sustainability

Article Soil and Water as Resources: How Landscape Architecture Reclaims Hydric Contaminated Soil for Public Uses in Urban Settlements

Isotta Cortesi 1, Laura Valeria Ferretti 2,* and Federica Morgia 2

1 DiARC, Università degli Studi di Napoli Federico II, 80130 Napoli, Italy; [email protected] 2 DiAP, Sapienza Università di Roma, 00185 Roma, Italy; [email protected] * Correspondence: [email protected]



Received: 3 September 2020; Accepted: 5 October 2020; Published: 24 October 2020


Abstract: Soil is one of the fundamental components for life on Earth, but today, as a consequence of humans’ unsustainable actions, soil is polluted, distressed and spoiled. In contemporary practice design, we recognize the importance of the soil quality to structure new discourses in landscape practice. The central role in this process is undoubtedly played by the value a healthy soil has for the community and for the environment. The strategic design of wet and hydric landscapes is certainly an essential aspect for the regular and exceptional management of the effects produced by pollution and climate change. The research develops the soil as a key subject in the landscape design, specifically in hydric environments where water represents an important factor. The essay is divided into three parts: resources and opportunities of disturbed wet soil, successfully built public space where soil remediation transformed heavy polluted industrial urban sites in fertile public ecosystems within the dense urban structures, and soil design as a domain of urban resilience. The landscape project as an integrated project has spread the seeds of a new approach to the consideration of the contemporary city in an ecological manner.

Keywords: soil; water; contamination; public places; waste; landscape architecture; water sensitive cities; overflow and flood; remediation; unstable urban landscapes

1. Introduction In contemporary practice, we recognize the importance of the soil quality to structure new discourses on the city. In fact, after several decades where soil has been systematically exploited and polluted as if it were an interminable resource, now we face an important change in paradigm on which we build our discussion [1]. Particularly, in this essay, we focus on how landscape architecture responds in relation to the soil quality to design open spaces. Soil is one of the fundamental components for life on Earth, but today, as a consequence of humans’ unsustainable actions, soil is polluted, distressed and spoiled. Moreover, soil has the capacity to improve the climate or poison the atmosphere. For this reason, it should be at the center of future environmental and urban policies. The central role in this process is undoubtedly played by the value a healthy soil has for the community and for the environment. Climate change, exceptional floods, atmospheric precipitation and sea level rise have profound effects on soil quality: erosion, pollution—due to the impact of overflow water management systems—soil contamination—due to flooding—and soil damage—due to soil sealing [2]. An important FAO research [3] affirms that soil plays a key role in water supply and is resilient in floods and in droughts. It captures and stores water, making it available for crops, minimizes surface evaporation while maximizing water use efficiency in agriculture [4], and it interacts with the climate,

Sustainability 2020, 12, 8840; doi:10.3390/su12218840 www.mdpi.com/journal/sustainability Sustainability 2020, 12, 8840 2 of 25 mitigating the effects of heating in cities. Its ability to retain water is important both in periods of drought and in the increasingly frequent periods of heavy rains [5], because it slows down the outflow. The strategic design of wet and hydric landscapes is certainly an essential aspect for the regular and exceptional management of the effects produced by climate change. Since the late 1960s, there has been a growing interest in environmental issues: the habitability of the planet and the sustainability of resources in relation to the population. Every year, since 22 April 1970, we celebrate Earth Day, renewing the principles expressed by Barry Commoner [6], who was the main proponent of the four laws of Ecology:

1. Everything is connected to everything else. There is a single ecosphere in which all living organisms survive and the effects on one of them have consequences for all the others; 2. Everything must go somewhere. There is no waste in nature because everything is part of a chain that connects matter and energy; 3. Nature knows best. Every change caused by man can produce damage to the natural system; 4. There is no such thing as a free lunch. In ecology, there is no profit that can be achieved without a corresponding cost.

In this global scenario, architecture and landscape projects are necessary means for the Care of the physical world; while defending it, they understand and revise the causes of the transformation’s phenomena. Architecture re-affirms a new ethical value and becomes responsible for a new relationship of stewardship between humans’ actions and nature [7]. The architect is, according to Ian McHarg, an ecological planner since he leads the discipline “into a board multidisciplinary tool of resource management and land use planning” [8].

2. Materials and Methods The research develops the soil as a key subject in landscape design, specifically in hydric environments where water represents an important factor. The essay is divided into three parts:

1. First part: The Beauty and the Beast. Resources and opportunities of disturbed wet soil. This part Identifies interventions in which, starting from former landfills, in environments characterized by the presence of water, design intervention has managed to overturn the landfills’ conversion into a new hydric ecosystem. The essay proposes a reclamation of disturbed lands and a landfill remediation taxonomy, which implements design strategies focusing on two main topics: the Performance of Nature and the Recovering Landscape, both improving a new Aesthetic of Ecology [9]. Through design and the ecological landscape’s restoration, contaminated soils assume new forms and values becoming new landmarks and new contemporary parks, recovering lost cultural and natural values. 2. In the second part we observe, in the built environment, paradigms where the Aesthetic Experience in relation to the Environmental Ethics transforms polluted industrial urban sites into fertile public ecosystems. We discuss European models: successfully built public space where soil remediation has transformed heavily polluted industrial urban sites into fertile public ecosystems within the dense urban built environment. These places are now accessible to people, becoming an active part in the cultural life of cities. This part of the essay develops a possible framework for the conversion of brownfields into new ecosystems where water plays a fundamental role in the remediation processes, structuring different design categories for contemporary public spaces in densely populated cities: Hypernature as Esthetic Experience, Public Nature as City Culture, Operative Nature as Environmental Ethics. 3. The third part explores soil design as a domain of urban resilience. The landscape project as an integrated project has spread the seeds of a new approach to the vision of the contemporary city in an ecological manner. It is a change of direction for which it is not just a matter of greening the cities, strengthening ecological networks or designing gardens, but it is also a matter of more and Sustainability 2020, 12, 8840 3 of 25

more being done to insert real fragments of nature—efficient ecosystems—into the urban fabric by reconnecting the city with the its original natural context. Water and the related soil project are an essential component of context-based projects because they use existing resources that would otherwise be dispersed and, by introducing a time variable, allow the planning of an incremental evolution of places, this being the concept behind a new generation of landscape urbanism.

In this part we will therefore see how some interventions, namely the soil projects, manage to transform floods or overflow phenomena from risk factors to resources by creating new unstable urban landscapes.

3. First Part: The Beauty and the Beast. Resources and Opportunities of Disturbed Wet Soil In the culture of contemporary design, open spaces for public use acquire the same importance as built space. In the 19th century, Frederick Law Olmsted realized new urban public parks as spaces of urban social, cultural and environmental reform. For a founding father of American landscape architecture, these kinds of new public spaces “performed in two ways: first, they were environmental cleaning machines, open spaces of healthy sun light, well-drained soils, and shady groves of trees reducing temperatures, absorbing carbon dioxide, and releasing oxygen. Landscape architectural works such as urban parks, promenades and boulevards, public gardens, parkways, and suburban residential enclaves were cultural products that responded to, and then altered, the processes of modernization and urbanization” [10] (p. 92). Due to environmental disasters and a climate change largely caused by human action, the importance of green spaces has increased further. Paradoxically, waste and pollution, especially in the case of wet soil, can be a potential resource for the well-being of the environment in which we live. Nowadays in the context of a “permanent emergency” strategy, to cite Rem Koolhaas, the issue is not the creation of an ideal environment but the opportunistic exploitation of the unexpected, the accidental and the imperfect [11]. Gradually and inevitably, we are learning from our mistakes and attempting to improve upon them with better choices for a more sustainable and resilient design. Nature itself is teaching us how. We must learn from how natural processes self-regulate and apply these conditions to the way in which we design and transform our spaces. Accumulation of waste is a progressive process which involves a level of soil saturation which the end of the process extends beyond. Soils contaminated by the accumulation of debris from anthropogenic actions, where the waste has stratified, can be transformed into new landscapes. Waste disposal sites have been converted into renovated natural areas with new purposes since the second half of the 20th century [12] (pp. 96–98). It has since then become more popular to work with so-called waste parks or disturbed sites. For these sites to be considered safe, processes of remediation are necessary before the grounds can be used. Frequently, these sites are turned into parks by using water as a fundamental element to trigger this transformation. The remediation project is entrusted to the ecological and sustainable component able to trigger a virtuous mechanism that allows the environment to find a new ecological balance over time. This essay identifies some illustrative examples of new landscapes created from the transformation of contaminated places strongly characterized by the presence of water. It proposes a taxonomy of landfills and wastewater remediation, through the conversion of disturbed sites into a new wet habitat, which implement different design strategies on two main topics: Performance of nature and Recovering Landscape.

3.1. Performance of Nature. Design Engages Nature’s Intelligence to Reduce Harmful Human Impact Landscape ecology studies and aims to understand and improve relationships, such as composition, structure and function, in the ecological process and the landscape system. Ecological restoration is the process of assisting the recovery of damaged, degraded or destroyed ecosystems. Both are focused on reversing the biodiversity extinction crisis. They are expansive breadth of ecological theory, in which Sustainability 2020, 12, 8840 4 of 25 nature’s in-built performance solves the problem of environmental pollution, influencing landscape architectureSustainability 20 [1320,]. 12, x FOR PEER REVIEW 4 of 25 Over 80% of wastewater is discharged into the environment without adequate treatment around Over 80% of wastewater is discharged into the environment without adequate treatment around the world. The paradigm of wastewater management has to shift from treatment disposal to reuse, the world. The paradigm of wastewater management has to shift from treatment disposal to reuse, recycling, and resource recovery. Meanwhile, an ecologically friendly and cost-effective solution is recycling, and resource recovery. Meanwhile, an ecologically friendly and cost-effective solution is needed. Many wastewater treatment processes have been designed to improve water quality. From the needed. Many wastewater treatment processes have been designed to improve water quality. From biological characteristics of the aquatic environment, endemic vegetation, such as water hyacinth, the biological characteristics of the aquatic environment, endemic vegetation, such as water hyacinth, giant reed, microalgae and duckweed, have shown capability in pollutant removal. Duckweed, a kind giant reed, microalgae and duckweed, have shown capability in pollutant removal. Duckweed, a of floating aquatic plant, is widely distributed around the world and comprised of many species and kind of floating aquatic plant, is widely distributed around the world and comprised of many species different genera (Figure1). and different genera (Figure 1).

FigureFigure 1. 1.Floating Floating duckweed. duckweed. Duckweed Duckweed belongs belongs to the to botanicalthe botanical family family of Lemnaceae, of Lemnaceae, they are they divided are intodivided four generainto four Lemna, genera Spirodela, Lemna, Spirodela, Wolffia, and Wolffia, Wolffi ellaand ofWolffiella which, to of date, which, more to thandate, 40more species than have 40 beenspecies identified. have been identified.

