Nature is Under your Feet_Charlotte van der Woude

n at u r e i s u n d e r yo u r f e e t

n at u r e i s u n d e r yo u t f e e t c h a rlot te van der woude co m mi t tee mirjam koe voe t

( mentor ) /

ma s te r of landsc ape ar chitec ture ac a de m y of ar chitec ture amsterdam j u ly

2019

paul achterber g

/

ricky rijkenber g

from: Architecture without Architects | Bernard Rudolfsky | 1964

p r e fa c e

From ancient times, people and their surrounding were closely connected to each other. When settling down and finding a place to live, man would always find strategic spots in the landscape to build up a home. Topography, water, forest and underground would give people different opportunities in finding a good spot to live, which resulted into a particular use of the surrounding landscape. Finding a start for a settlement came with constraints. Restrictions and chances in terms of resources and climate actually shaped our first settlements, resulting in not only knowledge of the surrounding place, but mainly a sense of belonging and identity.

Today, some of these settlements have changed radically and turned into cities that are ever growing. The connection to their underground and original landscapes becomes more and more blurry and can hardly be experienced. Layers of concrete and asphalt covered the landscape’s rivers and soil. Not only does this affect how people feel and experience the city, but also how our cities respond to current issues like climate change, the degradation of biodiversity and water questions.

As a result of the ever changing city, it seems that we are getting more and more separated from the landscape and that we need to travel far to find ‘nature’. What if we look more carefully at our surrounding? Is nature still present? Isn’t it just covered beneath all these artificial city layers? Is nature closer than we think, and it may be hidden beneath our feet? Can we find opportunity in our original underground landscape? And if so, can we try to implement these hidden structures better into the city?

In order to find an answer to these questions, this project investigates the city of London, where many of its former rivers are now buried beneath layers of concrete. Like many other cities worldwide, these former brooks were the starting point for people to settle down in this region, but because of heavy pollution in the industrial era, these rivers have been turned into underground sewage systems that date back from the Victorian time. This graduation project tries to discover if this linear structure could be a chance to create a ‘new nature’. One that cannot survive the harsh citylife on top, but could facilitate a whole new type of habitat: a fragile nature to be discovered under your feet.

index

4 p r e fa c e

a n e w n at u r e

1

5

t h e c i t y i s yo u r h a b i tat

the river fleet

2

6

w h at l i e s b e n e at h

c r e at i n g m i c r o c l i m at e s

3 lo n d o n a s a c a s e s t u dy

bibliography

t h e c i t y i s yo u r h a b i tat

1

Lost in Movement | Moeys Photography | 2014

t h e c i t y i s yo u r h a b i tat

With approximately 70% of the world population living in cities by the year 2050, it is fair to say that the city has become our habitat. Some people may not even leave the city environment anymore. But how does this city affect us? According to landscape architects Rob Aben and Saskia de Wit, the contemporary cityscape has become shattered. In their book the Enclosed Garden (1999), they describe that the city is made up from different fragments, which form a collage without scale and where it’s hard to find space.

In order to find space and silence, one is always told to go out of the urban environment and escape towards the natural area around. But with cities growing out of their borders more and more, this natural area around the city seems increasingly difficult to reach.

the desire of having nature close by

1

swimming in the River Thames | Alex Voyer | 2017

w h at l i e s b e n e at h

2

from designing the city from top..

..to designing the city from below

w h at l i e s b e n e at h

Since cities worldwide have become bigger and natural areas seem to be further and further away, the time is right to rethink our view towards nature. Is it possible to have a natural experience within the urban environment? As city and nature are mostly seen as two opposite features, the city may also be a chance for a new and unexpected nature: one that is unique and cannot be found outside its city borders.

When looking at the city as a potential habitat, not only for us people to thrive in, but also for nature to take its place, we should start to look at the city from a different perspective. Instead of only looking at the city from a plan drawing or topview, we could look back to its origin and find opportunity in its foundation: the soil and underground. Not only can this foundation mean new chances for nature, it may also cause unexpected and surprising spaces for people, allowing more room for the spontaneous.

drawing belonging to the essay of ‘The Naked City’ Guy DĂŠbord | 1957

2

Stamford Brook entering the River Thames | Paul Talling

When looking more closely to almost every big western city, we can discover a same type of development; where people started to settle along natural structures, during growth and expansion these natural layers got removed, replaced or hidden beneath new citylayers.

For decades, these natural and informal layers got dominated by the ever changing city, but can we also find opportunity in them?

Paris Belfast

Moscow

Bordeaux Kiev

Dublin

Maybe the most obvious former natural structures of current cities, is the water system. In cities worldwide, water was and still is one of the most important factors in building up a settlement. Yet, where water, more specifically rivers, were once the main starting point to building op a home, it also caused issues like floods, pollution and diseases. In numerous Western cities the initial role of the water has changed radically and rivers were canalised or brought underground.

