All & cover by Jessie Tang

By Jessie Tang B. Sc, Architecture and Sustainable Design (2015) Submitted to the Architecture and Sustainable Design Pillar in Partial Fulfillment of the Requirements for the Degree of Master of Architecture at the Singapore University of Technology and Design August 2017 Thesis Advisor: Sam Conrad Joyce

ABSTRACT Due to rapid urbanisation, man-made canals are constructed and remains as a crucial infrastructural provision in Singa-

pore in both mitigating potential flood situations and also as a important stormwater collection passage. The current state

of the concrete canals detaches the society from accessing

the water resource and there is a shift in the initial utilitarian

approach on dealing with our waterways. Upon investigating and evaluating current canal states and practices, and studying precedents of successful waterway restoration, ways of further enhancing the interaction between the users and waterways are discussed. This thesis aims to investigate and integrate architectural and

natural strategies through the use of phytoremediation with

water systems by proposing a new canal system that i) attract

and engage audiences and ii) provides a learning experience that could strengthen the relationship between Singapore and its waterbodies, enhancing the value of water.

1 INTRODUCTION What are waterways Singapore - History` - Four National Taps - Climate - Waterways - Land & Water Development - Paradigm Shift

URBAN WATER SPACES

Precedents Current Strategies Analysis

3 NATURAL STRATEGIES

Cleansing Strategy: Phytoremediation - Phytosequestration - Rhizodegradation - Phytohydraulics - Phytoextraction - Phytovolatilization - Phytodegradation

Application

Plant Species Summary

PROPOSED SITE Site Selection - Bukit Timah - Bedok - Chua Chu Kang Chosen Site Site Analysis

CASE STUDIES Educational Facilities

6 DESIGN Building Design Development - Circulatory Planning - Programmatic Planning - Section - Roof Design Phytoremediation Integration - Water Level - Water Cleansing - Sankey Diagram

7 REFERENCES

WHAT ARE WATERWAYS? Since times immemorial, water resources has been taking center stage in urban developments. The origin and growth of cities has been long connected with water sources. Proximity to water resources greatly affected how early settlements and later cities (Ponting, 2011). The influence of water continues today and can be observed through the geographic distribution of modern major cities, which are generally located along riverside, coastal areas and other waterfronts. In the management of water in a city, waterways are â&#x20AC;&#x153;managed as a resource for human benefit, including water supply, flood mitigation, disposal of wastewater and minimization of diseaseâ&#x20AC;? (Findlay and Taylor, 2006). For these reasons, there is significant increase in concretization of canals due to urbanization, and attempts to control the rivers and stormwaters from threatening our build environment along the riverside (Check, 1997). The exponential population growth and growth of cities increased the intensity of urban land-use, and resulted in undesirable pressures on the urban water systems (Baird, 2009)

1 Increased stormwater surface runoff Urban developments involves large surfaces with hard surfaces like cement, this results in the decrease in infiltration and percolation of water into the ground. For the same amount of rain, the amount of surface runoff is greater. This increased volume and intensity of surface

runoff increase the threat of flash floods, where under sudden and intensive rainfall, the capacity of drainage systems might exceed. Despite extensive efforts to address this threat, within the past five years, Singapore experienced multiple major urban floods. 2 Decreased water quality In the Urban environment, as hard surfaces are impeameable, soils are prevented from naturally filtering and controling the flow of pollutants into the water systems. The increased runoff volume also washes pollutants faster away. Urban runoffs are all activities that significantly decrease water quality in this and other ways. 3 Degradation of biodiversity Decreased water quality affects the flora and fauna. Construction of canals also causes a loss of certain ecosystems as during the development, the native biodiversity lost their homes and habitat. These various forms of environmental effects as illustrated above have been faced by Singapore. In facing the impacts of urbanization, the immediate solution to deal with stormwater was to plan waterways and construct concrete canals. The main objective was to direct and channel stormwater as fast as possible out of the city before water levels rise to a point where it will affect the city and its people.

Figure 1 Urban Stormwater Runoffs (from https://www.pub.gov.sg).

