Nativescaping Resilient adaptation for Perth, WA Caterina Poncemi
Nativescaping Resilient adaptation Perth, WA. Senior Thesis in Architecture Academic year 2017/2018 Thesis Advisor: Luca Emanueli Co-advisors: Stephen Gibson, Vittoria Mencarini work of Caterina Poncemi
Alla mia mamma e al mio papĂ , che hanno cresciuto tre figli felici. Ai miei fratelli, a tutta la mia famiglia e agli altri animali.
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Summary Introduction 9 Abstract 11 Arcadialand: the british colonial landscape
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Suburbia: the settlement
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Waterbills: the water footprint of green spaces
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Hard times: drought and desertification
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Welcome to Perth: case study analysis
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Drought and Mean Sea Level Rising: a resilient strategy
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Design proposal: Leeve Park, a new urban leeve
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Nativescaping: the Narrows, extensive xeric landscape
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The Swan Coastal Plain Cultural Roots Landscape after the Colony White Australia
Exponential growth Second generation Pioneers The Town Planning Development Act The Metropolitan Regional Plan Suburbia, the Result Desire for density
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Footprints 33 Drinking water 34 Demographic projections Desertification The water rush High tide
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Introduction 49 Original vegetation 49 Geology and reclamation 50 Public Open Spaces 51 Low-lying and vulnerable 59 Counter-proposal 60 Garden/garden 61 Analysis 67 Terrace road 68 The Leeve 68 Heirisson Islands 69 Analysis 75 Wildflowers 75 Net saving 76
Conclusions 83 Bibliography 87 Credits 91 Graphics 93 7
Introduction
Economical and developing choices made until the ‘80 caused an unprecedented environmental change. What has been done cannot be changed, but what is going to happen from now on is everybody’s responsability.Coping with climate change can be frightening or frustrating, but denying it will not make it disappear. We are in front of a crysis that questions the supremacy of human kind above nature: we have to study, research and take action in order to synthesize a new development direction and we have today the knowledge and the technology to do that. We all have to remember that future doesn’t happen, but has to be designed. Everybody should act accordingly, myself included.
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Abstract
The landscape of Perth, Western Australia, is dominated by lawns and exotic trees, in strong juxtaposition with the native landscape and the arid climate. The extent of the metro area of the capital make this phenomenon of landscaping colonialism a thread for the Swan Coastal Plain biodiversity and for the unreliable water supplies. The quick demographic growth and the climate change forecasted put the settlement in danger of desertification and Perth could become the first 21th century ghost capital. In this context, it’s important to encourage a change in the landscaping aesthetics starting from the Central Business District of the metro region, re-drawing the link between City of Perth and Perth Water, moving back the coastal infrastructure in order to accomodate the tide and allowing -partially- the restoration of the tidal ecosystem of the pre-colonial era. The waterfront of the north shore is redrawn from a functional leeve that protects the CBD, dividing the dry, useable park at the feet of the buildings and the wetlands of the foreshore. The design of the park includes the revegetation of Heirisson island, where the tide are accomodated in a canal system: this new landscape has an educational porpouse and will recall the sandy shallows that used to link the two shores of the river. Finally, to supplement the new design of Perth Water foreshores, the highly infrastructured area of Mounts Bay is replanted with traditional bushland vegetation and a botanic exposition of xeric australian wildflowers, underlining the beauty of this arid landscape. Accordingly to the extended bushland in Kings Park, the junction becomes a native landscape that characterize the entrance in the City in order to give Perth, finally, a sense of place.
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Chapter 1
Arcadialand
Landscape in Perth, WA, is exotic.
The Swan Coastal Plain
Perth, capital of the state of Western Australia, is now a metrocity founded in 1829 by the British Empire on the Western coast of the continent. Before the European Settlers, the Aboriginal people have been the keepers of this land for more than 40’000 years. The landscape that layed in front of the early settlers was much different from what they were used to in their native England. Steering into the Swan river, they found a system of wetlands (fig. 1) and tidal marshes carving its way through the woodland. The sandy plain was covered in Banksia forest all the way to the Darling Scarp, interrupted only by Eucalyptus forest ( fig. 2). The Noongar people were occupying the land, hunting and fishing on the shores of the river estuary. They were nomadic and they used to modify the landscape through controlled fires; these clearings where hunting grounds (fig. 3).This ecosystem, the Swan Coastal Plain,is in fact part of one of the 35 biodiversity hotspots in the world and used to be extremely vary and rich. With the colonization, this ecosystem and the millenial culture of Noongar people had suffered huge transformation due to the very quick urbanisation. Today, 93% of the native vegetation and the 80% of the wetlands has gone due to urban pressure1. The bushland has almost completely disappeared to make room for the evergrowing city; some relevant bits are saved, as in the case of Kings and Bold Park, and some other fragmented remnants.
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Landscape after the Colony
In public open spaces, as much as in private gardens, manicured lawns have took the place of the bushland and remind the parks of the old England. Gardens and parks are full of roses, mango trees and frangipani; chartacterized by lawns, tropical trees and flowering bushes, it recalls the Arcadia ideal landscape, but with a sort of taste for the exotic (fig. 3, fig. 4). Today, this landscape aesthetic has led people beauty perception to the point of denial of the native landscape.
Cultural Roots
Tensions between the European Australians and the Swan Coastal Plain have their roots in the colonization era; the difficulties of the early settlement ended up influencing the settlers approach to the land also in terms of Beauty perception. Life in the early colonies was not easy and threads like drought, epidemics and floods; the landscape seemed to fight hard the permanent establishment and this created a general feeling of resentment in the new inhabitants. The river the settlement was layed on was considered sick and unhealthy, surrounded by many wetlands that altredy have been object of prejudice. This stigmatisation of the river could have been due also to some intense algae blooms, that are still affecting the river today, and of the consequential odours2. Events like that consolidated once more the resentment for the native landscape. In the urban expansion this tension was given specific form in the conquest of the bushland, carving in the thick canopy the room for new dwellings. In all this confusion, surrounded by endless bushes, vulnerable to their new land and its ancient inhabitants, the settlers found shelter in their english gardens, marrying formally the Old Continent landscape aesthetic. It is also possible to make a relation between the idealisation of the English culture and the imposition of a landscaping tecnique that belonged to a more affirmed and historically reassured country. The cultural inferiority complex of Australia and - in general- many other colonies toward their mother Country, denied almost completely the possibility of a succesfull adaptation to the new landscape, that has been, so to speak, directly replaced with the beautiful english garden. The fracture between the bush and the city is still open, and today the bushland is removed to make room for developable land to much faster pace than 200 years ago. In these new developments, in their parks and gardens, almost any trace of the original vegetation is lost.