DueDue to to this this ability,ability, this this plantplant hashas alreadyalready been used for the treatment treatment of of domesti domestic,c, industrial industrial and and swineswine wastewaters. wastewaters. The The most most eff effectiveective result result is obtainedis obtained through through the the use use of di offf erentdifferent aquatic aquatic plants plants at the sameat the time same because time the because advantages the advantages of various duckweedof various species duckweed are integrated. species are Recent integrated. contemporary Recent theorycontemporary and practice theory of sustainable and practice landscape of sustainabl designe have landscape a higher design regard have for the a higher performance regard of for nature the inperformance the remediation of nature design in the process remediation [14]. design process [14]. OneOne of of the the leading leading exponents exponents of this line of research is is Viet Viet Ngo, Ngo, a a Vietnamese Vietnamese student student of of engineeringengineering and and artart inin thethe USA,USA, who,who, fromfrom his early wo works,rks, showed from from the the outset outset an an interest interest in in the the environmentenvironment and and the the land.land. ThisThis interest developed into research research that that lies lies between between environmental environmental and and publicpublic art, art, and and he he founded founded a researcha research institute, institute, Lemna Lemna Company, Company, that that promotes promotes the treatmentthe treatment of water of pollutedwater polluted by toxic by waste toxic by waste means by ofmeans a natural of a natural and environmentally-friendly and environmentally-friendly system, system, using nousing electric no powerelectric or power chemical or chemical agents. Ngoagents. became Ngo became increasingly increasingly interested interested in creating in creating work that work would that addresswould environmentaladdress environmental issues and issues merge and his merge artistic his sensibilities artistic sensibilities with problem with pro solving.blem solving. In creating In creating Lemna, heLemna, aimed he to transform aimed to wastewater transform wastewater treatment facilities, treatment which facilities, are necessary which are pieces necessary of infrastructure pieces of usuallyinfrastructure hidden usually awayor hidden disguised, away intoor disguised, parts of theinto landscape. parts of the Inlandscape. 1990 Ngo In applied 1990 Ngo his applied method his of watermethod treatment of water and treatment purification and purifi to thecation Molgora to the River, Molgora an affl River,uent of an the affluent Adda, of in the Adda, north-west in the of Italynorth [15-west]. This of experienceItaly [15]. This was experience realized after was some realized other after previous some projectsother previous such as projects the system such to as purify the thesystem water to of purify Devils the Lake, water North of Devils Dakota, Lake, which North covers Dakota, an areawhich of covers 36 ha andan area filters of over36 ha 13,000 and filters m3 of waterover 13 a day.,000 cubic The schememeters of for water the purification a day. The ofscheme the water for the supply purification was undertaken of the water to supply improve was the undertaken to improve the quality of the landscape and reduce the level of water pollution by fertilizers used in agriculture [16]. Ngo considers himself a multi-faceted artist who receives personal fulfillment through projects that are environmentally responsible and contribute to society. The

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structures designed by him are systems of water purification but look like art installations and landmarks that are capable of producing new public spaces and parks [17] (Figure 2). SustainabilityThe reclamation2020, 12, 8840 process of disturbed lands could represent an opportunity to be both a social5 of 25 change as well as an environment ecological compensation. Vintondale, Pennsylvania, a long- neglected 16-hectare site, had hosted both a coal mining operation and an urban landfill. Toxic orange qualitystreams of and the the landscape absence andof life reduce within the their level banks of water attest pollution to the widespread by fertilizers environmental used in agriculture problem [16 of]. Ngo considers himself a multi-faceted artist who receives personal fulfillment through projects that are devastationSustainability 20 wrought20, 12, x FOR by PEER acid REVIEW mine drainage (AMD). Acid mine drainage is a mixture of highly5 of 25 environmentallypolluting heavy metals, responsible which and regularly contribute seeps to out society. from the The abandoned structures mines. designed Naturally, by him arepassive systems and ofactivestructure water solutions purifications designed for acid butby himmine look are likedrainage systems art installations are of built water out and purificationof landmarks sight, enclosed but that look areby capablea like chain art- oflink installations producing fence (Figure new and public3)landmarks. spaces that and are parks capable [17 ]of (Figure producing2). new public spaces and parks [17] (Figure 2). The reclamation process of disturbed lands could represent an opportunity to be both a social change as well as an environment ecological compensation. Vintondale, Pennsylvania, a long- neglected 16-hectare site, had hosted both a coal mining operation and an urban landfill. Toxic orange streams and the absence of life within their banks attest to the widespread environmental problem of devastation wrought by acid mine drainage (AMD). Acid mine drainage is a mixture of highly polluting heavy metals, which regularly seeps out from the abandoned mines. Naturally, passive and active solutions for acid mine drainage are built out of sight, enclosed by a chain-link fence (Figure 3).

Figure 2.2. Viet NgoNgo appliedapplied hishis method,method, LemnaLemna System,System, ofof water’swater’s treatment and purificationpurification in the Molgora River that looks like a land-artland-art installation,installation, AddaAdda aaffluent,ffluent, inin north-westnorth-west Italy,Italy, 1990.1990.

The reclamation process of disturbed lands could represent an opportunity to be both a social change as well as an environment ecological compensation. Vintondale, Pennsylvania, a long-neglected 16-hectare site, had hosted both a coal mining operation and an urban landfill. Toxic orange streams and the absence of life within their banks attest to the widespread environmental problem of devastation wrought by acid mine drainage (AMD). Acid mine drainage is a mixture of highly polluting heavy metals,Figure which 2. Viet regularly Ngo applied seeps outhis method, from the Lemna abandoned System, mines. of water’s Naturally, treatment passive and purification and active in solutions the for acidMolgora mine River drainage that looks are built like a out land of-art sight, installation, enclosed Adda by a affluent, chain-link in north fence-west (Figure Italy,3 ).1990.

Figure 3. AMD&ART. In Appalachia’s territory, unregulated mining prior to 1977 created a huge environmental problem called Acid Mine Drainage. Inside abandoned mines, ground water reacts with pyrite and oxygen, creating sulfuric acid, which dissolves metals in the surrounding earth, mostly iron and aluminum. Vintondale, Pennsylvania, 1995–2004.

The promoter of the initiative, historian Allan Comp, imagined that the process of reclaiming this territory could be a collective experience that could involve citizens and form a civic, coexistent solution through the employment of art and the engagement an entire community. In 1995, he created a team in collaboration with landscape architect Julie Bargmann D.I.R.T. Studio, the environmental Figure 3.3. AMD&ART. In Appalachia’s territory, unregulated mining prior to 1977 created a huge artist Stacy Levi, and hydrogeologist Robert Deason to envision a treatment system that would environmental problemproblem called called Acid Acid Mine Mine Drainage. Drainage. Inside Inside abandoned abandoned mines, mines, ground ground water water reacts reacts with engage the landscape by creating a park that celebrated the treatment of water, rather than render pyritewith pyrite and oxygen, and oxygen, creating creating sulfuric sulfuricacid, which acid, dissolves which dissolvesmetals in the metals surrounding in the surrounding earth, mostly earth, iron that process invisible [18]. The treatment, named Testing the Waters, is a new method of designing a andmostly aluminum. iron and Vintondale,aluminum. Pennsylvania,Vintondale, Pennsylvania, 1995–2004. 1995–2004.

The promoter of thethe initiative,initiative, historianhistorian Allan Comp, imagined that the process of reclaimingreclaiming thisthis territoryterritory couldcould bebe aa collectivecollective experienceexperience thatthat couldcould involveinvolve citizenscitizens and form aa civic,civic, coexistentcoexistent solution through the employment of art and the engagement an entire community. In 1995, he created a team in collaboration with landscape architect Julie Bargmann D.I.R.T. Studio, the environmental artist Stacy Levi, and hydrogeologist Robert Deason to envision a treatment system that would engage the landscape by creating a park that celebrated the treatment of water, rather than render that process invisible [18]. The treatment, named Testing the Waters, is a new method of designing a

Sustainability 2020, 12, 8840 6 of 25 solution through the employment of art and the engagement an entire community. In 1995, he created a team in collaboration with landscape architect Julie Bargmann D.I.R.T. Studio, the environmental artist Stacy Levi, and hydrogeologist Robert Deason to envision a treatment system that would engage Sustainability 2020, 12, x FOR PEER REVIEW 6 of 25 the landscape by creating a park that celebrated the treatment of water, rather than render that process invisiblepassive water [18]. Thetreatment treatment, solution named for Testing acid mine the Waters, drainage is a1 new9. Rather method than of designing an engineering a passive solution, water treatmentthis project solution both treats for acid the minewater drainage and shows [19 ].the Rather process. than The an Litmus engineering Gardens, solution, hedgerows this project of native both treatstrees and the water shrubs and vivify shows the the process process. of theThe water Litmus treatment, Gardens, reflecting hedgerows the of colornative of trees the and water shrubs as it vivifyprogresses the process throughout of the waterthe treatment’s treatment, reflectingcommunicating the color basins of the from water orange, as it progresses to yellow throughout and then the to treatment’sgreen. The communicatingproject has achieved basins a fromdual orange,objective to to yellow give the and town then of to green.Vintondale The projecta chance has to achieved reclaim aits dual own objective territory to and give to thepreserve town ofthe Vintondale paradox inherent a chance into the reclaim cohabitation its own of territory natural andbeauty to preservewith the theindustrial paradox past inherent and to increate the cohabitationa living solution of natural that framed beauty the with incongruities the industrial of nature past and and to industrial create a livingtoxins: solution to treat that the framed water theand incongruities to show the of process. nature and Local industrial communities, toxins: h toorticulture treat the water groups and and to showcommunity the process. service Local groups communities, were some horticulture of the members groups of andthe community serviceto collaborate groups on were a model some ofredevelopment the members initiative of the community for post-coal to collaborate mining regions on a modeland to redevelopmentinvolve themselves initiative through for a post-coal series of miningneighborhood regions me andetings to involve and field themselves days, tree through planting, a series and working of neighborhood activities meetingsto build site and furnishings field days, treeand planting,create wildlife and working habitats activities(Figure 4) to. The build Vintondale site furnishings pilot project and createtests the wildlife waters, habitats building (Figure a visible4). Thesign Vintondale for communities pilot project to participate tests the waters, in the buildingdynamic a proc visibleess sign of applying for communities progressive to participate science and in thetechnology, dynamic process visionary of applying planning progressive and policy, science and celebrate and technology, heritage visionary with a planning renewed and landscape policy, andexperience celebrate [20 heritage]. With a with focus arenewed on making landscape remediation experience processes [20]. visible With a in focus a new on public making park, remediation the ten- processesyear process visible which in aended new public in 2004, park, the thedidactic ten-year forms process of passive which treatment ended in 2004,for acid the mine didactic drainage forms, ofdemonstrate passive treatments the potential for acid regeneration mine drainage, of neglected demonstrates landscapes: the potential resilientregeneration nature growing of neglected around a landscapes:mixed palette resilient of residual nature pollutants. growing around a mixed palette of residual pollutants.

FigureFigure 4.4. AMD&ART.AMD&ART. AcidAcid MineMine DrainageDrainage throughthrough aa passivepassive treatmenttreatment system,system, relyingrelying onon naturalnatural processesprocesses toto raise raise the the pH pH and and remove remove the the metals. metals. This This type type of systemof system has has several several benefits, benefits, including including low overheadlow overhead and maintenance and maintenance costs. Passive costs. treatment Passive treatmentsystems also systems provide also more provide design opportunities, more design andopportu cannities, create and new can opportunities create new foropportunities historical, for natural historical, and scientific natural and understanding. scientific understanding. Vintondale, Pennsylvania,Vintondale, Pennsylvania, 1995–2004. 1995–2004.