Toronto

Arnhem

London New York

Tokyo

belfast dublin seattle portland waterloo denver

london

antwerp toronto

nashville

mexico city

rivers taken underground worldwide (data not complete)

montreal hartford new york philadelphia baltimore

bordeaux

ar br paris

av

rnhem russels s vienna

vignon

moscow kiev

beijing seoul

tokyo

sydney

a river landscape with side brooks

- a natural river landscape -

When diving more into how cities have developed over time, we can see that all of our current cities have their own natural starting point. This case study focuses on the settlement along the riverbed.

The natural landscape consists out of a river landscape with a large main river coming from higher ground and flowing towards the sea or a bigger water plane. From mostly all directions smaller side streams and brooks can be found, coming from natural springs located on higher ground.

- a natural river landscape -

occupation along the side brooks

- occupation along the side rivers -

Since fresh water meant life, food and eventually transportation and energy, the river landscape seemed like a perfect place to settle down. First occupations in this typology are mostly found along the smaller side brooks, where the higher ground was more safe than along the lower valley along the main river. Here, people still had access to the water for washing, fishing and sailing and were safe at the same time. Next to this, the water also had a holy and spiritual meaning. In a lot of settlements, churches, wells and other holy places are found in the former river valleys.

- a natural river landscape -

- occupation along the side rivers -

industrial use of the water: canalisation

- industrialisation and canalisation -

With a growing population and the start of the industrial era in the 18th century, small settlements began to grow bigger and needed to adapt to this change. The side brooks began to have a different meaning and were mostly canalised into straight waterways that were easier to sail upon. This caused the natural edges of the brooks to change into straight riverbanks.

Next to this, the streams were mostly misused as a gutter. Garbage from households and polluted industries were thrown into the water, flowing through the whole city and ending up in the main river. In many cities this pollution not only caused a terrible smell, but also many contagious diseases like Cholera.

Where water was once the vital starting point for a settlement, in many cases it turned into an enemy of the growing city.

- occupation along the side rivers -

- industrialisation and canalisation -

covered streams with the city on top

- covered rivers in an urban setting -

In the current metropolis city, the negative side effects of the rivers took over their positive meaning. In the centre of many big cities, side rivers and brooks have been put underground. Most current sewage systems of these cities still depend on the former rivers for their water system, which mostly date back to Victorian time. The water is in many cases still flowing as an invisible living system underneath the surface of the city.

Although the water may have been lost within the city on eye-level, putting these rivers underground also brought welfare and quality to the city of today. Due to putting these brooks away, cities became more healthy and less polluted.

discovery of the Fleet Sewer | sub-urban.com

discovery of a cave | Robbie Shone

Coming back to the question: if ‘nature is closer than we think’, these former river structures show that there is still life flowing beneath the current city.

The sewers are currently creating a mysterious underground system that is a memory of the city’s origin and growth. Here, nature is literally beneath your feet, which creates an extremely exciting story underneath the daily city life.

In this informal underground network, people are already seeking for adventure. What some people would seek for in the outside landscape, others are exploring within the cityscape. The old rivers are providing an alternative network that gives opportunity to discover exciting spaces and escape the strict city life above.

Voyage au Centre de la Terre | Jules Verne | 1864 illustration by Edouard Riou

In most literature the underworld is generally referred to as something evil, dark and dangerous, but Salomon Kroonenberg is one of the few writers that sees the beauty of this undiscovered world. Where most people are focused on discovering the universe and the sky on top of us, Kroonenberg is trying to grasp the earth beneath our feet in the same order.

In his book ‘Why Hell Stinks of Sulfur: Mythology and Geology of the Underworld’, he shows that we shouldn’t only see the underground as a mine for natural resources, a place to hide garbage or as a last resort for the death, but mainly as an irreplaceable archive and infinite source for mythical stories. He views the inside of the earth as a beautiful living ecosystem that we have only recently began to discover.

The Divine Comedy | Dante Alighieri | 1480 the Abyss of Hell

‘Evolution has not given us eyes that allow us to see through rock ... If the earth was transparant, like a giant glass marble, they would spend all day lying flat on their stomachs and looking down at all the activity below them.’ - Salomon Kroonenberg -

Why Hell Stinks of Sulfur: Mythology and Geology of the Underworld

- covered rivers in an urban setting -

a chance for a new nature?

- a potential new nature -

The underground sewers could mean great opportunity in reconnecting the city with its former landscape. But in order to respect its current quality as hidden and mysterious structure, simply revealing and daylighting these former rivers would not do justice to them. Can we see these hidden structures as places where we create, rather than reveal?

