roseate Tern Common Tern Arctic Tern Redshank

Artificial Island Construction Process 1. A site is chosen

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2. Loose material (top layer of sand ) is dredged to expose hard material (compact sand and mud.

3. A cofferdam is installed into the sea bed which is a construction in in the shape of the designed island which prevents water obstruction.

4. In the cofferdam concrete is poured on the base of the island and on the surrounding sides to provide structure.

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5. A layer of coarse material is added onto the concrete slab.

6. A layer of mixed coarse and fine material is added ontop of the coarse layer. (ie. mixed rocks ,gravel and sand.) Metal rods are inserted to provide structural support for the island.

7. Hydraulic fill is deposited on the bottom layers and a large layer of sand is deposited on top.

8. On the top surface of sand bitumen emulsion is sprayed.

9. A layer of soil is added.

10. Final sand layer is added ontop.

11. Concrete armour units are placed permanently all around the island to protect it from waves.

12. Additional vegetation is planted on the island and it’s embankments to reduce further erosion and provide a stabilising structure to soil beneath.

Rainbowing

Rainbowing is the process in which a dredging ship propels sand that has been claimed from the ocean floor in a high arc to a particular location.

Birdsnbay Island

New Dublin Coast

Constructed Marshland Viewing Point

Woodland Habitat Spot height 2m+ Spot height 3m+ 2.2km Width

Spot height 3m+ Elevated Walkway

Spot height 4m+

Educational Site

6.5km Length

Section A scale 1:15

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Woodland Habitat +2m above sea level

Woodland Habitat +3m above sea level

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Elevated walkway

Woodland Habitat +1m above sea level

Marshland Habitat +1m above sea level

Irish Sea

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Woodland Habitat & Bird Observatory Marshland Habitat

Elevated Walkway & Education Hub

Grassland Habitat Beach

Elevated Walkway Detail

Ledge

Transparent Boundary

Elevated Walkway

Section B scale 1:5

3m Wide

Steel Support

Concrete Foundation

Optimal Habitat Layout

Connectivity

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Coastal Habitat

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Coastal Marshland Coastal Grassland Woodland 4 5 6

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The Island’s topography allows for various habitats to form overtime.

The final point of habitat development will be a forest which will provide a sanctuary for various birds.

The coastal marshland and grassland will provide a food supply as naturally it will house various species of crustaceans and algae.

The highest hill of the island is 6m and the lowest is 1m. During sea level rising the lowest point of the island will be submerged.

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Shelly Banks Beach Seanmoore Park Sandymount Beach Merrion Strand Booterstown Blackrock Seapoint Beach

Visual Impact As the Island is constructed as low-lying and has 4 high points, they act as a frame for the view of Howth.