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White Australia It’s important to consider the ripercussions that this attitude had on the aboriginal community. These people were bounded to their land in a way that goes beyond the basic livelihood. The Swan river and the surrounding territories were also the linchpin of their cultural identity and their gnoseologic system. The european occupation of these areas caused to Noongar people a cultural upheaval of unimaginable proportions.Aboriginal people have been considered from the beginning an inferior race -following a sadly well known attitude of colonial suprematism- and consequently massacred. In Fact, behind the history of Western Australia, is hidden the history of a White Utopia, and the treatment reserved to aboriginal people has been a clear example. The several abuses that have been committed against Aborigines were spread countrywide, including slavery, racial segregation, genocides and abductions, often with federal regulamentation. From 1890 to 1970, for example, more than 100’000 childrens have been separated from their families and assigned to ecclesiastic institutions or orphanages, with the conviction that aboriginal kids could learn to fit in the white society, if took from their family and reeducated. The vastity of these abuses, perpetrated almost sistematically for a long time, almost caused the entire loss of Aborigines on Australian land that are now the 2,3% of the population3. They became a minority; the incredible richness of their cultures and languages have been almost totally washed away and such a great loss of human knowledge has to be added to the count of the damages that have been caused to the original australian diversity from the English and, after, from the European Australian.
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Ricci, A. (2017). Unsprawling Perth from the Swan River.
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Bolleter, J. (2015). Take me to the river.
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Australian Bureau of Statistics. Census 2006.
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fig. 1 - Herdsman Lake
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fig. 2 - Eucalyptus and Jarrah forest
fig. 3 - Cangaroo hunting scene
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fig. 4 - Kings Park
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fig. x - lorem ipsum blah bla
fig. 5 - Harold Boas Park
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Chapter 2
Wildfire
A regional scale phenomenon
Exponential Growth
The colony had a rather slow demographic growth until the 1850, when the convict era started. When the Swan River Colony became a penal colony the number of inhabitants went quickly from 3’000 to 16’000 inhabitants, the majority of which where male convicted. When the deportation were over, Perth demographic growth slowed again and started to increase constantly due to the discover of gold in the northen territory; in the years after 1890 the growing rate was so fast that the population increased of 400% in a single decade. Perth’s economic fortune had another exploit between the ‘70s and the ‘80s with the so-called Iron Ore Rush, a rush to heavy metals that made Perth population jump to 600’000 inhabitants. Today, the City tripled the population of the ‘80s reaching more than 2 millions inhabitants. It can be seen that continuous urban and demographic growth in this city had been always related with migration flows of big proportion, fueled by an economic history in constant excalation (fig. 1).
Second generation Pioneers
As been said in the previous chapter, the colonial life had a significant crisis with the arrival of convicted in the late 1800 that had a big urbanistic impact: population was then still relatively small, but the speed of the arrivals caused congestion in the english settlement and, consequently, big problems of health and dwellings. The lack of infrastructure that characterize the new developments was jeopardizing the economic growth of the colony; in order to improve the connections to the northen mines of Geraldton and Northampton, in the 1871 the first railway
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track has been built, followed by the construction in 1881 of the Fremantle-Perth-Guildford line. The secondary implication of this technological innovation was the birth of a second generation of pioneers that were able to move from the crowded estuarine settlement and the tent city in the outskirts to make their homes directly carving the bushland. In these new yet-to-be suburbs, the colonists had a lot of disposable land for cheap prices: the flip side of this deal was lack of roads, sanitation and, in general, of any kind of urbanization. Consequently, new dwellings required total independence and lots were big enough to access to groundwater sources and to disperse the waste water into the landscape without contamination (these assumptions were quite aproximate and did not prevent the risk of contamination). The lot size, then, a quarter of acre, aproximatively 1’000 square metres. The big size of the lots allowed the neat distinction between frontyard and backyard that used to have complementary functions. The backyard used to be bigger and was used for animal farming and horticulture, while the front garden played the role of social display, where the inhabitants stated their position in the community; the care of the front garden was, in this perspective, an act of active partecipation to the birth of the social fabric. In the new settlements, suburban roads were often built by the colonists themselves and were the scene of community life and consequently the frontyard played also the role of informal public open space, permeable and with no fences, that became typical of australian suburbs and that was already iconic in the american ones. ‘The front yard was both a zone of display and a social contract, a semi public space of neatness encoding a statement about individual personality in the context of community’ Robert Freestone
Reading the suburban section horizontally, it is recognized a privacy gradient from the road, fully public, to the backyard, private and fenced, through the front garden, semi-public: in this context it is explained the role of the street reserves, commonly called verges, another filter space between the street and the garden. This is a system of linear public spaces formally belonging to the City Council, while its custody and maintance are charged on the owner of the house in front of it.
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Town Planning Development Act
Houndred years of expansion with no regolamentation led to a proper urban planning emergency in the suburbs. In this years, the situation gave birth to different private organizations aimed to give the new suburbs the minimum of primary urbanization they needed to function. Governamental action only took place in 1928, with the introduction of the first Town Planning Development Act. From that year on, the suburbs have been included in the colony design, the connection to water and discharge system have been drawn, allowing a small reduction of the historical quarter of acre lot. In the Town Planning Development Act, also the house seatback was settled to a minimum of 7,6 metres from the road, making the front garden wider and implicitly remarking its importance.
The Metropolitan Regional Scheme
The cultural disruptions that characterized the decade after the Second World War involved Australia too, that was living the war from the sidelines. Answers from urban planning were late as usual, but ten years after the end of the war, in 1954, a new urban planning tool was being designed: the Stephenson Hepbourn Plan, the plan that would have guided pretty little Perth in becoming a global metropolis. It is interesting to notice that the modernization designers of Perth, Gordon Stephenson and Alistair Hepbourn, have been called directly from Liverpool. I think that this highlights that sort of inferiority complex that is quite common in colonial Countries, known as cultural cringe. However, in the plan are defined the limits of Perth metro, already considerable pretty generous, of 110 km on the coast and 50 km to the inland. This area has been recently implemented to include the areas around Mandurah and Harvey. The definition of such a huge developable land, in such a flat landscape, has surely promoted the urban sprawl phenomenon. Another important element that has been introduced by the Metropolitan Regional scheme has been the hierarchy menagment of Public Open Spaces, which definiton was previously charged on the councils with no further regulamentation. The availability of POS has been assured in the Plan by the imposition of transfer to the Crown 10% of all developed lands, to be used as community public space. Regional Public Open spaces are also defined, allowing the safeguard of more or less extended areas of native bushland. Finally, consequently a big infrastructure enhancement, the lot size was once more reduced and its dimensions have been settled to
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13 metres large and 45 metres long, for a total area of 585 square metres. After the introduction of the Metropolitan Regional Scheme in 1964, all the suburbs could count on a generous system of public open spaces and on a very extensive roads web, in order to bring together the fragmented town into a well connected metropolis.