3.2.3.2. Recovering Landscape.Landscape. New Aesthetics of Ecology TheThe topic topic of of landscape landscape restoration restoration means means a form a form of legacy of legacy that needs that to needs be recovered to be recovered and designed and fordesigned new purposes. for new A purposes. deep awareness A deep of awareness the auxiliary of disciplines the auxiliary and disciplines techniques and is introduced techniques into is theintroduced design dimension into the design to give substancedimension to to the give formal substance dimension. to the The formal prolific dimension. landscape ecology The prolific and ecologicallandscape restoration ecology and disciplines ecological significantly restoration influence disciplin landscapees significantly architecture. influence Forward-thinking landscape ecologicalarchitecture. and Forward environmental-thinking planning ecological and and landscape environmental architectural planning practices, and landscape however, canarchitectural diversify theirpractices, scope, however, environmental can diversify effectiveness their scope, and enduring environmental resilience. effectiveness and enduring resilience. InIn thethe FreshFresh KillsKills Park,Park, StatenStaten Island,Island, thethe landscapelandscape project producedproduced a multi-purposemulti-purpose process, implementingimplementing a wetlands system system in in order order to to recover recover the the landfill landfill site. site. In In2001, 2001, to take to take advantage advantage of the of potential for the adaptive end use of the Fresh Kills Landfill, the City of New York, in association with others institutions, conducted an International Design Competition to foster the development of a master plan for transforming the landfill in the Park. The goal was to attract the best talent worldwide, to generate ideas and innovative park designs that would meet the needs of the city’s communities and respond to the natural and constructed history of the site. The Fresh Kills was a landfill covering 890 ha in Staten Island. The landfill opened in 1948 as a temporary landfill, but by

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1955, it became the largest landfill in the world, and it remained so until its closure in 2001. At the peak of its operation, in 1986, Fresh Kills received 29,000 tons of residential waste per day (Figure 5). SustainabilityField 2020Operations,, 12, 8840 founded in 1999 by James Corner and Stan Allen, won the competition.7 ofThe 25 office aims to propose solutions for new public spaces based on the collaboration between new ecologies of creativity and the specific disciplines of architecture, landscape architecture, city the potential for the adaptive end use of the Fresh Kills Landfill, the City of New York, in association planning, ecology and infrastructural and transport system planning [21]. The practice of ecology is with others institutions, conducted an International Design Competition to foster the development of a understood in its broadest sense through sustainable and flexible projects that are amenable to change master plan for transforming the landfill in the Park. The goal was to attract the best talent worldwide, and to increase the amount of public space through formulation of an open matrix on which to to generate ideas and innovative park designs that would meet the needs of the city’s communities construct alternative scenarios for the occupation and identity of the place, actively incorporating and respond to the natural and constructed history of the site. The Fresh Kills was a landfill covering sustainable energy infrastructure. The project envisaged the transformation of the area, over 75% of 890 ha in Staten Island. The landfill opened in 1948 as a temporary landfill, but by 1955, it became the which was occupied by disused industrial structures, into a large natural reserve within the urban largest landfill in the world, and it remained so until its closure in 2001. At the peak of its operation, fabric of New York, enriched by the inclusion of a variety of ecosystems. in 1986, Fresh Kills received 29,000 tons of residential waste per day (Figure5).

Figure 5.5. FreshFresh KillsKills opened opened in in 1948 1948 as as a temporarya temporary landfill landfill and and it remained it remained so until so un itstil closure its closure in 2001. in At2001. the At peak the ofpeak itsoperation, of its operation, in 1986, in it 1986, received it received 29,000 tons29,000 of tons residential of residential waste per waste day. per In theday. picture In the ispicture the landfill is the inlandfill 1974. in 1974.

Field Operations, founded in 1999 by James Corner and Stan Allen, won the competition. The office aims to propose solutions for new public spaces based on the collaboration between new ecologies of creativity and the specific disciplines of architecture, landscape architecture, city planning, ecology and infrastructural and transport system planning [21]. The practice of ecology is understood in its broadest sense through sustainable and flexible projects that are amenable to change and to increase the amount of public space through formulation of an open matrix on which to construct alternative scenarios for the occupation and identity of the place, actively incorporating sustainable energy infrastructure. The project envisaged the transformation of the area, over 75% of which was occupied by disused industrial structures, into a large natural reserve within the urban fabric of New York, enriched by the inclusion of a variety of ecosystems. The constitution of a nature reserve was split into four phases named seeding, infrastructure, programming and adaptation, to be implemented over a span of thirty years. In each of the four phases, Figure 6. J. Corner Field Operations, Freshkills Park, Renowned Landscape Architecture firm. James the processCorner tookField placeOperations in four won di fftheerent 2001 ways: competition circulation, to design surfaces, the park ecology, and its andvast areas program. over the The next aims of the firstthirty phase years, was actively to recover incorporating the landscape, sustainable the original energy infrastructure. natural environment Realization: on which 2010–2040 infrastructures Staten and facilities,Island, New required York. for the different functions, which have been designed to carry out in a dynamic way, the successive second and third phases. The fourth phase conceived an extension of the third phaseThe and constitution consisted ofof thea nature space’s reserve adaptation was split of variations into four inphases the programs named seeding, and the infrastructure, utilization of parkprogramming development. and adaptation, The project to envisaged be implemented a recovering over landscapea span of thirty process, years. capable In each of introducing of the four threephases, di fftheerent process varieties took place of ecosystems in four different [22]. The ways: first circulation, ecosystem, surfaces, named ecology, threads, and was program. based on The a networkaims of the of water first phasedistribution was to and recover nutrient the substances landscape, for the plant original development; natural environment the second ecosystem, on which namedinfrastructures islands, and was facilities, realized required by areas for in whichthe different to create functions, protected which habitats have for been special designed cultivations; to carry theout thirdin a one, dynamic named way, mats, the was successive a system se ofcond permeable and third surfaces, phases. that The regulated fourth phase the erosion conceived and the an transformation of the wet disturbed soil (Figure6).

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1955, it became the largest landfill in the world, and it remained so until its closure in 2001. At the peak of its operation, in 1986, Fresh Kills received 29,000 tons of residential waste per day (Figure 5). Field Operations, founded in 1999 by James Corner and Stan Allen, won the competition. The office aims to propose solutions for new public spaces based on the collaboration between new ecologies of creativity and the specific disciplines of architecture, landscape architecture, city planning, ecology and infrastructural and transport system planning [21]. The practice of ecology is understood in its broadest sense through sustainable and flexible projects that are amenable to change and to increase the amount of public space through formulation of an open matrix on which to construct alternative scenarios for the occupation and identity of the place, actively incorporating sustainable energy infrastructure. The project envisaged the transformation of the area, over 75% of which was occupied by disused industrial structures, into a large natural reserve within the urban fabric of New York, enriched by the inclusion of a variety of ecosystems.

Figure 5. Fresh Kills opened in 1948 as a temporary landfill and it remained so until its closure in Sustainability2001. At2020 the, 12 peak, 8840 of its operation, in 1986, it received 29,000 tons of residential waste per day. In the8 of 25 picture is the landfill in 1974.

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extension of the third phase and consisted of the space’s adaptation of variations in the programs and the utilization of park development. The project envisaged a recovering landscape process, capable of introducingFigureFigure 6. J. J.Cornerthree Corner different Field Field Operations, Operations,varieties Freshkills of Freshkillsecosystems Park, Park, Renowned [22 Renowned]. The Landscape first Landscapeecosystem Architecture Architecture, named firm threads,. James firm. was basedJamesCorner on a Corner networkField Operations Field of Operationswater won distribution the won 2001 the competition 2001and nutrient competition to design substances to the design park for the and plant park its vast anddevelopment; areas its vast over areas the the overnext second ecosystemthethirty next ,years, named thirty actively years, islands, activelyincorporating was incorporating realized sustainable by sustainable areas energy in whic energyinfrastructure.h to infrastructure. create Realization: protected Realization: 2010 habitats–2040 2010–2040 forStaten special cultivations;StatenIsland, Island, New the York. New third York. one, named mats, was a system of permeable surfaces, that regulated the erosion and the transformation of the wet disturbed soil (Figure 6). AThe pioneer constitution of “Water of Urbanism”,a nature reserve Kongjian was Yu,split Turenscape into four Teamphases Leader, named is notseeding, only oneinfrastructure, of the most A pioneer of “Water Urbanism”, Kongjian Yu, Turenscape Team Leader, is not only one of the importantprogramming living and landscape adaptation, architects, to be implemented but also a keen over observer a span of of the thirty present. years. His In design each of proposals the four most important living landscape architects, but also a keen observer of the present. His design andphases, reflections the process on urban took planningplace in four in China different are aways: practical–conceptual circulation, surfaces, reference ecology, with and which program. to attempt The proposals and reflections on urban planning in China are a practical–conceptual reference with which toaims unravel of the emerging first phase questions was to of recover a planet the threatened landscape, by environmental the original natural catastrophes, environment hydrogeological on which to attempt to unravel emerging questions of a planet threatened by environmental catastrophes, risksinfrastructures and water and crises. facilities, In 2005, required in response for the different to calls fromfunctions, residents which to ha improveve been adesigned 22-ha area to carry in a hydrogeological risks and water crises. In 2005, in response to calls from residents to improve a 22- desertedout in a shooting dynamic range way, used the successive as an illegal se andcond extremely and third polluted phases. dumping The fourth ground, phase the conceived government an ha area in a deserted shooting range used as an illegal and extremely polluted dumping ground, the contracted landscape architecture firm Turenscape to create Qiaoyuan Wetland Park. The site was government contracted landscape architecture firm Turenscape to create Qiaoyuan Wetland Park. located in downtown Tianjin where the surrounding community reaches a population of nearly 300,000 The site was located in downtown Tianjin where the surrounding community reaches a population inhabitants. Two original conditions of the site, the shooting area and the earth dyke on the north side, of nearly 300,000 inhabitants. Two original conditions of the site, the shooting area and the earth dyke came to be an opportunity for the landscape architect (Figure7). on the north side, came to be an opportunity for the landscape architect (Figure 7).

FigureFigure 7.7. Kongjian Yu-Yu- Turenscape,Turenscape, QiaoyuanQiaoyuan WetlandWetland Park.Park. ((aa)) ExistingExisting generalgeneral masterplan,masterplan, ((bb)) thethe existingexisting conditioncondition of of the the site: site: a a former former shooting shooting range, range, shown shown as as a garbagea garbage dump dump and and drainage drainage sink sink for urbanfor urban storm storm water, water, heavy heavy polluted polluted with with saline-alkali saline-alkali soil, littered, soil, littered, deserted deserted and surrounded and surrounded with slums with andslums rickety and rickety temporary temporary structures, structure Tianjin,s, Tianjin, 2005. 2005.