Next to this, these spaces could also give great opportunity in dealing with contemporary issues, such as water shortage, floods and pollution, but also the degradation of biodiversity. Finding solutions for these issues could greatly be implemented within this question, causing not only more surprising spaces for people, but as well places where nature takes its place.

lo n d o n a s a c a s e s t u dy

3

lo n d o n a s a c a s e s t u dy

3

rivers turned into underground sewers shown in red

bookcover from: The Hidden Landscape | Richard Fortey | 2010

As a location for this graduation project, the city of London is chosen as a case study. London is one of the many cities found worldwide that lost a fairly amount of its former rivers. Twelve of the former side streams of the Thames are now hidden underground, beneath layers of newly developed city.

Although in the city centre of London all of its former rivers are put underground, they were once the starting point for the city to develop. The first settlements of London or Londinium are found along the small stream of the Walbrook, but also along the banks of the river Westbourne, the river Fleet and later on the south bank along the river Effra settlements were rapidly spreading.

development of the River Fleet

St. Pancras Old Church along the Fleet | 1815

a canalized Fleet: ditch | Âą 1840

The area around the river Thames could be seen as a collection of smaller settlements, all connected to the water streams that eventually flowed into the river Thames. The open spaces in between these smaller settlements or villages are in a later period covered up by urban development and industries. Yet if you look carefully, the origin of the side streams of the Thames can still be discovered all around the city of London.

The development of these side streams could be generally explained: where small settlements started to appear along the riverbanks, they grew into large urban areas with large industries and canalised streams. When pollution took over, these channels were taken underground.

covering the Fleet | 1845

Fleet Sewer | 2010

from: The Lost Rivers of London | N.J. Barton | 1992

a n e w n at u r e

4

discovery of rare fern species in the citypits of Utrecht Wim Vuik | 2007

a n e w n at u r e

When looking at the underground sewers as an opportunity for nature, it is important to realise that the former river as flowing and meandering structure can never be restored. For more than two decades, the characteristics of the former river landscape are lost.

Besides, the current underground network has its own qualities that should be protected and respected. The London sewage system dates back to Victorian time and is completely made out of local brickwork that shows impressive engineering work. What type of nature could be possible, without losing the quality of this underground brick network?

As a reference, around the year 2007, Wim Vuik discovered numerous of endangered species of ferns underneath the streets of Utrecht. By investigating all the city pits, a complete hidden floral layer was found.

This discovery shows how structures made by people, could be unexpected places for a new nature. One that cannot survive the harsh citylife on top, but could facilitate a whole new fragile type of habitat: a nature to be discovered under your feet.

4

‘under the paving, lies the beach’ | graffiti on a wall in Paris | 1968

civilisation d-zone #3 | Gioberto Noro Photography | 2007

In order to give answer to the question what this new nature could be, it is important to define what are the key elements that could lead to a natural experience. At first sight, nature seems to be something that is bigger than us humans and transcends our own point of views. But when looking more closely, a natural experience may not be about scale.

The following three criteria will define my approach towards nature throughout this project:

1. nature as the unexpected

Where our man-made world is completely invented and carefully thought out, nature goes its own way and may appear at unexpected moments, leaving you in a state of wonder and awe.

2. nature as a bigger whole

A natural experience can make sure we feel that we are part of a bigger network.

3. nature as an uncontrollable force

Maybe the most important factor about nature could be the realization that we, as humans, cannot control everything around us.

‘Meer nog dan de kunst, raakt de mens geraakt door de schoonheid van de natuur. We zijn betoverd door de kleuren van de ondergaande zon, juist omdat we die niet kunnen sturen.

Geheel autonoom bepaalt zij haar haar kleur. Op het moment dat de mens zou kunnen beslissen dat de zon een tikkeltje rozer zou moeten, is deze betovering verdwenen. ... Juist omdat we haar niet kunnen beïnvloeden, trekt de schoonheid van de zon zo zeer.’

- Bram van de Klundert Expeditie Wildernis

handsketches of a possible underworld

the river fleet

5

N

the river fleet

5

former course of the River Fleet in bold red

Farringdon Street covering the former Fleet valley | 2018

After analysing the different former rivers in London on the scale of the complete city, the former river Fleet is chosen as a case study to zoom in.