Suburbia, the result
Starting from the 1960, Western Australia had an incredible economical growth, together with an exponential demographic growth. Urban design answered quickly but with a monotone way; the city got bigger with the addition of the northen and the southern suburbs but, if the expansion have been in line with the demographic growth, the variety of solution has not been quite impressive (fig. 2). Nowadays, Perth landscape is summerized in a suburban carpet unrolled on 120 kilometers of coast, conquered piece by piece with a cut and fill1: this approach follows always the same iter. First, the bushland is logged and the orography resoluted2, then one storey houses are built one close to the other either on a grill, reminding of the old scottish Perth, or either on long and winding roads reminding, with not much fantasy, the theoretical garden city of the 19th century (fig.3). As the city spread, the public open spaces followed the trend and green spaces are percieved , even if the mean POS per capita is not so impressive (in Perth, is calculated an average of 33 square meters per capita, against i.e. 440 square meters per capita in Trento, Italyx). This perception is mainly due to the presence of the verges, not counted as public open space, that can sometimes be 16 meters wide and cover, like in the case of Bayswater, nine times the areas of formal POSx. Thanks to this extensive green system, Perth still offers shelter to some of its indigenous species, mainly exotic-looking birds.Many bird species adapted to urban life and became exploiters; some other specialist species, like the Black Cockatoo, are now endangered for loss of habitat and struggle to adapt to their new ecosystems. The impact of Perth settlement on the Swan Coastal Plain Ecosystem has been widely studied as well as the pros and cons of urban sprawling as a develompent paradigmax. Recent studies started to inspect the relation between the ratio of green spaces per capita and the psychological wellness of Perth suburbs population3. It has been proved that the quality of open spaces (meaning the maintenance level as well as the percieved beauty) directly influence the mental condition of the surrounding inhabitants. The reservation of 10% of developed land for public open space doesn’t gua-
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rantee a good liveability of the neighbourhood, but could actually worsen the living condition of the area. That might sound obvious, but this research open the issue about how green a liveable city should be. After all, it’s not hard to imagine that all this green, flat lawns can cause a sense of bewilderment, watering down the already unconfined (if compared to european standards) distance between inhabitants. A rarefied city, big lawns in different watering conditions, with the vastity of Indian Ocean on the front and nothing but bushland and desert behind its back. Perth really does look like the most isolated city in the world, geographically, but also socially.
Desire for density
In the latest decades the cut and fill expansion model started -hesitantlyto be replaced, due to the forecased demographic growth and a generically more responsable environmental attitude. As opposed to the urban sprawling that dominated Perth landscape for the last century, recently two directives Plans have been published, called Network City and Direction 2031: those documents set urban infill targets that encourage the construction on brownfield. Thanks to Western Australian big lot size, urban infill is a pretty common practice based on the fragmentation and selling of the preexistent lot. In general, this should also encourage the construction of higher density dwellings, but one/two storey houses are still the most common by far. Combined urban infill and higher density dwelling should have allocated -starting from 2008- more than 47% of the new dwellings, in order to avoid the dissolution of Perth urban fabric and also to exploit the previously bult infrastructures. These targets haven’t been seen positively by the housing market; today the construction on brownfield is much below its target, scoring only 28% against 78% on greenfieldx. Although urban infill is quite common, people in Perth have shown hesitation in accepting multi-storey houses, probably for affection to the Australian dream of property and the social and economical statement that it implies. In Como, southern suburb, a case of this recalcitant behaviour has been reported, when locals fought, and consequently lost, a legal war to stop a six storey building that was planned to be constructed in a one-storey houses dominant streetx. In fact, only 6% of the inhabitants of Perth have renounced to a semi-detached house to move into an apartmentx; facing this market urban infill has been considered an acceptable compromise, allowing a mild densification of the neighbourhood without losing the suburban landscape(fig.4, fig.5).
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1
Weller, R. (2009). Boomtown 2050.
2
Kullmann, K. (2014). Towards topographically sensitive urbanism: re-envisioning earthwork terracing in suburban development.
Âł
Francis, J., Wood, L., Knuiman, M. and Giles-Corti, B. (2012). Quality or quantity? Exploring the relationship between Public Open Space attributes and mental health in Perth, Western Australia.
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fig. 1 - Demographic history of Western Australia
fig. 2 - Two Rocks
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fig. 3 - cut and fill
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fig. 4 - Bayswater, 2007
fig. 5 - Bayswater, 2017
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Chapter 3
Waterbills
Green ≠Sustainable
Footprints The great ecological footprint of Western Australia (14.5 hectares per capita) is due to an economy fuelled by exploitation of mineral resources, high standards of living and very high per capita consumption. Food production, crop irrigation and the transport system have a major impact on the environment of Western Australia. Only the use of soil associated with food production causes 46% of the ecological footprint. Urban and green sprawl, which caused the dilution of the urban fabric, have made Perth the first Australian capital for car dependency1. Although Australia is one of the drier continents of the world, the consumption of water is very high. The Western Australian suburban lifestyle includes gardens and playgrounds that are considered very important by residents, but also imply the use of plants and herbs unsuitable for drought conditions and consequently a general disergard of water as a scarce resource. The Australian Dream of Property materialize also within the high evaluation of large gardens. A well-tended english garden is, today as it was then, a status symbol and the choice of non-indigenous essences in an essential ontributor to the region’s water footprint. In fact, 41% of all water consumed in the Perth metropolitan region has been assessed for irrigation of private gardens and public open spaces, relying on conditions water availability expectedto worsen dramatically. Considering the overall ecological footprint of the city, it can be said that the management of the public open spaces seems much greener than it is. Analyzing the datas on hydric consuption per suburb provided by the WaterCorporationx , it follows that they are condsiderable water drains due to their landscaping model (fig. 1, fig. 2). The older suburbs, so-called inner suburbs,have a moderate water consumption, while the situation worsens in the neighboring areas of more recent constructions. The title for the most
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expensive suburb goes to Peppermint Grove, a rich and conservative neighborhood, very fond of the English landscape model, with an average of 402 kL per connectionx, well above the regional average. It is interesting to note that Peppermint Grove has remained the last suburb where the lawn on the street reserve is mandatoryx.
Drinking Water
Currently, the drinking water supply of the Perth metropolitan area is guaranteed by Water Corporation through the Integrated Water Supply Scheme, or IWSS. This scheme provides water not only for Perth Metro, but also for the irrigation of the Harvey and Waroona agricultural region and the Goldfields east to the urban fabric. Overall, in 2016 the IWSS distributed 283 gigaliters of water, of which 245.6 only in Perth Metro, 14.8 in Mandurah and in the South West while 23.1 were dedicated to the Goldfields agricultural regionx. These water consumption rate is disproportionate to the surface water availability, which in 2016 scored just 11 gigalitres at the damsx. Despite the dryness of the reservoir, Perth can count on a very large and deep aquifer system, which provide up to the 40% of IWSS supplies. The dams are currently used mainly as storage of water produced by desalination plants or extracted from deep aquifers. The total capacity of the dam system is 630 GL, of which 40% is used on average. Without refills from aquifers and plants, the dams could provide only 6% of the water supplied by the IWWS. The remaining water availability is guaranteed by desalination plants and in follows that is climatically independent. The two desalination plants of the metropolitan area, the Perth Seawater and the Southern Seawater, produce respectively 45 and 100 GL of drinking water per year, with the programmed enlargement of the second one in order to reach the production of 150 GL. To ensure further water supply, there are plans to build two other plants north and south of the city. The desalination process takes place by reverse osmosis of the Indian Ocean water and, while the transformed water is sent to the users, the salts produced by this process are poured into the Ocean. The average salinity of the Indian Ocean water is 33 g/L, and consequently the current production of 122 GL of desalinated water entails the discharge into the Ocean of 4 million tons of salt per year, about 11,000 tons/day. The potential impact of this intensive exploitation on the chemical equilibrium of the ocean regions facing the plants may not be understood until it is too late. These salts, mainly Sodium Chloride with other dissolved minerals such as Boron,
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could be recycled and reused. The same applies to wastewater treatment systems; there are more than 170 wastewater disposal centersx, but in most cases the treated, recycled water is then dispersed in the landscape or discharged into the ocean. Today there are very few recycled water recovery systems, scarcely used also for the recharge of aquifers (fig. 2), mainly because the public opinion is generally against and because the administration position on this topic seems opaque; an awareness campaign in this regard could be an opportunity to turn this cost into a potential profit, also amortizing environmental costs. Currently, solid waste products from sewage treatment are recycled as fertilizers. Flanking the public production and distribution of drinking water, managed by Water Corporation, there is the private water supply system of deep waters, extracted through the so-called garden bores, whose consumption is not monitored but only estimated. The unsupervised supply of this resource has historical roots that date back to the first lots divisions. In 2012, it is estimated that 370 GL of non-potable water were extracted with this system, of which 47% was used for irrigation of public green (60 GL) and private green (114 GL)x. It can be said that, overall, the metropolitan area of ​​Perth consumed about 610 GL of water, excluding those sent to agricultural regions: this implies a water consumption per inhabitant of 370 KL per year; Italians, for instance, consume on average 78.5 KL per year3, less than a third of the average Western Australian.