InIn anan innovativeinnovative way,way, thethe parkpark isis characterizedcharacterized byby aa micromicro topographytopography throughthrough aa naturalizednaturalized landscapelandscape ofof ponds, ponds, which which all all vary vary in in size size and and depth, depth, where where nature nature does does all the all workthe work by collecting by collecting acid acid rainwater, neutralizing the alkaline soil, repairing the barren urban areas and finally reintroducing the structure of the native wetland that is predominant in the area. The main concepts of the QiaoYuan Park design are starting a natural process restoring the ecosystem and enabling the park to provide diversified ecosystem services to the city, realizing an ecological park with high performance and low maintenance costs [23]. Kongjian Yu uses basic elements derived from Tianjin’s regional natural and cultural landscape features (Figure 8). These components range from plant materials to industrial constituents, and realize different landscapes in different seasons, making the park a complete and rich landscape experience in different moments of the year. Seasonal changes in plant species occur and integrate, successfully balancing the constraints of the urban landscape and thousands of visitors to the park each year, while preserving the integrity of the delicate native vegetation and wetland habitat by using elevated platforms extended over the habitat. This is a

Sustainability 2020, 12, 8840 9 of 25 rainwater, neutralizing the alkaline soil, repairing the barren urban areas and finally reintroducing the structure of the native wetland that is predominant in the area. The main concepts of the QiaoYuan Park design are starting a natural process restoring the ecosystem and enabling the park to provide diversified ecosystem services to the city, realizing an ecological park with high performance and low maintenance costs [23]. Kongjian Yu uses basic elements derived from Tianjin’s regional natural and Sustainability 2020, 12, x FOR PEER REVIEW 9 of 25 cultural landscape features (Figure8). These components range from plant materials to industrial constituents, and realize different landscapes in different seasons, making the park a complete and successful example of a design approach to reestablish natural functions and let the dynamic rich landscape experience in different moments of the year. Seasonal changes in plant species occur processes of adaptation and succession occur. Key steps in the design process included: careful and integrate, successfully balancing the constraints of the urban landscape and thousands of visitors planning and plant selection, experimentation with species, monitoring of progress during the to the park each year, while preserving the integrity of the delicate native vegetation and wetland construction phase as plants became established, and adjusting the design accordingly to achieve the habitat by using elevated platforms extended over the habitat. This is a successful example of a design best performance. approach to reestablish natural functions and let the dynamic processes of adaptation and succession Taking as a model the founding geometries of rural landscapes, Kongjian Yu proposes works of occur. Key steps in the design process included: careful planning and plant selection, experimentation water infrastructure with very low technology that, through adaptive behavior, recompose with species, monitoring of progress during the construction phase as plants became established, intermediate landscapes between cities and nature, concrete representations of the association and adjusting the design accordingly to achieve the best performance. between man and the element that more than any other generates and preserves life, water [24].

Figure 8.8. Shallow and seasonal water pondsponds occupiedoccupied byby diversediverse nativenative communities.communities. The design concept let nature work is is inspired inspired by by regional regional Chinese Chinese landscapes landscapes withwith patchypatchy habitatshabitats sensitivesensitive to subtle changes ofof water andand PHPH values,values, Tianjin,Tianjin, 2005. 2005.

4. SecondTaking Part as a: modelAesthetic the founding Experience geometries and Environmental of rural landscapes, Ethics Transform Kongjian Yu Polluted proposes Industrial works of waterUrban infrastructure Sites into Fertile with veryPublic low Ecosystems technology that, through adaptive behavior, recompose intermediate landscapes between cities and nature, concrete representations of the association between man and the Soil Quality is the persistent capacity of soil to function as a living ecosystem that sustains plants, element that more than any other generates and preserves life, water [24]. animals, and humans. This reveals the importance of managing soils in order to maintain their quality 4.for Second future Part:generations. Aesthetic In Experiencethe design practice and Environmental the consideration Ethics of Transform it as a living Polluted ecosystem Industrial reflects a Urbanfundamental Sites into shift Fertile in the Publicway we Ecosystems conceive the design of public urban space; soil is an ecosystem that provides nutrients for plant growth, absorbs and holds rainwater, filters pollutants, serves for Soil Quality is the persistent capacity of soil to function as a living ecosystem that sustains plants, agricultural production of better food, and provides habitat for microbes to nourish the diversify that animals, and humans. This reveals the importance of managing soils in order to maintain their quality is a necessity for ecosystem cycles. for future generations. In the design practice the consideration of it as a living ecosystem reflects In order to return places to their communities, soil remediation becomes pivotal in these a fundamental shift in the way we conceive the design of public urban space; soil is an ecosystem “disturbed sites” [10], (pp. 59–86), polluted and contaminated landscapes previously used for that provides nutrients for plant growth, absorbs and holds rainwater, filters pollutants, serves for industrial activities. Two paradigms stand, in the recent landscape and city history, as references for agricultural production of better food, and provides habitat for microbes to nourish the diversify that the sustainable, ecological and site-specific decisions in the biological remediation strategies of the is a necessity for ecosystem cycles. site. In order to return places to their communities, soil remediation becomes pivotal in these “disturbed Richard Haag with the Gas Works Park in 1970 built an extraordinary contemporary paradigm sites” [10], (pp. 59–86), polluted and contaminated landscapes previously used for industrial activities. where heavily polluted dirt remained in situ and through active biological processes and the passing of time became cleansed. “Haag embraced a method of soil remediation which involved the excavation of the contaminated topsoil (approximately 20,000–30,000 cubic yards) and subsequent “burial” in the mound (along with the concrete foundations, slabs, pits, supports, and miscellaneous structures) (Figure 9). Soil from the grading of the site and parking lot were spread over the site, and subsequently mixed with bio-degradable elements such as sawdust and leaves to allow air to circulate in the soil. On top of this material, treated sewage sludge, complete with oil-degrading enzymes, was placed and plowed into the soil. The increased air circulation and the sewage sludge enhanced the bacterial action within the soil, bacteria which would break down the harmful

Sustainability 2020, 12, 8840 10 of 25

Two paradigms stand, in the recent landscape and city history, as references for the sustainable, ecological and site-specific decisions in the biological remediation strategies of the site. Richard Haag with the Gas Works Park in 1970 built an extraordinary contemporary paradigm where heavily polluted dirt remained in situ and through active biological processes and the passing of time became cleansed. “Haag embraced a method of soil remediation which involved the excavation of the contaminated topsoil (approximately 20,000–30,000 cubic yards) and subsequent “burial” in the mound (along with the concrete foundations, slabs, pits, supports, and miscellaneous structures) (Figure9). Soil from the grading of the site and parking lot were spread over the site, and subsequently mixed with bio-degradable elements such as sawdust and leaves to allow air to circulate in the soil. On top of this material, treated sewage sludge, complete with oil-degrading enzymes, was placed and plowed into the soil. The increased air circulation and the sewage sludge enhanced the bacterial action Sustainability 2020, 12, x FOR PEER REVIEW 10 of 25 within the soil, bacteria which would break down the harmful chemicals in the soil. This alternative was weighed against that of removing entirely the contaminated soil but this was cost-prohibitive. chemicals in the soil. This alternative was weighed against that of removing entirely the contaminated In 1997, funding became available to address the remaining contamination issues at Gas Works Park. soil but this was cost-prohibitive. In 1997, funding became available to address the remaining Field studies determined that carcinogenic polynuclear aromatic hydrocarbons (PAHs), arsenic benzene contamination issues at Gas Works Park. Field studies determined that carcinogenic polynuclear and toluene as well as non-carcinogenic PAHs in the groundwater exceeded the acceptable levels. aromatic hydrocarbons (PAHs), arsenic benzene and toluene as well as non-carcinogenic PAHs in In addition, the field studies identified two areas within the park which had tar residue near the surface, the groundwater exceeded the acceptable levels. In addition, the field studies identified two areas and this tar and adjacent contaminated soil was removed and remediated using high temperature within the park which had tar residue near the surface, and this tar and adjacent contaminated soil heating system. was removed and remediated using high temperature heating system.

FigureFigure 9.9. RichardRichard Haag,Haag, GasGas WorkWork Park.Park. SoilSoil treatmenttreatment onon thethe formerformer GasGas Plant.Plant. Work onon sitesite waswas experimental,experimental, forfor thethe firstfirst timetime involvinginvolving bioremediationbioremediation andand biodegradationbiodegradation ofof dissolveddissolved organismsorganisms presentpresent inin thethe soil.soil. Seattle,Seattle, 1970–1975.1970–1975.

The cleanup plan consisted of: a protective vegetated soil cover over unpaved open areas and an air sparging and soil vapor extraction system was installed. This system consists of pumping compressed air into the saturated soil as the air moves to the surface it both oxygenates the groundwater and strips volatile organic compounds (VOC), such as benzene, from the soil. This oxygenation of the groundwater stimulates the biodegradation of dissolved hydrocarbons by native organisms present in the soil” [25]. At present, the park is completely integrated in the urban structure and is the place for open air healthy activities, sports and entertainment for citizens (Figure 10).

Figure 10. Richard Haag, Gas Work Park. The successful engagement of people with the former industrial site happens currently. Seattle, 1970–1975.

The cleanup plan consisted of: a protective vegetated soil cover over unpaved open areas and an air sparging and soil vapor extraction system was installed. This system consists of pumping compressed air into the saturated soil as the air moves to the surface it both oxygenates the groundwater and strips volatile organic compounds (VOC), such as benzene, from the soil. This oxygenation of the groundwater stimulates the biodegradation of dissolved hydrocarbons by native

Sustainability 2020, 12, x FOR PEER REVIEW 10 of 25

chemicals in the soil. This alternative was weighed against that of removing entirely the contaminated soil but this was cost-prohibitive. In 1997, funding became available to address the remaining contamination issues at Gas Works Park. Field studies determined that carcinogenic polynuclear aromatic hydrocarbons (PAHs), arsenic benzene and toluene as well as non-carcinogenic PAHs in the groundwater exceeded the acceptable levels. In addition, the field studies identified two areas within the park which had tar residue near the surface, and this tar and adjacent contaminated soil was removed and remediated using high temperature heating system.

Figure 9. Richard Haag, Gas Work Park. Soil treatment on the former Gas Plant. Work on site was Sustainabilityexperiment2020, 12al,, 8840for the first time involving bioremediation and biodegradation of dissolved organisms11 of 25 present in the soil. Seattle, 1970–1975.

Sustainability 2020, 12, x FOR PEER REVIEW 11 of 25

organismsFigure 10.present 10. Richard in theHaag, soil” Gas [ Work25]. At Park. Park. present The successful, the park engagement is completely of people integrated with the in former the urban structureindustrialindustrial and is sitesite the happenshappens place for currently.currently open .air Seattle,Seattle, healthy 1970–1975.1970 activities,–1975. sports and entertainment for citizens (Figure 10). PeterThe cleanup Latz’s Latz’s strategy plan strategy consisted in in Duisburg Duisburg of: a Nord protective Nord since since 1991vegetated focused1991 focusedsoil on cover remediation on over remediation unpaved through open through either areas isolating either and theisolatingan air contaminated sparging the contaminated and dirt soil in bunkers vapor dirt in extraction onbunkers site or on leaving system site or it wasleaving in place; installed. it in allowing place; This allowing it system to improve consistsit to improve quality of pumping through quality phytoremediation,throughcompressed phytoremediation, air into where the Plants saturated where are Plants used soil are asto contain,used the air to contain, degrademoves tode and grade the eliminate surface and eliminate contaminants it both contaminants oxygenates in the soil the in throughthegroundwater soil through their roots, and their strips leaves roots, volatile and leaves life organic cyclesand life (Figure compounds cycles 11 (Figure). In (VOC), addition, 11). In such addition, the Emscher as benzene, the waterEmscher from stream thewater improved soil. stream This throughimprovedoxygenation a seriesthrough of the of marshes,agroundwater series of ponds marshes, stimulates and ponds water the and aeration. biodegradation water aeration. of dissolved hydrocarbons by native

Figure 11. Latz und Partner, LandschaftLandschaft Park.Park. Peter Latz’s strategy focused on remediation through either isolating the contaminated dirt in bunkers on site or leaving it in place,place, allowing it to improve in quality through phytoremediation, where plants are used to contain, degrade and eliminateeliminate contaminants in the soil through theirtheir roots.roots. Duisburg Nord 1991–1998.1991–1998.