The river Fleet used to be the biggest side river of the Thames and the topography of the valley is still very well visible in the inner city. The current sewer still flows into the part of the Thames where we can find brackish water, due to the tidal flow of the Thames estuary. The salinity of the water could be an important quality for the new nature within the sewer.

sweet water

One could say that the Fleet is representative for all the other hidden rivers in London, since a lot of typical urban aspects that used to be connected to the water, can still be found along this former line. Like many other former rivers found in London, the Fleet consists of two sources that join together in a former village, crosses one of the oldest churches in London, flows along the river terrace of the Thames, continues its way within the depth of the valley and flows out into the Thames.

brackish water - Battersea -

salt water - Gravesend -

N 0

500 m.

Hampstead Heath | river source representative for other sources

Kentish Town | river joint representative for other joints

St. Pancras Old Church | holy river representative for other religious places

Ray Street | river terrace

representative for other transition areas

Holborn Viaduct | river valley

representative for other valley crossings

Blackfriars | river outlet

representative for other outlets to the main river

In order to transform the current sewage into a place where nature can take its place, it is crucial to be able to add daylight. However, completely opening up the hidden structure would not do justice to its current qualities.

In order to respect the current brick structure and enhance the mysterious quality of the underground network, the idea is to pick specific spots along the linear route where small openings can be made.

They will function as windows towards an underground new nature, each containing their own specific conditions for a unique and hidden habitat. On each spot, a new and fragile nature can develop. One that cannot survive the harsh citylife on top, but which is protected through its location within the foundation of the city.

The chosen spots along the route are representative to other spots that can also be found along other hidden rivers around London. They represent places that are still present in the urban environment, but used to be strongly connected to the old river.

creating windows to an underground new nature each spot containing specific conditions for a unique habitat

At the start of the network there are the two main sources of the Fleet, that are still open to the surface, found at the natural area of Hampstead Heath.

After leaving this area, the water disappears underground.

The first subterranean spot is located in Kentish Town, where the two tributaries of the river joined together in a former village that is now attached to the rest of the city of London. Later, the water passes one of the oldest churches of London: St. Pancras Old Church and its former well.

On this location, the water used to have a holy and spiritual meaning. The network continues towards Ray Street, where not only the city on top but also the underground sewage jumps down 1 meter because of the deposits of the river terrace of the Thames. After a strong curve, the water continues to flow in a straight line underneath Holborn Viaduct, which crosses the entire Fleet valley and connects different city levels with each other. Finally, the Fleet flows out into the tidal river Thames. In between the different spots, the underground network continues to be connected from source to outlet.

river joint

holy river

river source

100 m

sand | gravel london clay | impermeable chalk | water bearing bedrock | impermeable

river source

river joint | -1.5 m.

holy river | -3 m.

river outlet river terrace

river valley

Âą 10 km. or 2 hours walking

river terrace | -4 /-5 m.

river valley | -6 m.

river outlet | -7 m.

river source

river valley

river joint

river outlet

holy river

river outlet

river terrace

river outlet

the current watersystem of the Fleet Sewer: a combined system

source and rainwater wastewater intercepting sewers thames tideway tunnel

The first step to create a new nature within the underground system, is to clean the sewage and separate the current mixed water system.

The current sewage system of London dates back from Victorian time and mixes source and rain water with water coming from households, industries and companies all together in the same sewer. For a long time this combined water flowed directly into the river Thames. Until around 1856, when the intercepting sewerplan of Joseph Bazalgette made sure the underground drains didn’t run off directly into the Thames anymore, but were interrupted with three main sewage lines perpendicular along the Thames. The water was brought east, where two large water treatment centres cleaned the water, before running off into the main river.

Despite this ingenious system, during heavy rainfall the capacity of the intercepting sewers is not enough, causing polluted water to still run off into the Thames. Next to this, the plan of Bazalgette was build for a city of 6 million people. London has a current population of 8.1 million people and is still counting. Next to the fact that our climate is changing and rainfall increases, the city of London decided to build an additional ‘supersewer’ (or the Thames Tideway Tunnel) underneath the river Thames, where all the water from the city, including rainwater, won’t have direct contact towards the river Thames anymore.

Bazalgette: Intercepting Sewerplan in yellow (1856) combined with the Thames Tideway Tunnel in purple (2018 - 2020)

the future watersystem of the Fleet Sewer: a seperated system

wastewater and intercepting sewers

water from the source, rain and Thames

This project accepts the current plans of the city of London, but also proposes an additional approach. The water from, in this case the Fleet sewer, will be separated into clean source and rain water, and polluted water from households and industries.

In order to achieve this, two additional drains will be added inside the main Fleet sewer, to collect the polluted water coming from side drains that are connected to households and industries. The two additional drains will eventually flow out into the Thames Tideway Tunnel and the former Fleet sewer can remain its contact to the river Thames.