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1
Weller, R. (2009). Boomtown 2050.
2
Water Corporation (2009). Water forever, towards climate resilience.
Âł
Istat, European Environment Agency (Eea).
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fig. 1 - Water consumption per connection, 2016
fig. 2 - Detached houses on total dwellings, 2016
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fig. 4 - Water consumption 2016/2017
fig. 5 - Waste water discharge
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Charpter 4
Hard times yet to come Is it raining, man?
Demographic projections
Although it is likely that one day the population of Perth will stabilize, since its foundation it has been steadily increasing. The most recent estimates by the Australian Bureau of Statistics forecasts for 2061 a population that varies between 4,4 and 6,6 million inhabitants, compared to the two million currently living in the region1. Although these statistics may seem dramatic, histolically Perth the demographic growth has always confirmed or surpassed the forecasted statistics. In any case, if in the next forty years the population of Perth should actually reach six and a half million inhabitants, it would be necessary to build more than two million homes. By perpetrating the current expansion model the kilometers of urbanized coastline could become 170 and requiring the construction of more than 13’000 km of connction infrastructures2. Furthermore, around 825 GL of water would be needed in addition to the current existing supplies for the population. It should then be investigated how much water could be required to the following industrial and commercial growth and consumed for irrigate more or less 15 additional square kilometers of parksx.
Desertification
If the demographic growth is a reasonable concern, the pressures on the territory caused by the exploitation of resources and climate change have to be investigated too. Land exploitation have already heavily modified the environment and the climate of the region;the trend does not seem to change. From pre-industrial times, the already scarce rainfalls have decreased constantly and reached the lowest on record3 (fig. 1). It is important to underline that the relationship between precipitation and
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surface water availability is not linear, but depends on several factors, including soil composition, evotraspiration, soil moisture, intensity of the solar radiation, etc., etc.. The Avon River reservoir is unfortunately very vulnerable from this point of view due to the porous and sandy nature of the soil and to the intrinsic aridity of the area: a 10% reduction in precipitation would correspond to a reduction in surface water availability of the 35% -40%, together with the salinization of the soil with consequent decrease of fertility of the land4. In fact, these projections are confirmed by the records of water availability to the dams, which is decimated compared to the pre-industrial erax (fig.2). Perth desertification problem could become so important to turn Perth into the first ghost capital city of the twenty-first century5. ‘South-West Western Australia is one of the most water challenged parts of the country, experiencing Australia’s highest rates of climate change and dryland salinity amid rapid population growth and associated development.’
The water rush
Water Corporation has recently published two reports on future water needs and how they plan to secure the water supply of the metropolitan area with a 10 and a 50 year strategy.In fact, in these reports the future water emergency and the increasing unreliability of surface waters are strongly underlined; the company forecasts a 40% reduction in rainfall with a consequent drop in the surface water harvest to 55 GL, so poor that it could no longer be considered a reliable water resource. In the documents, the forecasted water yeld is the result of a combination of strategies: what is noticeable is that even the most optimistic scenario by 2050 would not satisfy the needs of six and a half million inhabitants(tab 1). Currently, the annual water consumption per inhabitant is about 174 KL per capita and it is supposed to reduce down to 125; the strategy also aims to increase the use of recycled water from the current 6% to 30% in 2030. This is an ambitious and hardly achievable goal, that only comes from the close collaboration of Water Corporation and government and local administrations, and also a strong sensibilization and awareness campaign. There is a chance that in future most of the treated water will be recycled, but the question remains as to where and how the wastewater from this process is discharged. Besides the reduction in consumption per capita and the increase in recycled water, this strategy focuses above all on the development of new water resources. The new resources
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envisaged are mainly the construction of two desalination plants north and south of Perth to support this city corridor, and the implement of the existing southern desalination plant to add 50 GL to the production. The desalination technology is an incredible tool for human survival under desertificating conditions; nevertheless it is important to see it as a double edged sword. As it is already been said, although the ocean has an immense supply of water, we are aware that this is not available infinitely: it isn’t a inexhaustible resource, and it has to be consideredth the alteration of the balance of natural cycles that will obviously occur. We are also aware that eventually strong alterations lead to re-assessment feedback systems that often go beyond our forecasting capabilities. Part of the development of new resources planned by Water Corporation consists in the improvement of the technologies that allow deepwater recesses and recharge. Unfortunately, also the phreatic level of the main aquifers is at historical lows and the level curves of the Gnagnara have strongly changed due to extractions (fig.3). The poor monitoring of actual extractions from aquifers and of subsidence phenomenon of the territory, combined with soil feedback systems that could alter the chemical composition of the water, could make depth aquifers a questionable resource for the future.
High tide
Perth is built on the coast of the Indian Ocean and on the shores of the Swan River. The city has remained quite far from the Indian Ocean, thus maintaining its original dune system as protection, while it is squeezed around the river estuary, that consequantly has developed all the features of an urban river. The stability of the banks is therefore vital for the urban functions and unfortunately could be compromised due to the implications of climate change. Taking for example an RCP emissions scenario 8.5 (IPCC assessed record 2014), which is unfortunately in line with current GHG emissions a sea level rise of 78 cm is expected by 2100, reaching 1.58 AHDIn this scenario the projections show the impairment of 126 kilometres of inhabitated river shores and 14 square kilometres of inland area. The submergence of 14 roads, 30 reserves and 19 parks is expected. It would also be interesting to study the role that subsidence could play in this scenario, given the intense exploitation of deep aquifers. Unfortunately, research in Western Australia is quiet on this topic; it is easy to assume that there are also repercussions in this respect. Just look at the case of Romagna, an italian region in the north east, in simi-
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lar conditions of exploitation, where the subsidence phenomenon significantly accelerate coastal erosion due to sea level rise. According to Professor Pattiaratchi, teacher at University of Western Australia, the total damage caused to the city in this scenario could overcome 700 million dollars, of which 104 million located exclusively in the area of ​​the upper estuary, settlement of Perth CBD6. This potentially dangerous scenario requires the attention of design.
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1
Australian Bureau of Statistics (2012). Demographic projections.
2
Weller, R. (2009). Boomtown 2050.
3
Australian Bureau of Metereology, historical records.
4
Swan River Trust (2007), Potential impact of climate change on Swan and
Canning river. 5
Flannery, T. (2005). The future eaters.