Figure 2 Storm hydrograph showing the difference in peak runoff between an urbanised area and a pre-development site. (from https://www.pub.gov.sg).

SINGAPORE’S PUBLIC WATER SUPPLY In 1819, Sir Stamford Raffles of the British East India Company (EIC) founded Singapore. Raffles turned singapore into a free port for entropy trading due to its strategic location along the Straits of Malacca. Singapore’s port became one of the most important ports in the world in the late eighteen century. Singapore River was the island’s main trading area. The city’s development expanded outwards from the banks of Singapore River and formed the Central area. The central area suffered from issues of overcrowding after decades of urban development and lack of planning. After Singapore attained self-governance in 1959, population density increased to 2500 person/ha and many people were living in unkempt conditions without water, sanitation or any form of public health provision (PUB, 1972). As the need to improve the population’s quality of life and increase their sense of ownership was key to nation-building, People’s Action Party (PAP), the ruling party developed a scheme to to resolve the disparities in the standard of living of the population in urban and rural areas. Problems and issues such as lack of housing, overcrowding, basic amenities and services, transportation and hospitals had to be addressed. PRE-INDUSTRIAL

1850

1858

Lee Kuan Yew, Singapore’s first Prime Minister (1965–1990) focused on opportunities and schemes to green Singapore by reducing pollution and cutting business costs. He contributed to the well-developed network of linked greenways and parks as well as the successful cleanup of the Singapore River between 1977 and 1986. The all-rounded methodology that dealt with urban development, environmental management, sustainability and economic opportunity proved that intimate coordination between government agencies and different sectors in Singapore is required. The Public Utility Board (PUB) was established in 1963, as part of the holistic approach which Lee Kuan Yew envisioned. It was set up initially for the provision of electricity, water and piped gas. After the Singapore River restoration project, the development of drainage, canals and sanitary sewer systems, PUB started the Four National Taps water management strategy.

1863

Figure 3 The development of water drainage.

1890

1912

Figure 4 The PUB approach to closing water loop (from https://www.pub.gov.sg/about/whatwedo).

Singapore takes a all-round method in managing its water system, which covers the entire water cycle through PUB. PUB termed this approach closing the loop and the philosophy is summarized in Figure 4. The core element of the closing the loop philosophy is the Four National Taps, or the four water supply sources for Singapore. 11

CLIMATE AND GEOGRAPHY Singapore is a small island nation-state located at the southern end of the Malaysian Peninsula. It has a total area of 715.8 km2, with an east–west length of only 49 km and a north–south length of 25 km. The third most dense country in the world after Macau and Monaco, Singapore has a population density of 7257 people/km2. In comparison, the United States ranks 172nd with 34.3 people/km2 and Canada ranks 220th with 3.8 people/km2. Singapore’s per capita GDP in 2011 (adjusted for purchasing power parity and based on current international dollars) was higher, at $60688 than either the United States ($48112) or Canada ($40370) according World Bank statistics The climate of Singapore is classified under the Koppen system as a tropical rainforest (Af) with no true dry season. Annual mean rainfall is approximately 2 343 mm and annual mean temperature is 27 °C. Singapore rains an average of 178 days of the year. Most of the rain events are heavy and usually accompanied by thunder. In keeping with its tropical rainforest classification, the mean number of days/month with rain ranges between 11 and 19, and the minimum number of rain days per month is in the range 1 to 3 (NEA). Although Singapore has no change in seasons, Singapore’s climate varies due to the influence of two monsoon seasons separated by inter-monsoonal periods. 12

Northeast Monsoon : December to early March Southwest Monsoon : June to September Heavy rainfall in Singapore are usually caused by: i) Monsoon surges during the Northeast Monsoon flow; ii) Sumatra squalls, an organised line of thunderstorms developed over Sumatra or Straits of Malacca travelling eastward across Singapore; iii) strong surface heating and afternoon sea breeze circulation causing afternoon and evening thunderstorms.

Figure 5 Rainfall data from 1980 to 2012 showing a trend towards higher rainfall intensities (from https://www.pub.gov.sg).