Through case studies in Europe focused on soil remediation,remediation, this part of the essay invites discussion about possible future scenarios, relevant theories and project responses in landscapelandscape environmental design. design. The The essay essay develops develops a possible a possible framework, framework, starting starting from from successful successful reality, reality, for forthe the conversion conversion of brownfieldsof brownfields into into new new ecosystems ecosystems where where water water plays plays a a fundamental fundamental role role in in the ground remediation processes, structuring didifferentfferent designdesign strategies for contemporary public spaces in densely populated cities:cities:

4.1. Hypernature as Aesthetic Experience In contemporary design practice, it is fundamental to build convincing aesthetic strategies to make designed forms evident, direct and capable of standing out from the ordinary. Nevertheless, definite form recognition allows the remediation process to be better perceived, considered and valued by the users. This is a fundamental passage for the design success: to go beyond form and become the base of knowledge as a cultural experience. In the London Queen Elisabeth Olympic Park, Hargreaves Associates with a larger group of specialists found multiple solutions to remediate and restore brownfield land with on-site treatment including crushing, soil washing, bioremediation, chemical and geotechnical stabilization, restoring three kilometers of waterways as ecosystems, gaining a biodiverse habitat within the park land (Figure 12). The 247-acre park served as the central feature for the London 2012 Olympic Games, which were recognized as the “Greenest Games” in history, with the park declared the “winner of the Games” by the Mayor of London. The design synthesizes centuries of British park tradition, the reality of post-industrial brownfields, advances in sustainability and resilience thinking to create a new type of park for the 21st Century. The landscape design and the remediation action were focused around the restoration of the water and riparian habitat and ecosystems of the River Lea.

Sustainability 2020, 12, 8840 12 of 25

4.1. Hypernature as Aesthetic Experience In contemporary design practice, it is fundamental to build convincing aesthetic strategies to make designed forms evident, direct and capable of standing out from the ordinary. Nevertheless, definite form recognition allows the remediation process to be better perceived, considered and valued by the users. This is a fundamental passage for the design success: to go beyond form and become the base of knowledge as a cultural experience. In the London Queen Elisabeth Olympic Park, Hargreaves Associates with a larger group of specialists found multiple solutions to remediate and restore brownfield land with on-site treatment including crushing, soil washing, bioremediation, chemical and geotechnical stabilization, restoring three kilometers of waterways as ecosystems, gaining a biodiverse habitat within the park land (Figure 12). The 247-acre park served as the central feature for the London 2012 Olympic Games, which were recognized as the “Greenest Games” in history, with the park declared the “winner of the Games” by the Mayor of London. The design synthesizes centuries of British park tradition, the reality of post-industrial brownfields, advances in sustainability and resilience thinking to create a new type of park for the 21st Century. The landscape design and the remediation action were focused around the restoration of the water and riparian habitat and ecosystems of the River Lea. Sustainability 2020, 12, x FOR PEER REVIEW 12 of 25

Figure 12. 12. Hargreaves Associates, Queen Elisabeth OlympicOlympic Park. The heavily polluted soil from industrial andand chemicalchemical plants plants also also provided provided the the bioremediation bioremediation of threeof three kilometers kilometers of waterways of waterways with biodiversewith biodiverse habitats habitats within within the park the land.park land. London London 2007–2012. 2007–2012.

Nevertheless,Nevertheless, thethe solutions solutions were were conceived conceived in stronglyin strongly recognizable recognizable forms forms for users, for users, as well as being well capablebeing capable of reducing of reduc anding managing and manag flooding risk, flood preparing risk, preparing for a changing for a climatechanging to climate the benefit to the of wild benefit life andof wild people life and in the people public in realm. the public Hypernature realm. Hypernature as a design as concept a design enhances concept the enhances importance the impor of reiterate,tance condensingof reiterate, andcondens exaggeratinging and exaggerat the connectioning the between connection forms between and sustainable forms and processes sustainable (Figure processes 13). (Figure“Design 13). should be form-full, evident and palpable, so that it draws the attention of an urban audience,“Design the should users, distractedbe form-full, by dailyevident concerns and palpable, of work so and that family, it draws or the the over attention stimulation of an urban of the digitalaudience, world the [users,... ]. Thedistr experienceacted by daily of beauty, concerns a process of work between and family, the senses or the and over reason, stimulation an unfolding of the ofdigital awareness, world […]. is restorative. The experience By extension, of beauty, the a process aesthetic between experience the senses of constructed and reason, hyper-nature an unfolding is transformativeof awareness, is [ ... restorative.] aesthetic By experience extension, can the result aesthetic in the appreciation experience of of constructe new formsd of hyper beauty-nature that are is discovered,transformative because […] aesthetic they reveal experience previously can unrealized result in the relationships appreciation between of new humanforms of and beauty non-human that are lifediscovered, processes” because [9], (p. they 17). reveal previously unrealized relationships between human and non-human life processes” [9], (p. 17).

Figure 13. Hargreaves Associates, Queen Elisabeth Olympic Park. The design found multiple solutions to remediate and restore brownfield land with soil on-site treatment including crushing, soil washing, bioremediation, chemical and geotechnical stabilization. London 2007–2012.

Sustainability 2020, 12, x FOR PEER REVIEW 12 of 25

Figure 12. Hargreaves Associates, Queen Elisabeth Olympic Park. The heavily polluted soil from industrial and chemical plants also provided the bioremediation of three kilometers of waterways with biodiverse habitats within the park land. London 2007–2012.

Nevertheless, the solutions were conceived in strongly recognizable forms for users, as well being capable of reducing and managing flood risk, preparing for a changing climate to the benefit of wild life and people in the public realm. Hypernature as a design concept enhances the importance of reiterate, condensing and exaggerating the connection between forms and sustainable processes (Figure 13). “Design should be form-full, evident and palpable, so that it draws the attention of an urban audience, the users, distracted by daily concerns of work and family, or the over stimulation of the digital world […]. The experience of beauty, a process between the senses and reason, an unfolding of awareness, is restorative. By extension, the aesthetic experience of constructed hyper-nature is transformative […] aesthetic experience can result in the appreciation of new forms of beauty that are discovered, because they reveal previously unrealized relationships between human and non-human Sustainabilitylife processes”2020, [129,], 8840 (p. 17). 13 of 25

Figure 13.13.Hargreaves Hargreaves Associates, Associates, Queen Queen Elisabeth Elisabeth Olympic Olympic Park. The Park. design The found design multiple found solutions multiple tosolutions remediate to remediate and restore and brownfield restore brownfield land with land soil on-sitewith soil treatment on-site treatment including including crushing, crushing, soil washing, soil bioremediation,washing, bioremediation, chemical andchemical geotechnical and geotechnical stabilization. stabilization. London 2007–2012. London 2007–2012.

4.2. Public Nature as City Culture Public Nature embeds in the community life the importance of “Nature as a cultural resource for the City dwellers” whether it is soil, water, vegetation or fauna. Public Nature constitutes the vital core in contemporary landscape design and even more clearly in future agenda. Open space is potentially the place of democracy, which possesses the status of a living and fleeting thing. It is therefore an open source process based on change. It is the place of integration, in its condition between the public and private sphere. At the same time, it is the dimension in which Nature, in the Open City, flows and belongs to urban construction, as in ancient times. To put at the heart of any transformation the open, collective and natural space is giving it a primary role in the act of transformation. It has important consequences in the outcomes of contemporary life in cities and urban communities. Peter Latz in the Dora Park in Turin reaffirms the aesthetic of the industrial ruins when transforming brownfields into a fluid open space system along and across the Dora River (Figure 14). “Our new conceptions [ ... ] is a metamorphosis of landscape without destroying existing features, an archetypal dialogue between the tame and the wild. Specific architecture for specific uses does not need to be built. The imagination lets the existing ones be re-interpreted and used in new ways. Artefacts can develop natural processes in derelict surroundings according to ecological rules started and maintained by technological processes. It is the idea of making time visible”, [26]. The river is given back to the citizens, despite the current and unsolved discussion about contaminated water with a heavy quantity of hexavalent chromium flowing through the park. Natural bioremediation processes of contaminated soil are integrated by Latz’s design within urban life, becoming cultural knowledge for people. Most recently Latz und Partner have been working on polluted soil remediation from arsenic contamination of the Spree Park in Berlin, a former D.D.R. amusement park, along the river Spree in the Plänterwald (timber forest) close to the city center (Figure 15). Latz is a world pioneer in soil remediation, focusing on simple and effective natural techniques which generate circular effects on the care of places as well as in the long run on the improvement of human habits with the aim to unite through design, art, culture and nature. Sustainability 2020, 12, x FOR PEER REVIEW 13 of 25

4.2. Public Nature as City Culture

Public Nature embeds in the community life the importance of “Nature as a cultural resource for the City dwellers” whether it is soil, water, vegetation or fauna. Public Nature constitutes the vital core in contemporary landscape design and even more clearly in future agenda. Open space is potentially the place of democracy, which possesses the status of a living and fleeting thing. It is therefore an open source process based on change. It is the place of integration, in its condition between the public and private sphere. At the same time, it is the dimension in which Nature, in the Open City, flows and belongs to urban construction, as in ancient times. To put at the heart of any transformation the open,Sustainability collective2020, 12 and, 8840 natural space is giving it a primary role in the act of transformation. It14 ofhas 25 important consequences in the outcomes of contemporary life in cities and urban communities.

FigureFigure 14 14.. LaLatztz und und Partner, Partner, Dora Dora River River Park. Park. Natural Natural bioremediation bioremediation processes processes of of contaminated contaminated soil soil Sustainabilityareare integrated integrated 2020, 12 ,within withinx FOR PEERurban urban REVIEW life. Turin Turin 2004 2004–2012.–2012. 14 of 25

Peter Latz in the Dora Park in Turin reaffirms the aesthetic of the industrial ruins when transforming brownfields into a fluid open space system along and across the Dora River (Figure 14). “Our new conceptions […] is a metamorphosis of landscape without destroying existing features, an archetypal dialogue between the tame and the wild. Specific architecture for specific uses does not need to be built. The imagination lets the existing ones be re-interpreted and used in new ways. Artefacts can develop natural processes in derelict surroundings according to ecological rules started and maintained by technological processes. It is the idea of making time visible”, [26]. The river is given back to the citizens, despite the current and unsolved discussion about contaminated water with a heavy quantity of hexavalent chromium flowing through the park. Natural bioremediation processes of contaminated soil are integrated by Latz’s design within urban life, becoming cultural knowledge for people. Most recently Latz und Partner have been working on polluted soil remediation from arsenic contamination of the Spree Park in Berlin, a former D.D.R. amusement park, along the river Spree in the Plänterwald (timber forest) close to the city center (Figure 15). Latz is a world pioneer in soil remediation, focusing on simple and effective natural techniques which generate circular effects on the careFigure of places 15.15. LatLatzz as und und well Partner, Partner, as in Plänterwald the long run in the on Spree the improvementPark. The polluted polluted of humansoil remediation remediation habits withfrom arsenic the aim to unite contaminationthrough design along along, art, the the culture river river is focusedisand focuse nature. ond simpleon simple and eandffective effective natural natural techniques. techniques. On-going On- ingoing Berlin. in Berlin. 4.3. Operative Nature Sustains Environmental Ethics 4.3. OperativeNature operates Nature Sustains as the remedy Environmental in soil polluted Ethics sites. Operative Nature stands as an active process, responsibleNature for operates positive as changes the remedy in the in environmental soil polluted sites. quality Operative of the public Nature space. stands Design as an sustains active theprocess, Ethical responsible approach fromfor positive an environmental changes in andthe environmental a cultural point quality of view. of Users, the public through space. the project,Design becomesustains morethe Ethical and more approach aware from of the an environmental environmental values and a cultur beyondal form.point of Operative view. Users, Nature through in urban the spacesproject, values become the more natural and cyclesmore aware in contemporary of the environmental forms improving values beyond the ecosystems’ form. Operative quality andNature the builtin urban space. spaces values the natural cycles in contemporary forms improving the ecosystems’ quality and theThe built selected space. design paradigms of existing fertile public soil ecosystems embed the necessary conjunctionThe selected between design the aesthetic paradigms experience of existing (which fertile goes public beyond soil the appearanceecosystems ofembed forms), the the necessary scientific researchconjunction (ecological) between and the ethical aesthetic responsibility. experience (which goes beyond the appearance of forms), the scientificThe Cuulturparkresearch (ecological) Westgasfabrieck, and ethical in responsibility. Amsterdam, is a new public park, designed by Kathryn Gustafson,The Cuult on theurpark heavily Westgasfabrieck, contaminated sitein Amsterdam, of an old gas is factory. a new public park, designed by Kathryn Gustafson,The soil on pollution the heavily problem contaminated had to be addressedsite of an old and gas the factory. solution could only come from an ecological perspective.The soil Contaminated pollution problem soil could had not to be be removed addressed and and transported the solution elsewhere, could where only come it would from have an causedecological more perspectiv damage.e. Consequently, Contaminated it soil was could decided not to be balance removed the and excavation transported and carry-overelsewhere, volumes:where it would have caused more damage. Consequently, it was decided to balance the excavation and carry- over volumes: to bring new soil to replace the polluted soil, to maintain the existing soil levels around the buildings and to create a new undulating soil with excess material. The placement of the contaminated soil on-site (with the presence of heavy metals and benzene) was the best environmentally economical oriented decision (Figure 16). The remediation process required the presence and the permanence of rainfall infiltration into the soil to maintain current water level in order to preserve the wooden foundation of the historical buildings. So, to preserve the existing ground permeability, the capping solution was suitable only for the impermeable paved areas and the cut and fill process was selected. Moreover as water was cleaned and protected with a barrier from the polluted soil water table, cleansed water started to assume different forms with the shaping of the ground plain: canals, streams, small lakes, splashing fountains and rainwater pools (Figure 17). The water in the park is purified, processed, and stored while the cleansed ground plane has been designed to enrich the visitors’ sensory experience, inviting people to engage in water activities and to learn from natural processes about soil remediation and the temporality of landscape design (Figure 18).