The central part of the Fleet sewer stays intact and will only contain water from the source, rain and water from the Thames during high tide. During heavy rainfall and high tide at the same moment, the door will close again and the system will run off into the Thames Tideway Tunnel.

reference of a seperated sewage system underneath Antwerp adding side drains within the historical network

c r e at i n g m i c r o c l i m at e s

6

river source

|

h a m p s t e a d h e at h

open views in the fields

enclosed views along the source

area part of a former estate (maintained)

source water flowing into ponds or sewers

N

0

20 m.

Although the water within the urban area is taken underground, the initial sources of the streams can hardly be removed. At the start of the Fleet sewer there are the two main sources of the former river that are still open to the surface and remain intact. They can be found at the natural area of Hampstead Heath, a former estate that is now open for the public, and is still a large natural recreative area close to the city of London.

The soil of this area contains of sand and gravel that lies on top of the London clay. This permeable layer was once blown here with the wind and it has the effect that many small springs and sources can be found here. Most of the time, these sources are located within pieces of small forests, located on lower parts of the area, in between open, higher grass fields that are maintained in a structural manner.

Despite the natural character of Hampstead Heath, due of its history as an estate, the area still has a strong maintained character and its ecology around the sources could be strengthened. By enhancing the existing vegetation by enriching the underground soil, new chances for lower levels of vegetation can occur. By adding a few humble bridges across the small streams and connected to the existing path system, visitors can experience the contrast between the open grass fields and the dense forest around the source.

Moorhen

Mentha aquatica

Veronica beccabunga Robin

Myosotis scorpioides Emperor Dragonfly

Lysimachia vulgaris

Chr ysosplenium oppositifolium

Filipendula ulmaria Caltha palustris Mayfly

The river sources in Hampstead Heath are currently providing the native habitat of the water source forests, with species such as Fagus sylvatica, Quercus robur and Alnus glutinosa. Shrub layers consist mainly out of Ilex and Sorbus.

The small forests around the sources could be strengthened by enriching the vegetation in the shrub and herb layers. By replacing soil fragments from other, comparable situations, the soil could be enriched which increases soil life and biodiversity. The same could go for taking out and spread seeds out of valuable and healthy trees elsewhere. Doing so, this will also strengthen the area as a contrasting edge in relation the open grass fields further uphill.

The chalk-rich source water, together with enriched soil fragments, could attract new vegetation consisting out of Mentha aquatica, Veronica beccabunga or Lysimachia vulgaris. Throughout all the seasons, different species of plants can flower and would mainly attract singing birds like robin, but as well moorhens and dragonflies.

river joint

|

kentish town

? ?

existing park divided into two parts

existing park part of a historical settlement structure

key element to the space is the brick railway arch

collecting water from surrounding directions due to topography

N

0

20 m.

After the source, the first window is projected in Kentish Town, which used to be the place where the two tributaries of the former Fleet river joined into one main stream. This can still be noticed from the current topography of the area, since it collects water from all different directions, except the southern one. The greenspace in the middle of this junction, called Camden Gardens, connects three historical streets together and as well connects the former village area towards the city centre of London, south of this area.

At the same time, the garden is cut into two pieces due to a brick railway arch, dating back to the end of the 19th century. The arch plays a key element in the garden, not only because of its scale and craft of brickwork, but also because of its lost function as a railway connection. The city of London already has plans to redevelop the upper part of the bridge into a linear park structure, connecting not only different neighbourhoods with each other but different city levels as well. Adding an underground lower level to this plan could strengthen these ideas, and at the same time reactivate the current Camden Gardens as a meeting spot in a dense district.

By introducing a new, lower level along the westside of the garden, a connection can be made from Camden Gardens towards the underground sewer. Since the sewer is only 1.5 m. deep at this point, this edge can have a gentle slope from high to low. The existing vegetation of the garden can remain largely intact, only the new, long stretched edge will create an additional green border of the space. A floating and transparent pathway will connect a new route, where visitors can experience the underground network when slightly looking down, being surrounded by this new edge.

Butomus umbellatus Lythrum salicaria

Typha angustifolia Common Newt

Alnus glutinosa Sedge Warbler

Common Frog Iris pseudacorus

Salix myrsinifolia

Sparganium erectum

Alisma plantago-aquatica

Since the existing greenspace of Camden Gardens mainly consists out of a big tree layer, lower levels of vegetation are currently missing. By adding a valuable wet fringe to the existing trees, Camden Gardens will be increasingly diverse in its biodiversity.

Because of the gentle slope connecting Camden Gardens towards the underground network, the edge can provide a gradient of riparian vegetation, covering the edge from high to low. On the path along the edge, visitors can walk in between the reed-like vegetation. At the same time, the water coming from different directions of the garden will be filtered, before entering the underground watersystem.