6
University of Western Australia (2017), Flood Mitigation Strategies for the Swan River in Response to Sea Level Rise.
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fig. 1 - Rainfall history
fig. 2 - Dams Water level records
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GL/Year
2008
2020
2030
2060
Desalination
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95
95
95
Surface Water
90
85
75
25
Groundwater
145
110
90
30
Total
280
290
260
150
tab. 1 - Projections of water harvesting from existing resources
fig. 4 - Gnangara contours, 1984-2017
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Charpter 5
Welcome to Perth Wandju nidja Boorloo
Introduction City of Perth was one of the first colonial outposts and is currently home to the Central Business District of the Perth metropolitan region. The dominant feature of the landscape are tall buildings, oriented parallel to the river in the East-West direction, which constitute a strong vertical element in an otherwise topographically flat panorama (fig. 1). Kings park would have originally been the predominant vertical element, but now the escarpment has lost its importance due to the comparison with the adjacent high skyscrapers and the reclamation of Mounts Bay for the construction of the motorway junction. Historically, the river bank has been dredged and reclaimed several times, resulting in an essentially flat and linear riverfront. Mainly the coast is bordered by limestone containment walls which acts as a visual barrier and limits access to the water’s edge. In any case, the most restrictive land use of the coast is the junction of Narrows Bridge and Riverside Drive. These streets are extremely busy and serve both the business center and the metropolitan area. The user of the river shore is physically confined to the narrow lawn belt by the geometrically shaped streets. Langley Park is a large extensive lawn that completed this belt along with the Esplanade reserve, now replaced by the marina of Elizabeth Quay, which runs parallel to the river (fig.2, fig. 3). The geometric shape of the green lawn is emphasized by the planting of exotic trees around the park boundaries.
Geology and reclamations
The area is part of the undulating topography of the Sperwood dune system which is slightly slimmer than the surrounding Bassendan dune system1. The site of the city was rather hilly in origin, but most of the hills were leveled during the last century to allow the construction of buildin-
49
gs; most of the coast has been reclaimed and the original wetlands have been filled, along with numerous fresh water springs and lakes (fig. 4). The north shore of Perth Water, even before the reclamation, was relatively straightforward to Point Fraser, a system of tidal shallows that bent into the water in a South-East direction. Perth Water is now a large basin between the Narrows and the island of Heirisson, with no trace of the original curves of Mounts Bay and Point Fraser; it covers approximately 327 hectares (about half of its original extent) and is very shallow, with an average depth of one meter. The water conditions of the basin change seasonally and depend on the volume of water in the river. The winter conditions are of relatively fresh water due to higher rainfall, while the salinity of the river grows during the summer due to poor rainfall conditions and the evaporation that follows high temperatures. The salinity therefore fluctuates from 25 ppt to 30 ppt seasonally (from brackish to salty) and it is influenced by the tides. The periodic flooding of the coast is made impossible, to date, by limestone containment walls, but historically the flat territory underwent frequent flooding. The largest registered were in 1847, 1907 and 1922x , all in the winter months, causing serious infrastructure damage. Today, coastal erosion is prevented by retaining walls, but the river without this protection system would be a dynamic system with high erosion during the winter and settling during the summer.
Original vegetation
The native vegetation of the site is the flora of the Vasse Complexx. This vegetative complex appears in a mixture of dense Melaleuca shrubs, fragments of Eucalyptus forest and other species of Melaleuca. It would also include a forest of Tuart (Eucalyptus Gomphocephala), Jarrah (Eucalyptus Marginata) and Marri (Eucalyptus Calophylla) in the elevated areas. The marshes system would have originally supported Melaleuca of the marshes (Melaleuca Rhaphiophylla), Moonah (Melaleuca Pressiana) and Melaleuca of salty waters (Melaleuca Cuticularis), swamp Sheoak (Casuarina Obesa) and Coojong (Acacia Saligna)3. In the Perth area very little has remained of the original indigenous species. Except for Kings Park, recognized as a reserve in 1895, the rest of native plants are transplanted. In the city, the parks have been planted mostly with exotic trees, following the aesthetic of English landscape in vogue. Along Mounts Bay Road, figs and maples have been planted and grass has been sown Along Riverside Drive are several types of palm trees, including cotton palm and dates. The gardens of the government house and the bark
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square were planted using a formal design and exotic plants, mostly perennial, by color.
Public Open Space
In 2016, Perth counted 24244 inhabitants, covering an area of ​​almost 14 square kilometers. Of these, 39% was dedicated to public green, making City of Perth the suburb with more public green per capita of the entire metropolitan area, with 110 square meters per inhabitant. To distinguish Perth from the surrounding suburbs and their statistics (33 square meters per inhabitant on average) is the presence of the native reserve of Kings Park, which alone covers 69% of the total public green. This heavy contribution must be considered in the interpretation of statistics on public green space. Perth boasts 10.7% tree cover over the total areaX, which is quite impressive. However, it does not reflect the perception of the friutor: the trees are concentrated in the reserves and there is no trace of an urban forest. Furthermore, 64% of these trees are said to be nativeX, but would fall to less than 10% if Kings Park were excluded from the statistics. Although numerically important, in fact kings park is a concentrated nature reserve that greatly unbalances the statistics and does not affect much the perception of widespread public green. Except, therefore, Kings Park and the Point Fraser reserve, affected by a recent native revegetation intervention, the public green is homogeneous, with the classic shaved lawn crowned by more or less tall and more or less exotic perimeter trees ( fig. 5). This landscape occupies only 30% of the total public green area but requires much more intensive and frequent irrigation5 and is held responsable for the majority of Perth water consumption. It is important to note that of all this lawn, 95% is dedicated to passive recreation6 and 5% is ornamental surrounding infrastructures (fig. 6): the few square meters dedicated to active recreation are in private or paid clubs. In 2016, the city of Perth consumed 5’345 KL of drinking water from the scheme, some of which were also used for irrigation of public spaces7.
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1
Wheeler, J. and Wheeler, C. (1984). Swanland.
2
Australian Bureau of Metereology, historical records.
3
Lefroy, E. (1990). Native grasses in South Western Australia.
4
City of Perth (2016). Perth City Snapshot 2016.
5
Webb, M. (2013). Australian native plants.
6 7
Postool.com.au. City of Perth (2016). Perth City Snapshot 2016.