Sustainability 2020, 12, 8840 15 of 25 to bring new soil to replace the polluted soil, to maintain the existing soil levels around the buildings and to create a new undulating soil with excess material. The placement of the contaminated soil on-site (with the presence of heavy metals and benzene) was the best environmentally economical oriented decision (Figure 16). Sustainability 2020, 12, x FOR PEER REVIEW 15 of 25

Figure 16. 16. Gustafson,Gustafson, Porter Porter and and Bowman, Bowman, Cuulturpark Cuulturpa Westgasfabrieck.rk Westgasfabrieck. A new Apublic new park public designed park designedon the heavily on the contaminated heavily contaminated gas factory gas site. factory Contaminated site. Contaminated soil could not soil be could removed not be and removed transported and transportedelsewhere. The elsewhere. placement The of placement the contaminated of the contaminated soil on-site wassoil theon-site best was environmentally the best environmentally economical economicaloriented decision. oriented 2006 decision. Amsterdam. 2006 Amsterdam.

The remediation process required the presence and the permanence of rainfall infiltration into the soil to maintain current water level in order to preserve the wooden foundation of the historical buildings. So, to preserve the existing ground permeability, the capping solution was suitable only for the impermeable paved areas and the cut and fill process was selected. Moreover as water was cleaned and protected with a barrier from the polluted soil water table, cleansed water started to assume different forms with the shaping of the ground plain: canals, streams, small lakes, splashing fountains and rainwater pools (Figure 17). The water in the park is purified, processed, and stored while the cleansed ground plane has been designed to enrich the visitors’ sensory experience, inviting people to engage in water activities and to learn from natural processes about soil remediation and the temporality of landscape design (Figure 18). These themes, presented through built contemporary paradigms, arise as a vision of reconciliation, between the city and exploited soil through natural processes, between the sciences and the arts, in an action of care and responsibility for the present and the future of our cities. This attitude generates virtuous evolutions of sociality, respect and care for places and the acquisition of environmental consciousnessFigure 17. byGustafson, the inhabitants. Porter and They Bowman, acquire, Cuulturpark through the Westgasfabrieck. learning of sustainable Water was landscape cleaned and design, its formsprotected and thewith manifestation a barrier from the of naturalpolluted processes, soil water table, the knowledge cleansed water of thestarted finiteness to assume of thedifferent resources forms with the shaping of the ground plain: canals, streams, small lakes, splashing fountains and and the value of Environmental Ethics in the design of forms. rainwater pools. 2006 Amsterdam. Landscape architecture has a pivotal role in the coexistence of beauty and environmental issues in the interventions. Landscape architecture deeply responds to the need of the present time as These themes, presented through built contemporary paradigms, arise as a vision of it addresses: ecology, remediation, cleansing, environmental infrastructure, social sustainability, reconciliation, between the city and exploited soil through natural processes, between the sciences healthy and productive landscapes. and the arts, in an action of care and responsibility for the present and the future of our cities. This attitude generates virtuous evolutions of sociality, respect and care for places and the acquisition of environmental consciousness by the inhabitants. They acquire, through the learning of sustainable landscape design, its forms and the manifestation of natural processes, the knowledge of the finiteness of the resources and the value of Environmental Ethics in the design of forms. Landscape architecture has a pivotal role in the coexistence of beauty and environmental issues in the interventions. Landscape architecture deeply responds to the need of the present time as it addresses: ecology, remediation, cleansing, environmental infrastructure, social sustainability, healthy and productive landscapes.

Sustainability 2020, 12, x FOR PEER REVIEW 15 of 25

Figure 16. Gustafson, Porter and Bowman, Cuulturpark Westgasfabrieck. A new public park designed on the heavily contaminated gas factory site. Contaminated soil could not be removed and Sustainabilitytransported2020, 12 elsewhere., 8840 The placement of the contaminated soil on-site was the best environmentally16 of 25 economical oriented decision. 2006 Amsterdam.

Figure 17.17. Gustafson, Porter and Bowman, Cuulturpark Westgasfabrieck. Water was cleaned and and protectedprotected withwith aa barrierbarrier from the polluted soil water table, cleansed water started to assume different different formsforms withwith thethe shapingshaping ofof thethe groundground plain:plain: canals,canals, streams,streams, smallsmall lakes,lakes, splashingsplashing fountainsfountains andand Sustainabilityrainwaterrainwater 2020 pools.pools., 12, x FOR 200 2006 6PEER Amsterdam. REVIEW 16 of 25

These themes, presented through built contemporary paradigms, arise as a vision of reconciliation, between the city and exploited soil through natural processes, between the sciences and the arts, in an action of care and responsibility for the present and the future of our cities. This attitude generates virtuous evolutions of sociality, respect and care for places and the acquisition of environmental consciousness by the inhabitants. They acquire, through the learning of sustainable landscape design, its forms and the manifestation of natural processes, the knowledge of the finiteness of the resources and the value of Environmental Ethics in the design of forms. Landscape architecture has a pivotal role in the coexistence of beauty and environmental issues in the interventions. Landscape architecture deeply responds to the need of the present time as it addresses: ecology, remediation, cleansing, environmental infrastructure, social sustainability, healthy and productive landscapes.

FigureFigure 18. 18. Gustafson, Porter and Bowman, Cuulturpark Westgasfabrieck. The The water is purified,purified, processed,processed, andand storedstored andand itit enrichesenriches thethe visitors’visitors’ sensorysensory experience,experience, inviting people to engage in waterwater activitiesactivities andand toto learn from naturalnatural processes about soil remediation and the history of the site. 20062006 Amsterdam.Amsterdam.

5.5. Third Part:Part: Soil Design as a Space ofof ResilienceResilience toto overover Flow:Flow: NewNew UnstableUnstable UrbanUrban LandscapesLandscapes ClimateClimate change change and and exceptional exceptional events events of flooding of flooding and atmospheric and atmospheric precipitation precipitation have profound have eprofoundffects on soileffects quality. on soil Erosion, quality. pollution Erosion, due pollution to clogging due of to water clogging management of water systems,management contamination systems, duecontamination to flooding, due damage to flooding, due to soil damage sealing, due are to the soil most sealing, evident are e ff theects most of these evident mutations. effects of these mutations.These phenomena are now increasing in number and intensity and the urban environment is certainlyThese phenomena a scenario particularly are now increas frailing to thesein number events, and and intensity is exposed and tothe produce urban environment risks. From is a Europeancertainly a Environment scenario particularly Agency (EEA) frail to document: these events, “A wider and is literature exposed review to produce suggests risks. that From heavy a precipitationEuropean Environment events have Agency become more(EEA) intense document: and more“A wider frequent literature in Europe review on average, suggests but that there heavy are importantprecipitation diff erencesevents have across become regions, more seasons, intense time and periods, more heavyfrequent precipitation in Europe indices on average, and underlying but there datasets.are important A recent differences study has across shown regions, that the seasons, number time of periods,days with heavy very precipitation heavy precipitation indices over and Europeunderlying has increaseddatasets. A on recent average study by has about shown 45% that (for the the number period 1981–2013 of days with compared very heavy with precipitation 1951–1980). over Europe has increased on average by about 45% (for the period 1981–2013 compared with 1951– 1980). Studies generally agree that heavy precipitation has become more intense in northern and north-eastern Europe since the 1950s, even though not all changes are statistically significant. Different studies and indices show diverging trends for south-western and southern Europe” [27] (8). The technique generally used to deal with these situations was the construction of lamination tanks or expansion tanks that worked to accommodate large quantities of water in order to avoid the disposal system clogging. The idea was to store rainwater in these buffer areas to postpone their disposal until the drainage system recovered its seating capacity. This implied the belief that water was an unlimited resource, while today these systems are surpassed by a design that starts from the principle of preserving and using rainwater. The prerequisite of this approach is the separation of white water from waste water which allows the use of rainwater without it being contaminated by sewage water and prevents the sudden flow of rainwater from surpassing the capacity of the purifiers, producing uncontrolled spills.

5.1. The New Trends The turning point, in the context of a changed attitude towards natural resources, is mainly due to the concept of landscape approach as a method [28] (9–11), and of integrated design brought forward in the last decades in American studies on landscape and in the many contributions of different disciplines. This principle, starting from McHarg [8], continuing with the development of Corner on Landscape Urbanism [21], and up to Urban Ecological Design [29], spreads the seeds of a

Sustainability 2020, 12, 8840 17 of 25

Studies generally agree that heavy precipitation has become more intense in northern and north-eastern Europe since the 1950s, even though not all changes are statistically significant. Different studies and indices show diverging trends for south-western and southern Europe” [27] (p. 8). The technique generally used to deal with these situations was the construction of lamination tanks or expansion tanks that worked to accommodate large quantities of water in order to avoid the disposal system clogging. The idea was to store rainwater in these buffer areas to postpone their disposal until the drainage system recovered its seating capacity. This implied the belief that water was an unlimited resource, while today these systems are surpassed by a design that starts from the principle of preserving and using rainwater. The prerequisite of this approach is the separation of white water from waste water which allows the use of rainwater without it being contaminated by sewage water and prevents the sudden flow of rainwater from surpassing the capacity of the purifiers, producing uncontrolled spills.