Species such as Phragmites australis and Butomus umbellatus are joined with bigger shrubs and trees such as Alnus and Salix. Amphibians such as frogs and salamanders can be found her, but also birds that make use of the reed can find their place.

The section on the left shows the new edge along Camden Gardens, connecting the underground watersystem with the city on top. The gentle slope is providing chances for a new nature on different levels, creating a gradient of different vegetation depending on the water level. Due to lowering the edge of the garden, a part of the foundation of the brick railway arch is revealed. Next to this, a new brick wall will be made in order to separate the floating wooden pathway from the street on top, which also provides a growing habitat for plantspecies that will grow within cracks in the wall.

Not only can the underground network be experienced from the pathway on the lower level, a new staircase connecting the upper side of the railway arch also provides a viewpoint downwards. Here, visitors will also have a belvedere across the complete Fleet valley going south, which gives a well understanding of the former river system. Next to this viewpoint, the water flowing from different directions is made visible on the regular level on the city. By doing so, the different urban levels are reconnected with each other, providing new exciting spaces for people, as well as a new habitat for flora and fauna.

h o ly r i v e r

|

s t . pa n c r a s o l d c h u r c h

church and cemetary located on higher ground

cemetary completely fenced H

H

school

Created by Alexander Panasovsky from the Noun Project

school

location is facing the backside of the railway station

former well was located on the southern edge of the cemetary

N

0

20 m.

The second window downwards will be located along one of the most ancient sites of Christian worship: St. Pancras Old Church. The site may even date back as far as the early fourth century, but the church itself had a lot of renovation since then. St. Pancras used to be located on the banks of the river Fleet, facing the holy water with its entrance and was surrounded by a historical cemetery. Both of them are still located on a higher part of the area, due to floodings from the Fleet in earlier times. Further south, there used to be a former well bringing fresh water to the surface.

Because of the expansion of the railway lines east of the church, a big part of the cemetery has been removed around the 1860’s. South of the site, the current International railway station (also called St. Pancras) can be found and today, the church and its cemetery feel like a backside to this station.

By rethinking this backside and redefining the edge of the railway tracks, the pedestrian route from and to the station of St. Pancras can be highly improved.

To achieve this, a new route is made along the existing young birch forest that grew recently along the edge of the railway. This safe and logic sidewalk will eventually pass by the location of the former well and goes on into a new staircase connecting the cemetery with this former holy place. The new staircase continues down towards the level of the underground network, where the former holy meaning of the water well can be experienced from below, creating a contemporary spiritual place.

Chaffinch

Par thenocissus quinquefolia

Hedera helix

Squirrel

Betula alba

Great Tit Clematis vitalba

Asplenium scolopendrium

The location of the former well and the current underground water system are parallel to a young birch forest that spontaneously grew along the train tracks. By carefully and selectively cutting some of the existing trees, the forest succession can be enhanced, allowing understory to develop in the shade of the remaining pioneer trees. Plants such as Hedera and Clematis can develop in this understory.

By making a cut on the location of the former well, that goes down towards the underground waterstructure, the forest with its groundcover vegetation can grow further into this newly made space. Doing so, the climbing plants are able to grow over the newly built walls on the eastern side of the new space. On western side of the newly made staircase, place will be reserved for one big birch tree, in order for this space to become part of the small forest.

Here, the sewer is approximately 3 meters deep underground, resulting into a quiet place, away from urban noise. At the same time, the space keeps its contact towards St. Pancras Old Church. A carefully defined opening, right on top of the seating element, will allow light to enter and to enhance the spiritual meaning by connecting the space towards the sky.

river terrace

|

r ay s t r e e t

current street shape still following the former river curve

buildings in a stony environment 18.00 - 08.00high h 08.00 - 18.00 h

18.00 - 08.00 h

08.00 - 18.00 h

transition area from high to low

sound of falling water still present

N

0

20 m.

As a third window, the transition area of Ray Street is chosen. Here, the former Fleet river made a strong curve that is still noticeable in the shape of the current street. The curve also indicates the spot where the river terrace of the Thames begins, resulting in a sudden change in level of about 1 meter difference. Not only can this level difference be seen within Ray Street, one can also hear the water of the Fleet sewer falling down on the same spot.

The area around Ray Street can be seen as highly urban, with large office buildings of mostly 6 floors high and almost no greenspace in the public space around these high buildings. On warm summerdays, this area can be 6 degrees warmer than the surrounding outside landscape of London, resulting into one of the many heat islands that can be found in the city centre.

To create a cooled down spot, this intervention makes use of the water falling down 1 meter. A long-stretched incision is proposed, enhancing the existing curve. This crack will connect the underground water network with the city on top and will facilitate a new wall, functioning as a green edge in between the road and the sidewalk.