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fig. 1 - Perth Cty
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fig. 2 - Esplanade Reserve
fig. 3 - Elizabeth Quay
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fig. 4 - Reclaiming history
fig. 5 - Supreme Court gardens and Langley Park
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fig. 6 - The Narrows Bridge
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Chapter 6 A strategy
Soft boundaries
Low lying and vulnerable
As has already been said, the orography of the areas surrounding Perth Water is leveled and very flat, thus vulnerable to flooding. In the scenario of sea level rising taken into consideration, several portion of the shores will be interested by tidal flooding: the most compromised areas, as seen from the projections1, are the large park of South Perth, Heirisson island, Langley park and East Perth, and the Narrows junction area, mostly on south bank, near Mill point (fig. 1). The most affected area is definitely Langley park, where the high tide is expected to completely submerge the park to advance to Terrace Road and also compromising the buildings that directly overlook it. It is quite ironic, as predictable, that the areas most affected by the phenomenon of flooding are precisely the areas that have been reclaimed from water some years ago. Current coast containment systems are unsuitable for this type of circumstances and consequently, last year, UWA published a study on flood mitigation strategies by 2100 and the resulting expected economic damage. Economically, the areas most affected are Langley Park and the South Perth shore, where respectively 32 and 70 million dollars of damage are expected2. In general, the whole area surrounding Perth Water is likely to be severely compromised and, apart from the infrastructure damage, the damage in terms of cultural heritage and public space made inaccessible must be considered. The strategy proposed by the UWA team pivots on the installation of an anti-storm barrier at the railway bridge, near Fremantle, with the aim of protecting the city from extreme events whose frequency and intensity are expected to increase starting from 2050. It is estimated that, to prevent road compromise, the barrier will activate as the sea level exceeds one meter, and it is expected to close 47 times by 2050. With regard to the proposed adaptation of the shores of Perth Water, the inter-
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ventions are not structural but mainly involve the installation of vertical barriers or the planned withdrawal of the coast; Vertical glazing barriers are foreseen in the areas with the greatest tourist attraction, while passive barriers are foreseen for the areas less affected by the tides, such as Mounts Bay Road after the Narrows junction. However, this type of vertical barriers are anything but attractive and these delicate circumstances could be a starting point for reflecting on the river-city relationship and its possible evolution.
Strategia di controproposta
Following the projections of damage extrapolated from the research of Professor Pattiratchi, a counter-proposal has been elaborated that foresees the adaptation of the shore to the periodic movements of the estuary. An infrastructural retreat on the north bank is proposed, with the elimination of the trunk of Riverside Drive after the Narrows, and the driveway traffic is torn over the current Adelaide Terrace, in order to creating a buffer zone for the reception of the estuary and the its dynamics. The principle is to defend the nodal infrastructures but without fighting the natural processes. Likewise, even the compromised zones of the cycle paths that cross the area have been redesigned according to their usability in the case of an increase in sea level. The choice of a vertical barrier near Langley Park is necessary to protect the buildings on the river bank, but it is preferred to find an alternative solution to a glass wall; I propose the creation of a usable embankment, to be integrated into the redesign of the traditional waterfront park system. The areas subject to periodic flooding are planted with halophyte vegetation, given the salinity of the estuary; the need for adaptation and water scarcity have the only solution, in my opinion, the choice of native vegetation. Native vegetation has always been the custodian of this land and has adapted to the precarious conditions of a saltwater estuary. Furthermore, the exhibition intent of river dynamics and population education is considered part of the project strategy. Sensitizing the inhabitants to the beauty of the native landscapes will, hopefully, lead to greater environmental awareness. It is hoped above all to introduce an environmentally sustainable alternative to the otherwise homogeneous landscape of the waterfront: one day, perhaps, the fracture between Perth and its landscape will be repaired and this intervention is meant to be a stich. Finally, the strategies applied in the project depend on the use of space. The area of ​​Langley Park and East Perth have the possibility to become functional parks for the service and defense of the urban fabric: consequently they are entirely walkable
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spaces with a strong urban component before the embankment. The area immediately north of the Causeway entrance is being transformed and the construction of a complex of tall buildings with mixed functions is underway; being subject of transformation has not been included in the strategy because it is estimated that the so called “ Waterbanks” project has already provided for the security of the area. Heirisson Island, whose function was that of landmarks and passive recreation, does not require a total practicability, and this allows the development of a marshy system that enriches the Perth Water landscape and provides an educational experience on the beauty and fragility of coastal systems. As for the Narrows junction or, more precisely, the reclaimed area of Mounts Bay it is practically unused due to the heavy intrusion of the motorway; in this case I have suggested exclusively a work of xeric revegetation, in order to drastically lower the water costs of a non-usable area. As for the shore of South Perth, the strategy of backward coast and installation of glass floodwalls was considered appropriate and consequently has not been further investigated.
Garden/garden
The garden/garden experience, a monitoring experiment promoted by the municipality of Santa Monica in 2004, is proposed as a case study. The project involved two adjoining suburban gardens, one maintained in a traditional garden, shaved lawn and exotic vegetation, while the other was transformed into a native garden with endogenous plants (fig. 4, fig. 5). Subsequently, the two gardens were monitored for one year in order to quantify the difference in terms of water footprint, maintainence required and waste produced. The numbers spoke for themselves: the water required by the native garden is only 17% of that required for maintaining a traditional garden, and even the waste and hours of work required are more than halved; the native garden, however, has an initial cost increased by 30% compared to the more common lawn, but it is a price considered amortized in the short period.
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1
Coastalrisk.com.au.
2
University of Western Australia (2017), Flood Mitigation Strategies for the Swan River in Response to Sea Level Rise.
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fig. 1 - High tide in a RCP 8,5 scenario
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fig. 2,3 - Changes in roads and pedestrian paths
fig. 4,5 - garden/garden
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Chapter 7 Leeve park
An urban levee
Analysis Despite the economic and engineering commitment spent for the reclaimings and nourishments, the strong infrastructuralization of the reclaimed land has caused a break between the city and the north bank: urban activity is addressed inland more than to the river bank, and oriented parallel to it, while the reclaimed plain is flanked on both sides by two roads, Riverside Drive, the major traffic artery on the long river, and Terrace Road, parallel and backward of about one hundred meters. After the reclamation, the plans for drawing the Perth Water coast were the most varied, but none of them managed to seduce the community enough to direct a change1. The north bank has always been a dormant bank, little exploited and sits quietly at the foot of the CBD, urban scale version of the suburban frontlawn. The drivable infrastructures along the river are not much more than a reinterpretation of the twentieth-century landscape matrix of scenic driving. As a result, the river bank is not part of the urban culture except as an embellishment to rush hour traffic and Perth Ciy workers and locals generally prefer to go elsewhere to spend their free time. These tampering seem to have broken the relationship between Perth City and Perth Waters, also seeing the design stalemate in which the shore has fallen and the subsequent loss of interest from public life; it can be said that not only the reclamation and maintenance of this landscape have been and still are very expensive in economic and environmental terms, but also that these costs don’t really find a justification for the lack of interest from the community. The construction of the marina of Elizabeth Quay by TLC broke the designing silence and started a dialogue with the waterfront, partially reintroducing the relationship between the city and the river, welcoming it in an artificial bay that replaced the gigantic lawn that was the dominant element of the Esplanade
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Reserve. The design intent is to dialogue with Elizabeth Quay in a work of revitalization of the waterfront, this time aware and respectful of the estuary that hosts it and its needs.
Terrace Road
Terrace road, named Bazar Street at the time of the Swan River Colony, played a vital role in the birth of the original Perth settlement. Terrace road is thus recognized as a historical infrastructure and as such integrated into the design of the park as a paved plate (fig. 1). Traffic is being divested on the current Adelaide Terrace; Terrace Road and the trunks between it and Adelaide Terrace are pedestrianized, thus encouraging also the perpendicular connections to the river and the scenic views. The pedestrian streets perpendicular to Terrace Road visually connect to the park, extending beyond the profile of the main road towards the bank that dialogues with these in the definition of the areas of the river park. If the structure of the park is determined by the vertical curves parallel to the shore, the functions and structure of the park are determined by a horizontal scan of the potentials of the route. The aim is to connect Elizaberth Quay to Point Fraser completing the transition to a more exploited river landscape and at the same time more aware of the environmental dynamics. The Terrace Road plate widens to include the Perth music Hall and the Supreme Court. Perth Music Hall is a concert hall with an important cultural attraction, while the Supreme Court is a beautiful colonial building built in 1903 and is considered a historical heritage to be protected and enhanced. The inclusion of the aforementioned in the Terrace Road plate was intended in order to enhance the cultural points along the river bank and give character to the pedestrian promenade.