5.1. The New Trends The turning point, in the context of a changed attitude towards natural resources, is mainly due to the concept of landscape approach as a method [28] (pp. 9–11), and of integrated design brought forward in the last decades in American studies on landscape and in the many contributions of different disciplines. This principle, starting from McHarg [8], continuing with the development of Corner on Landscape Urbanism [21], and up to Urban Ecological Design [29], spreads the seeds of a new approach to the design of the contemporary city in an ecological vision. This vision—readily accepted in northern Europe first, with consolidated Danish and Dutch experiences from Jan Gehl and Aldo Van Eyck, up to the latest West8 or SLA architectural labs, and after in France by the actors and followers of the Versailles school: Corajoud [30], Clement e Donadieu [31]—has been elaborated upon within the European landscape culture, developing an original framework due to the long tradition in urban planning and public spaces. In recent decades, therefore, there has been a progressive change of direction [32]. In managing the relationship between the city and water instead of simply protecting the territory from floods or facing the sudden rains trying to free the soil of the large amount of rainwater, strategies are experimented to allocate the presence of this water on the ground surface and then release it in the soil when useful. Managing the overflow through flow regulation and rainwater conservation, allows their reuse for climate change effect mitigation and in the treatment of heat islands. The long-standing attention paid to the presence of plants in the urban landscape and to the care of the public space seem to have had a favorable evolution today in the contamination with these trends and with the most recent studies for a sustainable city [33,34]. It is only by introducing and multiplying ecosystem services in the urban fabric that we can improve the urban condition but, at the same time, it is not only by bringing nature back to the city that a sustainable city is built: it is above all by reconnecting the city with its natural context, its original landscape context [35]. It is therefore not just a matter of greening cities, of strengthening ecological networks or of designing gardens, but action is to be taken to insert real fragments of nature—efficient ecosystems—into the urban fabric. In this way, while previously limited in parks, nature spreads now in the urban fabric with green and blue ramifications and nets favorable to the circulation of animal and vegetable species. When building biological corridors, maintaining areas in hay, reconstructing wetlands, a strict delimitation between city and nature is no longer applicable at the scale of the city. A new water management strategy is therefore congruent with this different vision of the relationship between city and nature. Water and the related soil projects are essential components of context-based projects because they use existing resources that would otherwise be dispersed and, by introducing the time variable with the creation of adaptive landscapes, they allow the planning of an incremental evolution of places. This is the basis for next generation landscape urbanism [30]. The project of wet or water sensitive landscapes is an essential tool for a sustainable city and for the daily as well as for the exceptional management of events related to overflow; it is a project that Sustainability 2020, 12, 8840 18 of 25 expresses itself through the soil project, proposing adaptive landscapes, which have the ability to retain and conserve water, to act as a porous substrate, to manage rainwater and flooding, transforming them from risk factors to resources. Two domains of a different relationship between city and water:

1. The management of floods with measures to minimize the impacts of rising water on the habitat. 2. The management of rainwater by giving it back the role of a resource.

In each of the two cases it is a question of accepting the issued water and, rather than rejecting it, keeping and it in place.

5.2. Flood Management to Minimize the Impacts of Rising Water on the Habitat Flood management adopting measures to minimize the impacts of rising water on the habitat in new projects implies design choices and the analysis of the acceptability of their degree of risk. As the Urban Strategy Projects Observation Platform (POPSU) document states: “urbanization of wetlands is a complex line of thought” which must seek to bring harmony “between risk prevention plans that are part of an objective of protection of property and people and sustainable urban and landscape development” [36]. As far as new urban projects are concerned, the main theme is to ensure on site risk management by designing urban, architectural and landscape systems that, through the soil project, integrate water Sustainability 2020, 12, x FOR PEER REVIEW 18 of 25 into the urban organization. HafenCity in Hamburg [37] is perhaps one of the best-known cases but, forbut, other for other aspects, aspects it appears, it appears a less a innovative less innovative project. project The city. The rises city and rises defends and defends itself from itself the from water; the thewater; new the neighborhood new neighborhood that connects that connects the city the with city its riverwith hasits river been has organized been organized on different on levelsdifferent to ensurelevels to at ensure the same at timethe same defense time from defense floods from and floods access and to the access river to by the building river by a city building with a a heightened city with a urbanity.heightene Ond urbanity. the river On there the isriver a series there ofis floatinga series of elements floating that elements absorb that the absorb daily trendthe daily of the trend tides of whichthe tides varies which about varies three about meters. three These meters. floating These piers floating are places piers are for walkingplaces for and walking for bringing and for boats bringing into theboats city; into higher the city; up ishigher the level up is of the the level old dockof the warehouses old dock warehouses where today where there today are cyclethere pathsare cycle and paths long pedestrianand long pedestrian paths at sea; paths three at meterssea; three higher meters still, higher there arestill only, there the are entrances only theto entrances the houses, to the the houses, streets andthe streets the bridges; and the and bridges; finally, and even finally, higher even up, higher a system up, of a walkwayssystem of connectingwalkways connecting the new buildings the new whichbuildings most which of the most shops of overlookthe shops (Figure overlook 19). (Figure 19).

FigureFigure 19.19. Hafencity:Hafencity: the floatingfloating piers; higher up, the level of the oldold docksdocks wherewhere todaytoday therethere areare cyclecycle pathspaths and long long pedestrian pedestrian paths paths at at sea; sea; three three meters meters higher higher still still,, the the entrances entrances to the to thehouses, houses, the thestreets streets and and the thebridges; bridges; even even higher higher up, up, a system a system of walkways of walkways connecting connecting the thenew new buildings. buildings.

Figure 20. Hammarby: the new district recovers the riparian areas, purifies the waters of the lake with phyto-depuration systems and builds a network of canals and green corridors for rainwater that crosses private and public spaces of the neighborhood and connects both the woods and lake ecosystems.

Sustainability 2020, 12, x FOR PEER REVIEW 18 of 25 but, for other aspects, it appears a less innovative project. The city rises and defends itself from the water; the new neighborhood that connects the city with its river has been organized on different levels to ensure at the same time defense from floods and access to the river by building a city with a heightened urbanity. On the river there is a series of floating elements that absorb the daily trend of the tides which varies about three meters. These floating piers are places for walking and for bringing boats into the city; higher up is the level of the old dock warehouses where today there are cycle paths and long pedestrian paths at sea; three meters higher still, there are only the entrances to the houses, the streets and the bridges; and finally, even higher up, a system of walkways connecting the new buildings which most of the shops overlook (Figure 19).

Sustainability 2020, 12, 8840 19 of 25

Noteworthy but in countertrend is the fact that vegetation has a very marginal or no role at all to play and therefore the relationship with water is essentially delegated to its mineral parts of the public space that protect and return excess water to the river. If HafenCity is well known, the Hammarby district in Stockholm is now a reference point for a sustainable city design. Designed in continuity with the pre-existing environmental system (woods and lake), the new district recovers the riparian areas, purifies the waters of the lake with phyto-depuration systems and builds a network of canals and Figure 19. Hafencity: the floating piers; higher up, the level of the old docks where today there are green corridors for rainwater that crosses private and public spaces of the neighborhood and connects cycle paths and long pedestrian paths at sea; three meters higher still, the entrances to the houses, the both the woods and lake ecosystems (Figure 20). streets and the bridges; even higher up, a system of walkways connecting the new buildings.

Figure 20. Hammarby: the new new district district recovers the riparian areas, purifiespurifies the waters of the lake with phyto-depurationphyto-depuration systems systems and and builds builds a network a network of canals of canals and green and green corridors corridors for rainwater for rainwater that crosses that privatecrosses and private public and spaces public of the spaces neighborhood of the neighborhood and connects and both connect the woodss both and the lake woods ecosystems. and lake ecosystems. In the same trend, is the project to transform the city of Lodz [38] into a Water Sensitive City [39]. Most of Lodz’s urban waterways were transformed into underground canals in the past; this, combined with the high sealing of the soils, has exposed the city to numerous floods during the recent violent storms having numerous the consequences for the soil and the water system. As part of the European program Sustainable Water Management Improves Tomorrows Cities Health (SWITCH), a strategy for adapting the city to water has been implemented, based on the principle of green and blue networks. Urban-scale initiatives have been planned to recover the waterways and revitalize the riparian areas, to create green spaces and corridors to collect and manage rainwater, to condition urban planning to the system of green and blue networks (Figure 21). Currently, in this context, there is a pilot project and an integrated approach to design led by a team, where all the actors involved in the management of water resources and ecosystem services are represented and have been carried out. The urban project for Vitry gare de Seine by Germe & Jam in France along the Seine is more radical in building a water-resilient environment. It has as reference the Flood of One Hundred Years and the issue of flooding risk is at the center of the design of the public space and the urban fabric. (Figures 22 and 23). In Vitry, an artificial floor consisting of a network of elevated paths connected by walkways allows the connection of urban services and the entrances of residential buildings in the event of an extraordinary flood, while public spaces are designed to adjust to ordinary floods and violent rains. Sustainability 2020, 12, x FOR PEER REVIEW 19 of 25

Noteworthy but in countertrend is the fact that vegetation has a very marginal or no role at all to play and therefore the relationship with water is essentially delegated to its mineral parts of the public space that protect and return excess water to the river. If HafenCity is well known, the Hammarby district in Stockholm is now a reference point for a sustainable city design. Designed in continuity with the pre-existing environmental system (woods and lake), the new district recovers the riparian areas, purifies the waters of the lake with phyto-depuration systems and builds a network of canals and green corridors for rainwater that crosses private and public spaces of the neighborhood and connects both the woods and lake ecosystems (Figure 20). In the same trend, is the project to transform the city of Lodz [38] into a Water Sensitive City [39]. Most of Lodz’s urban waterways were transformed into underground canals in the past; this, combined with the high sealing of the soils, has exposed the city to numerous floods during the recent violent storms having numerous the consequences for the soil and the water system. As part of the European program Sustainable Water Management Improves Tomorrows Cities Health (SWITCH), a strategy for adapting the city to water has been implemented, based on the principle of green and blue networks. Urban-scale initiatives have been planned to recover the waterways and revitalize the riparian areas, to create green spaces and corridors to collect and manage rainwater, to condition urban planning to the system of green and blue networks (Figure 21). Currently, in this context, there is a pilot project and an integrated approach to design led by a team, where all the actors involved in Sustainability 2020, 12, 8840 20 of 25 the management of water resources and ecosystem services are represented and have been carried out.

Figure 21. Lodz: urban-scale initiatives have been planned to recover the waterways and revitalize SustainabilityFigure 21. 2020Lodz:, 12, xurban-scale FOR PEER REVIEW initiatives have been planned to recover the waterways and revitalize20 the of 25 riparianthe riparian areas, areas, to create to create green green spaces spaces and corridors and corridors to collect to collect and manage and manage rainwater, rainwater, to condition to condition urban urban planning to the system of green and blue networks. planning to the system of green and blue networks.

The urban project for Vitry gare de Seine by Germe & Jam in France along the Seine is more radical in building a water-resilient environment. It has as reference the Flood of One Hundred Years and the issue of flooding risk is at the center of the design of the public space and the urban fabric. (Figures 22 and 23) In Vitry, an artificial floor consisting of a network of elevated paths connected by walkways allows the connection of urban services and the entrances of residential buildings in the event of an extraordinary flood, while public spaces are designed to adjust to ordinary floods and violent rains. The interesting element of this project is that by allowing the water to expand in the gardens and under the buildings, Germe & Jam managed to avoid the construction of blind walls at the urban routes level as happened for instance in Hafencity. The network of elevated paths can also be used by service vehicles in order to allow, in the event of a flood, an organized and calm removal of the inhabitants.