Ranunculus aquatilis

Asplenium scolopendrium

Dr yopteris filix-mas 7-Spot Ladybird

Asplenium ruta-muraria

Tor tula muralis

Noble Chafer

Potamogeton lucens

Bloody Nosed Beetle

Cymbalaria muralis

Polytrichum commune

The new wall that guides the curved opening, will be facing north and therefore can contain a shadow and wet biotope. Numerous fern species such as Dryopteris and Asplenium can find their place in the terraced wall.

Different types of moss species or wallplants such a Cymbalaria can settle well on this location.

Ferns and moss species don’t usually flower, so fauna species will mainly consist out of insect types such as beetles, ants and ladybirds.

The section on the left shows the newly built walls that connect the underground watersystem with the city on top. Because of the difference in level, water is splashed up towards the surface creating mist to cool down the surrounding are during hot summer days.

Throughout the year, the sound of the water falling down 1 meter can be heard in Ray Street and can even be stronger on days when rainfall is heavy.

r i v e r va l l e y

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holborn viaduct

historical bridge crossing the Fleet valley

transitions from high to low

wide view across the Fleet valley

N

0

20 m.

The next window is located at Holborn Viaduct, which is a long bridge that connects the west side of the Fleet valley to the east side. On top of the viaduct one can have an impressive view towards the river Thames. As a central element of the bridge, the red Holborn Viaduct is located with four connecting bridge houses. These bridge houses are all containing public staircases, bringing pedestrians from the lower level of the valley up to the level of the bridge. Next to these staircases, the bridge houses contain some small offices and shops but are also partly vacant.

In order to reconnect the valley to the water, one of the vacant bridge houses is used to make a link between the level of the bridge, the level of the valley and the level of the water. The rooftop will be partially removed, opening up the building to the sky, creating a vertical connection that faces all the different layers of the city.

Betula alba

Daubenton’s Bat

Pseudofumaria lutea

Common Swift

Black Redstar t

The vertical wall can be an outstanding spot for all different types of bird species that like to breed in a rock-type environment. Species such as the common swift and the black redstart would easily thrive here. On some parts of the wall, pioneer vegetation can occur such as small birch trees.

Since the underground sewer is almost 6 meters below street level here, there is a great opportunity in opening up a part of the underground space as well. This opening will connect the high wall and existing staircases with the underground water system and will function at the same time as a bat cave. The newly made walls can all be implemented with holes and incisions of different sizes, creating a broad habitat for numerous bird species.

On the section on the left, the intervention is showing the opened up building with the new wall, with on a lower level the small extension of the existing staircase to watch the newly built bat cave.

The exterior of the bridge house will remain completely intact, making sure the ensemble of Holborn Viaduct won’t be touched. Inside the house, new pieces of wall will be added in front of the existing interior wall, housing breeding spots for birds and other flying animal species.

On a lower level, the existing staircase will be extended a little further, in order to let people watch the newly built dome made for bats.

river outlet

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blackfriars

multi-layered space: roads, pedestrian tunnels, sewers and metro

current infrastructural node

? ? unclear entrance to Blackfriars Station

?

Thames as a tidal river

N

0

20 m.

The final window is located at Blackfriars, where the river Fleet used to meet the river Thames. A large area of this location used to be part of the ‘strand’ or a small estuary, but in order to protect the city from the tidal river Thames, the Victoria Embankment was built and turned the natural shore into a stony one. Still, some old relics can be found from this time, such at the old building of the Black Friars Pub, that used to be located at the edge of the shore. Also, one of the former bridge heads of Blackfriars Bridge remains standing as a silent witness in the middle of the embankment.

The area today consists of a complicated infrastructural junction, of multilayered flows of cars, pedestrians, bicycles, water, metro and trainlines. The metro and trainlines join together at Blackfriars station, in which the current entrance is unclear and messy with no clear space to walk and cross over the big roads. Luckily, the city of London has plans to downgrade this junction of car traffic with one lane, creating room for a slower public space.

By having cleaned the watersystem of the sewer, the first act will be to open up the doors towards the river Thames, reconnecting the two water flows.

Because of the complexity of this location, the next approach will be to redefine the infrastructural network and to improve the pedestrian routing of the space. The underground waternetwork is used as a starting point; the public space on top will follow. Doing so, this results into a wide pedestrian boulevard, connecting the entrance of Blackfriars station to Blackfriars Bridge, continuing across the southbank of the river Thames.

Rainbow Trout

Lemna minor Lythrum salicaria

Populus alba

Cotula coronopifolia

Rockpool Prawn Veronica catenata

Mitten Crab

Door Snail Vaucheria marina Hieracium murorum

The new pedestrian network created on top of the underground watersystem gives opportunities to make connections from the city on top to down below. The sewer is located around 7 meters underground and three independent spots are chosen to connect the underground watersystem to the different infrastructural layers of the site.