Leeve park
The crest of the leeve touches the three meters high ensuring the securing of the area and on the northern front, facing the city, houses a system of large terraces with native vegetation, which soften the geometric shapes of the enbankment and make it a part of the urban park entirely usable. On the south side the bank becomes steeper and at its foot a shoreline has been designed with very gentle topography to allow the development of a system of tidal shoals. The movements of the river are welcomed in a delimited area, whose vegetation will reflect that of the swampy areas of the Vasse complex. In the long term, it is expected that this system will stabilize on a dynamic equilibrium of eroded zones of exposed embank-
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ment and areas of sandy deposits with small bays The clear geometry of the cycle path follows the former Riverside Drive coastal infrastructure but deviates from the road to a ring built at Point Fraser (fig. 2). The marshy system of Point Fraser, obviously, can’t be restored, but in its place it has been imagined a landmark recognizable by both Kings Park and the nearby platforms with views of the Heirisson islands. In maintaining the rigid line which, certainly in a controversial manner, has distorted the Perth Water landscape, there is the will to preserve a historical memory of this manipulation. Its importance in defining Perth’s current landscape would be enough to somehow consider its recovery; moreover it wants to be a memory of an attitude towards the autochthonous landscape that has been attempted, with this project, to overcome. Educational panels on water level changes and amphibious habitats present in the south of Western Australia, together with information on the ecosystem destroyed by urbanization works, are planned inside the river park and on the cycle path.
Heirisson Islands
The geometry of Heirisson Island as we know it today is the result of various manipulations, to then be switched into a public space of mainly passive recreation. Before the foundation of the Swan River Colony, this area was called by the Noongar populations “Matagarup”, literally “deep one leg”, to identify the chain of sandy estuary stretches: since memory, this was the easiest point for crossing Perth Water. The island still preserves this feature of crossing point therefore I considered to maintain and secure the highway connecting East Perth to Victoria Park, known as the Causeway. Given the very flat orography, good part of the surface of Heirisson Island in 2100 is periodically flooded by the high tide and a large portion of the southern part of the island will be permanently submerged. The intrusion of water will most likely divide Heirisson Island into two islands bridging the most depressed areas during high tide, exposing during the low tide a strip of land. It is evident that in these precarious environmental conditions, Heirisson Island is no longer considered a suitable habitat for the colony of gray kangaroos that inhabit the southern area in semi-captivity; consequently,I considered to move the colony of kangaroos into a non-urban reserve. Apart from the colony of kangaroos, the island is uninhabited and presents no infrastructure: the only paved road is the Causeway that cuts the island horizontally. As we said, the structure of the island changes radically in the 8.5 RCCP scenario and this has led to reflections on the possible educational character
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of this landscape complex. In fact, completely preserving the structure of the island as a historical memory would entail other major works of nourishment, while I preferred to design a tidal landscape, modifying the topography to obtain a controlled channeling of the high waters, modeling, so, with a consistent height difference, the interaction between usually dry areas and areas that are likely to be flooded daily. The profile of the new coast is given by subtracting to the original profile the areas subject to continuous flooding and is contained by a cordon of low rocks. The tongue of land emerging during the low tide, connecting the northern and southern part of the island, is seen as a design inspiration for the design of a walking path, submerged under certain conditions of flooding. In fact, it was decided to exploit the transformism offered by the tides to evoke, at least conceptually, the system of original shoals. The passage from one island to another is not guaranteed by engineering works, but is available in non-exceptional conditions.The same type of reasoning is also at the base of the water channeling and the consequent “archipelago� aspect of the project of the northern part of the island (fig. 3). On the whole, the island is not accessible except through the prefigured path system, connected to plates overlooking the marshy wetlands, the Point Fraser ring, the nearby Burswood Peninsula and the Leeve Park. Finally, a eucalyptus forest was planted on the sides of the causeway, which acts as a visual and acoustic buffer around the motorway (fig. 4).
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1
Bolleter, J. (2015). Take me to the river.
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fig. 1 - Leeve park
fig. 2 - Bike path at Point Fraser
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fig. 3 - Heirisson archipelagus
fig. 4 - Eucalyptus and Jarrah buffer forest
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Chapter 8
The Narrows The city entrance
Analisys The Mounts Bay area is burdened by a large motorway infrastructure and is one of the busiest junctions in the metropolitan area. A cycle/pedestrian path runs alongside the river bank and guarantees access to the city of cliclists and pedestrians. Apart from this, the area is rarely used if not for the crossing, even if you often see amateur fishermen under the Narrows Bridge, which was also fishing area for the Noongar communities1. The junction is currently vegetated with native trees and meadow; the trees are quite mature but appear isolated from each other and do not show any stain or undergrowth, except in the areas bathed by lakes, whose vegetation is interesting and can be taken as a reference for the rest of the intervention. Wildlf lowes Although Mounts bay area is not predicted to be affected by significant flooding by the end of the century, it is suggested to withdraw the junction arm closer to the coast, given the likely increase in frequency of extreme events and the importance of the motorway in the region road network. The dismantling of the Riverside Drive Trunk that connects the junction to Elizabeth Quay is made to this effect. This creates the opportunity for a more linear development of the cycle path that connects Mounts Bay Road and Elizabeth Quay, which runs in the project next to the cliff to contain the coast. The coastal retainement is made of big cutted cliffs that replaced the previously used gabions always with a view to protecting this infrastructural node. In addition, the artificial lake in the David Carr Park is expanded by incorporating the ornamental pond from which it was divided by the dismantled highway trunk. This area is
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a typical transformed landscape and the native vegetation is suggested to restore naturalness and soften the clear geometric shapes of the junction. Dialoguing with the native vegetation of Kings Park, the narrows has the opportunity to extend this system by creating a declared Australian green area at the entrance of the city. From this point of view, I proposed a zoning dividing the area into four xeric vegetation systems, ie resistant to long periods of drought and practically independent of rains. The native vegetation of South Western Australia has several species with this characteristic, adapted through the centuries to the climatic conditions of the area. For the higher areas there is a system of native prairies and shrubs, offering a native version of the lawn with trees that now occupies it. Low essences have been chosen not to interfere with lateral visibility of the junction. For the central strip outlined by the rails I don’t suggest a revegetation work but a gravel and mulch repaving. In the southern part of the junction, the areas next to the lakes have been replanted with native halophyte vegetation, implementing or reconnecting - in the case of the David Carr Park - existing vegetation systems. Around these areas I proposed the planting of Australian wildflowers, native plants from the hinterland whose colors attract thousands of tourists every year for the blossoming: the exposure of these wildflowers could enhance the beauty of the arid surrounding landscape in the eyes of passersby, drivers and tourists. The essences are grouped by color to create a scenic effect that can strike the eyes of both visitors and users of the junction (fig. 1, fig. 2, fig. 3, fig. 4).