FigureFigure 22. Vitry:22. Vitry: the the neighborhood neighborhood projectproject (left) (left) and and the the accessibility accessibility during during the flood the flood (right). (right ).  © Germe&Jam. Germe&Jam

The interesting element of this project is that by allowing the water to expand in the gardens and under the buildings, Germe & Jam managed to avoid the construction of blind walls at the urban routes level as happened for instance in Hafencity. The network of elevated paths can also be used by service vehicles in order to allow, in the event of a flood, an organized and calm removal of the inhabitants.

Figure 23. Vitry: a network of elevated paths connected by walkways allows the connection of urban services and entrances of residential buildings in the event of an extraordinary flood, while public spaces are designed to adjust to ordinary floods and violent rains.  Germe&Jam

5.3. The Management of Rainwater Giving Them Back the Role of Resource There are also very innovative interventions in the domain of the rainwater management; previously considered as something to be disposed of, today rainwater is transformed into a resource, both in “normal” and in exceptional conditions. A resource to be retained and organized by capitalizing upon it, and then to be used in irrigation, in mitigating the effects of climate change, and in the treatment of urban heat islands [40]. The number of innovative projects is increasing and the majority are oriented towards using the urban soil surface for the temporary collection of water. The water collected, when possible, is transformed into a temporary leisure resource and, at the same time, providing a careful filtering capacity and a permeability of the soils, can be used for watering or slowly released into nature. There are two types of projects: places with a prevalence of plants,

Sustainability 2020, 12, x FOR PEER REVIEW 20 of 25

SustainabilityFigure2020, 1222., 8840 Vitry: the neighborhood project (left) and the accessibility during the flood (right). 21 of 25  Germe&Jam

Figure 23. Vitry: a network of elevated paths connected by walkways allows the connection of Figure 23. Vitry: a network of elevated paths connected by walkways allows the connection of urban urban services and entrances of residential buildings in the event of an extraordinary flood, while services and entrances of residential buildings in the event of an extraordinary flood, while public public spaces are designed to adjust to ordinary floods and violent rains.  Germe&Jam spaces are designed to adjust to ordinary floods and violent rains. © Germe&Jam.

5.3.5.3. TheThe ManagementManagement ofof RainwaterRainwater GivingGiving ThemThem BackBack thetheRole Role ofofResource Resource ThereThere are are alsoalso veryvery innovative innovative interventions interventions inin the the domain domain of of the the rainwater rainwater management; management; previouslypreviously considered considered as as something something to to be be disposeddisposedof, of, todaytoday rainwaterrainwater isis transformedtransformed intointo aa resource,resource, bothboth in in “normal” “normal and” and in exceptional in exceptional conditions. conditio A resourcens. A resource to be retained to be and retained organized and by organized capitalizing by uponcapitalizing it, and upon then it, to and be usedthen into be irrigation, used in irrigation, in mitigating in mitigating the effects the of effects climate of change,climate change and in, theand treatmentin the treatment of urban of heat urban islands heat [islands40]. The [40 number]. The number of innovative of innovative projects isprojects increasing is increasing and the majority and the aremajority oriented are towardsoriented usingtowards the us urbaning the soil urban surface soilfor surface the temporary for the temporary collection collection of water. of Thewater. water The collected,water collected when, possible,when possible, is transformed is transformed into a temporaryinto a temporary leisure leisure resource resource and, at and, the at same the time,same providingtime, providing a careful a careful filtering filtering capacity capacity and a and permeability a permeability of the of soils, the soils, can becan used be used for wateringfor watering or slowlyor slowly released released into into nature. nature. There There are are two two types types of of projects: projects: places places with with aa prevalenceprevalence ofof plants,plants, parks or natural areas integrated into the urban fabrics which, in the soil and vegetation arrangement and in its design and use, integrate temporarily humid landscapes, and small-sized mineral places, squares, capable of holding rainwater, integrating the overflow with the creation of accessible pools and fountains. In the first group are the Urbanwater Parc des Docks in Saint Ouen, the Agence Ter’s Parc Trapeze in Boulogne Billancourt, and the landscape project for the new Rives de la Haute Deûle district of the atelier de paysage Bruel Delmar. In the Parc des Docks the rainwater of the surrounding neighborhood is collected and held in the open by a system of depressions and reservoirs where it is treated by means of a plant filtration device. In the absence of rain these green spaces have a landscape function, and, in case of rain, they are animated by the variability of the water, water used to irrigate the park and vegetable gardens. Moreover, the Trapéze Park in Boulogne Billancourt is at the heart of the district’s rainwater management system. The permeability of its soils and the storage of water in hollow gardens filters all rainwater which is then partially recovered in a basin to be reused for irrigation (Figure 24). This water management system allows for a great diversity of plants and therefore a very differentiated management of space. The park is a true ecological niche between the river and the green spaces of the district and is designed to be used even in situations of great overflow (Figure 25). Sustainability 2020, 12, x FOR PEER REVIEW 21 of 25

parks or natural areas integrated into the urban fabrics which, in the soil and vegetation arrangement and in its design and use, integrate temporarily humid landscapes, and small-sized mineral places, squares, capable of holding rainwater, integrating the overflow with the creation of accessible pools and fountains. In the first group are the Urbanwater Parc des Docks in Saint Ouen, the Agence Ter’s SustainabilityParc Trapeze2020 in, 12 Boulogne, 8840 Billancourt, and the landscape project for the new Rives de la Haute 22Deûle of 25 district of the atelier de paysage Bruel Delmar.

Figure 24.24. TrapézeTrapéze park in Boulogne Billancourt is at the heart of the district’s rainwater management system. The permeability of its soils and the storage of water in hollow gardens filtersfilters all rainwater which isis thenthen partiallypartially recoveredrecovered inin aa basinbasin toto bebe reusedreused forfor irrigation.irrigation.

TheIn the landscape Parc des project Docks for the the rainwater Rives de of la Hautethe surrounding Deûle district neighborhood is based on localis collected rainfall. and Its fulcrumheld in isthe an open aquatic by a garden system fed of withdepressions the rainwater and reservoirs falling on where roofs, it roads is treated and public by means spaces. of a The plant water filtration flows firstdevice. into In the the small absence valleys of rain that these border green the space islets,s thenhave into a landscape larger canals function and, finally and, in arrives case of purified rain, they in theare aquaticanimated garden by the which variability is sized of basedthe water on rainfall, water butused also to actsirrigate as a the catchment park and area vegetable in case ofgardens. floods. Moreover,Always the aimed Trapéze at the Park collection in Boulogne and conservation Billancourt of israinwater, at the heart the second of the group district of’s realizations rainwater aremanagement smaller-sized, system. punctual The permeability interventions of its where—as soils and itthe happens storage forof water Tåsinge in hollow Square gardens and St. Kiensfilters squareall rainwater or Hans which Tavens is then park partially of SLA in recovered Copenhagen—the in a basin public to be spacereused is for a changing irrigation artificial (Figure landscape. 24). This Inwater these management projects, the system shape ofallows the mineral for a great soil diversi is deformedty of plants to hold and and therefore conserve a excessvery differentiated rainwater in accessiblemanagement pools of andspace. fountains The park which, is a true in the ecological absence niche of rain, between become the part river of theand mineral the green public spaces space of again,the district combining and is thedesigned construction to be used of a functionallyeven in situati resilientons of landscapegreat overflow with the(Figure creation 25). of new spaces for leisure.The landscape project for the Rives de la Haute Deûle district is based on local rainfall. Its fulcrumThese is an projects aquatic are garden the intelligent fed with manifesto the rainwater of the falling felicitous on roofs, combination roads and of good public soil spaces. and water The resourcewater flows management, first into the the small mending valleys of that the urbanborder fabric the islets, and then landscape into larg context,er canals and and the finally quality arrives of the publicpurified space. in the In aquatic this context garden the themewhich of is overflow sized based management on rainfall is anbut integral also acts part as of a thecatchment urban planning area in andcase organization,of floods. and the urban fabric is able to absorb extreme natural events without being damaged. These interventions are representative of the various knowledge bases in the field, from which it is clear that the projects in Northern Europe and the first French projects have treated rainwater with often multifunctional works mainly aimed at protecting the city from water. This trend—especially in France thanks to the new water law that imposes a very strict limit on the elimination of rainwater—provides a lot of space for its storage in the city. Surfaces found in the public space which are, however, returned to the city in the form of changing wet landscapes. One of the effects of the management of rainwater on the surface is therefore the slow change of urban landscapes, important from the point of view of the ecosystem, as something perhaps to be monitored carefully to avoid the wrong homologation of urban spaces. Sustainability 2020, 12, 8840 23 of 25 Sustainability 2020, 12, x FOR PEER REVIEW 22 of 25

Figure 25. Trapéze park: different levels of rainwater and flood. Figure 25. Trapéze park: different levels of rainwater and flood. 6. Discussion Always aimed at the collection and conservation of rainwater, the second group of realizations are smallerDue to-sized, environmental punctual disasters, interventions resources where exploitation,—as it happens loss for in Tåsinge biodiversity Square and and fast St. climate Kiens change,square or which Hans are Tavens largely park caused of by SLA human in Copenhagen action, the importance—the public of space healthy is natural a changing environments artificial haslandscape. increased. In these Paradoxically, projects, the waste shape and of pollution, the mineral especially soil is deformed in the case to of hold wet soil,and canconserve be potential excess resourcesrainwater forin accessible the well-being pools ofand the fountains environment which, in in which the absence we live. of rain, The become prolific landscapepart of the ecologymineral andpublic ecological space again, restoration combining disciplines the construction significantly of a functionally influence landscape resilient landscape architecture with practice the creation and theory.of new Forward-thinkingspaces for leisure. ecological and environmental planning and landscape architectural practices, however,These can projects diversify are theirthe intelligent scope, environmental manifesto of etheffectiveness felicitous and combination enduring of resilience. good soil and water resourceThe selectedmanagement, projects the of mending this essay of are the exemplary urban fabric cases and of landscape interventions context, on degraded—or and the quality atrisk of the of degradation—soilspublic space. In this that context have managed the theme to ofreinforce overflow the management ecosystem services is an and integral transform part of those the places urban intoplanning places and for organization, the community. and Inthe three urban di fffabricerent is types able of to places: absorb formerextreme landfills, natural industrialevents without sites, andbeing urban damaged. locations These threatened interventions by overflow, are representativ the strategice of design the various of wet andknowledge hydric landscapes bases in the has field the, soilfrom as which the key it subject.is clear Thisthat the shows projects how riskin Northern can become Europe a resource and the while first the French environmental projects have damage treated can rainwater with often multifunctional works mainly aimed at protecting the city from water. This

Sustainability 2020, 12, 8840 24 of 25 be remedied. Fundamental elements in the design strategies were the integration of different disciplines and principles in the remediation process built by design: context based projects, fostering Public Nature, sustaining Environmental Ethics and supporting Hypernature. The intervention techniques are different from places to place, to cleanse and to prevent pollution caused by floods to preserve environmental qualities: from soil washing, to the creation of new resilient urban landscapes. The research in this field arises as a vision of reconciliation, between the cities and the exploited soils through the activation of natural processes, between the sciences and the arts, in an action of care and responsibility for the present and the future of our cities and our living environment. As evidenced by both the continuous evolution of logic and techniques, this discussion is a fertile and complex field in which we face the necessary conjunction between the aesthetic experience, the scientific research and ethical responsibility.

Author Contributions: The authors of the essay wrote the entire content of the article together. F.M. wrote paragraph 3, I.C. paragraph 4 and L.V.F. paragraph 5. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Conflicts of Interest: The authors declare no conflict of interest.

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