The first one will connect the watersystem with an underground pedestrian tunnel and metroline. The second one will connect Blackfriars Bridge to the underground and strengthen the location of the former bridgehead. The third spot will reconnect the Thames Embankment to the outlet of the river.

All of the three spots will be re-joined with the Thames and will therefore be under the influence of the tides. Around this area of the river Thames, the water is brackish and this level of salinity could mean special vegetation such as Lemna minor or Veronica catenata. As for tree species, one of the few trees that can handle salt water is Populus alba. Two times a day the water will go up and down, also bringing water animals such as fish, mitten crabs and mussels along with the water. Tidal nature can be experienced from within the urban fabric.

On the section below, the three incisions towards the underground network can be seen, each one of them connecting a different layer of the city. On every spot, daylight, vertical and diagonal walls are introduced, in order to give space for vegetation to grow and for animals to settle.

The section is showing the situation during high tide, in which in every spot the level of the water will be close to your feet. Especially at the final spot under the bridge, visitors can almost dip their toes into the Thames during high tide.

In case of emergency, when it’s raining really hard and the Thames is having high tide, the in between doors will close off and the water inside the underground network will overflow into the Thames Tideway Tunnel. On other situations, the door towards the Thames can stay open.

103.85 high water

97.35 low water

the topwall will be finished off with glazed bricks to keep it free of vegetation

London Stock Bricks made from local clay water level during high tide

plants such as these brass buttons can root well in the joint made of chalk cement Populus alba can handle the salinity of the river Thames

mitten crabs can find shelter in the textured bricks

glazed brick showing the transition between old and new walls

existing brick wall of Fleet Sewer

water level during low tide

fish from river Thames are able to swim upstream

bibliography

&

c o lo f o n

The london rivers action plan A tool to help restore rivers for people and nature

January 2009 www.therrc.co.uk/lrap.php

bibliography

&

c o lo f o n

This graduation project would not have been possible without the following people and I’m very grateful to have done this together.

Committee - Mirjam Koevoet - mentor - Paul Achterberg - additional member - Ricky Rijkenberg - additional member Experts - Salomon Kroonenberg - geologist and writer - Marco Roos - botanist and researcher biodiversity discovery - Paul Holden - owner guerrilla exploring - Paul Talling - writer and city guide - Stichting NH-Bos Friends, family and colleagues - Jean-François Gauthier - Kristel Brouwers - Carlijn Klomp - Frank Vonk - Gerdi Reukers - Nico van der Woude - Willian Vonk - de Beer - Koen van Hoof - Simon Wijrdeman - Roeland Meek - Leo Taylor and Naomi - Ruud Dubbeld - Lisan van der Wielen - Han Thijssen - Niké van Keulen - Sebastian Vervuurt - Nathan Kok Head of Landscape Architecture - Maike van Stiphout - Hanneke Kijne

e p i lo g u e

Throughout this project, I have created six windows on the former river Fleet. The project defines six interventions, creating conditions for a new nature to develop right under our feet. A nature that could not survive the harsh citylife on top, but is able to flourish within the hidden structure of the sewer.

On one hand, the design choices that are made, aim to be site-specific and respect the historical and contemporary issues surrounding a certain place. On every selected spot, cuts into the existing urban fabric are chosen carefully in order te let nature grow and to be beneficial for local inhabitants.

On the other hand, one could see the tools that are defined and the solutions that are proposed as exemplary for similar projects for other hidden rivers in London. The chosen locations can be found along many other former rivers; from the source to the outlet, comparable situations as the one described along the former river Fleet are visible in London.

These typologies could even be found in other cities worldwide that have developed in the same way.

Following interventions could easily be imagined. On a bigger scale, a whole new green landscape could be developed for the London metropolis.

It would form a completely new layer in the green network of the capital, based on water as the structural element as well on islands, for highly precious and rare habitats.

On a broader scale, the project shows a new approach towards urban design.

As explained earlier, it is time to look at the city from its underground layers instead of the classical top down approach.

This graduation project is a plea to value, protect and enhance this hidden world. It is a place for the unexpected, a place that we cannot control fully and a place where we as humans, are only a guest. In other words, a place where nature takes its place.

n at u r e i s u n d e r yo u t f e e t c h a rlot te van der woude co m mi t tee mirjam koe voe t

( mentor ) /

ma s te r of landsc ape ar chitec ture ac a de m y of ar chitec ture amsterdam j u ly

2019

paul achterber g

/

ricky rijkenber g