Net savings
The water saving expected from the conversion has been calculated. In the tables below, the liters per week required by the two different types of crops were listed, the currently dominant shaved meadow2 (table 1) and the native vegetation3 (table 2). The data on native vegetation refer to the irrigation of the adjacent Kings park. As can be seen at a glance, the native vegetation requires occasional irrigation and only in the warmer months,compared to of shaved lawn that is irrigated weekly except in the months of the ‘sprinkler ban’x. As can be seen from the above calculations, conversion to native vegetation is likely to lead to a total water saving of 66%.
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tab. 2- Native vegetation
tab. 1- Lawn
L/week/m2
L/week/m2
January
30
January
20
February
30
February
20
March
20
March
/
April
14
April
/
May
14
May
/
June July August
June
Sprinkler ban
Sprinkler ban
July August
September
14
September
/
October
14
October
/
November
20
November
/
Dicember
20
Dicember
20
tot
176
tot
60
Water use before transformation: 176 L/week/m2 ∙ 4o weeks ∙ 209061 m2=
1471 ML
Water use after transformation: 60 L/week/m2 ∙ 12 weeks ∙ 195006 m2=
1
Swan River Trust (2010), Indigenous story of the river.
2
Perthturfsupplies.com.au.
3
Webb, M. (2013). Australian native plants.
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140 ML
fig. 1 -Native plants, Yellow tones
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fig. 2 - Native plants, red tones
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fig. 3 - Native plants, White tones
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fig. 4 - Native plants, Purple tones
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Chapter 9
Happy ending? The importance of drawing in contest
In this project, tidal marshes and native vegetation dominate the Perth Water landscape and enrich the city with a functional and educational waterfront. What I aimed to achieve, and I hope I did, is just a line in the design of a capital city that does not deny the landscape that hosts it. However slowly, Perth is already taking this direction, with policies to raise awareness about native vegetation logging and the enhancement of cultural and environmental heritage. I hope that mine is just one of many project ideas that insert Perth in its landscape context without forcing the fragile ecosystem. I also hope that the city councils and public administration of the metropolitan area will make a joint effort to educate the inhabitants so that water is considered a precious resource, especially facing the future water scarcity that will affect the area. Adapting to impervious climatic conditions requires the unanimous commitment of the community and the administration must have a transparent approach to the problem, which is now lacking. There are virtuous programs, unfortunately with a limited audience, such as the CRC guidelines for Perth Water Sensitive City. On the other hand, programs such as Water Corporation’s fifty-year water supply plan, with the slogan “Water forever, whatever the weather�, perpetrate objectives that are difficult to achieve and generally influence the community in maintaining environmentally irresponsible attitudes that we now know too well. Developed countries such as Western Australia have the means to oppose drastically to desertification and it is in their total interest to act in this direction. The results of the conversion are summarized in the tables below (table 1, table 2).
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tab. 1 - Land use percentage - Before transformation
Lawn
Undergrowth
Native
Waterbody
Roads
Tidal habitat
Narrows
63%
5%
0%
9%
23%
0%
Langley and East Perth
56%
0%
11%
3%
30%
0%
Heirisson
79%
0%
0%
10%
5%
6%
TOT
65%
2%
5%
84
7%
21%
0%
tab. 2 - Land use percentage - After transformation
Lawn
Undergrowth
Native
Waterbody
Roads
Pedestrian
Tidal habitat
Lost
Narrows
0%
8%
59%
14%
19%
0%
0%
0%
Langley e Perth est
0%
0%
45%
3%
0%
21,5%
30%
0,5%
Heirisson
0%
0%
42%
2%
4%
3%
26%
23%
TOT
0%
2%
48%
6%
85
6%
10%
21%
7%
Bibliography Monographies Bolleter, J. (2015). Take me to the river. Ferry, L. (2009). The new ecological order. Chicago, Ill: The Univ. of Chicago Press. Ricci, A. (2017). Unsprawling Perth from the Swan River. Laurea magistrale. UniversitĂ degli studi di Ferrara. Seddon, G. (1988). Sense of place. [Perth, W.A]: [Murdoch University]. Webb, M. (2013). Australian native plants. Collingwood, Vic.: CSIRO Publishing. Weller, R. (2009). Boomtown 2050. Crawley, W.A: UWAP/UWA Pub. Wheeler, J. and Wheeler, C. (1984). Swanland. Yu, K. and Padua, M. (2006). The art of survival. Victoria: The images publishing group. Articles Bolleter, J. (2016). Background noise: a review of the effects of background infill on urban liveability in Perth. Australian Planner, 53(4), pp.265-278. Bolleter, J. (2016). On the verge: re-thinking street reserves in relation to suburban densification. Journal of Urban Design, 21(2), pp.195-212. Gobster, P., Nassauer, J., Daniel, T. and Fry, G. (2007). The shared landscape: what does aesthetics have to do with ecology?. Landscape Ecology, 22(7), pp.959-972.
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Lefroy, E. (1990). Native grasses in South Western Australia. Kullmann, K. (2014). Towards topographically sensitive urbanism: re-envisioning earthwork terracing in suburban development. Journal of Urbanism: International Research on Placemaking and Urban Sustainability, 8(4), pp.331-351. Francis, J., Wood, L., Knuiman, M. and Giles-Corti, B. (2012). Quality or quantity? Exploring the relationship between Public Open Space attributes and mental health in Perth, Western Australia. Social Science & Medicine, 74(10), pp.1570-1577. Rogers, B.C., Hammer, K., Werbeloff, L., Chesterfield, C. (2015). Shaping Perth as a Water Sensitive City: Outcomes of a participatory process to develop a vision and strategic transition framework. Melbourne. Reports Australian Water Resources Assessment (2012), South West Coast. City of Perth (2016). Perth City Snapshot 2016. Department of Water (2012), Annual report. Swan River Trust (2009), Annual report. Swan River Trust (2010), Indigenous story of the river. Swan River Trust (2007), Potential impact of climate change on the swan and Canning river. Swan River Trust, Swan and Canning river protection strategy.
University of Western Australia (2017), Flood Mitigation Strategies for the Swan River in Response to Sea Level Rise. Water Corporation (2009), Water forever, towards climate resilience. Water Corporation (2011), Water forever, whatever the weather. Websites Coastalrisk.com.au. (2018). Coastal Risk Australia. [online] Available at: http://coastalrisk.com.au/. Dpaw.wa.gov.au. (2018). Home - Parks and Wildlife Service. [online] Available at: https://www.dpaw.wa.gov.au. Nationalmap.gov.au. (2018). NationalMap. [online] Available at: http://www.nationalmap.gov.au/. Postool.com.au. (2018). CBEH POS. [online] Availatble at: http://www. postool.com.au/cbeh/pos/welcome/. Perthturfsupplies.com.au. (2018). Water Information | Perth | Perth Turf Supplies. [online] Available at: http://www.perthturfsupplies.com. au/watering-information.
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Greetings
Thanks, in order of appearence Mamma PapĂ Nonna Carla e Nonna Fede Chicco Duofi Santerenzo Ferrara Doni Vero Fabry Juan Lisboa Totta Chiara Perth Stephen Tim Anto Paris Emanueli Vittoria Alice
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Graphics
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