Figure 6 Average number of rain days per month (19822016). (from http://www.weather.gov.sg/climate-climate-of-singapore/).

Figure 7 Monthly rainfall for Singapore (mm) (1982-2016). (from http://www.weather.gov.sg/climate-climate-of-singapore/).

Figure 8 Topographical map of Singapore (from https://www.pub.gov.sg).

Figure 9 Annual average rainfall distribution (1982-2016) (from http://www.weather.gov.sg/climate-climate-of-singapore/).

Figure 10 Hourly variation of rainfall for each month (1982-2016) (from http://www.weather.gov.sg/climate-climate-of-singapore/).

THE FOUR NATIONAL TAPS

1 Water Imports from Malaysia Singapore has two water agreements with. They were consecutively signed in 1961 and 1962, the first agreement expired in 2011 and the second is expiring in 2061. The second agreement currently provides up to 250 mgd. The water is imported to Singapore via a pipeline located at the causeway between Singapore and Johor, Malaysia. Water import agreements between Singapore and Malaysia can be traced back to 1927. Recently, a new round of water negotiations began in 1998. By 2003, Singapore was motivated to looking for alternative water sources, which includes importing from Indonesia, as the negotiations with Malaysia ended without undesirably. As 2061 approaches, Singapore was forced to source and diversify its technologies to be self sufficient in its water supply.

Figure 11 Location of Linggiu Reservoir

Figure 12 NEWater and Desalination Plants

2 NEWater NEWater is the product of a process of water reclamation where used water undergoes four steps to become clean water again. a Conventional water treatment The first step is the usual water treatment process where wastewater is treated to globally recognised standards. b Microfiltration Microfiltration is the second step and involves using membranes to filter out suspended solids, colloidal particles, disease-causing bacteria, viruses and protozoan cysts. After this stage, the contents of water only consist of dissolved salts and organic molecules. c Reverse osmosis Reverse osmosis stage involves a

semi-permeable membrane that traps bacteria, viruses, dissolved salts, heavy metals, etc. Only very minute molecules like water can pass through this membrane. d Ultraviolet disinfection Following reverse osmosis, the water is said to have become ultra-clean. The ultraviolet disinfection is a extra safety measure that ensures the deactivation of any residual micro-organisms. This is the final stage of the NEWater production process. The waterâ&#x20AC;&#x2122;s pH balance is restored using chemicals before NEWater is ready for consumption. NEWater is currently contributing mainly as a alternative for water consumption in industries. A small percentage is mixed into reservoirs for indirect potable use. 17

Figure 13 The NEWater Treatment process (from https://www.pub.gov.sg/).

Figure 14 The desalination process (from https://www.pub.gov.sg/).

3 Desalination Desalination was once a costly alternative for water scarce countries, desalination technology has advanced dramatically over the past decade (Bremere et al. 2001; Khawaji et al. 2008; Greenlee et al. 2009). At the desalination plant, sea water first goes through a pre-treatment process which removes suspended particles before reverse osmosis process as mentioned under the NEWater process. The purified water produced is then remineralised like the previous process. Desalinated water is mixed with the usual treated water before supplying to homes and industrial estates. Singapore’s desalination plants meets about 10% of Singapore’s water needs and by 2060 the desalinated water is expected to meet 30% of Singapore’s demand.

4 Runoff from Local Catchments Singapore currently captures two-thirds (Figure of the rainwater that falls on Singapore’s land area. These runoff from the buildings, parks, canals are stored in the seventeen reservoirs (Figure 5) throughout the island. By continuously dating estuaries and capturing water from nearby streams, Singapore’s water catchment area can increase to 90% by 2060. The recent addition to our reservoir storage capacity is Marina Barrage, collecting the stormwater runoff from 10000ha area. The Marina Reservoir is separated from the sea with a 350m wide dam, mainly receiving freshwater from various canals. In addition, the barrage enables flood control for local flood prone areas. The reservoirs receive freshwater from 8000km network of drains and canals. 19

Figure 15 Singapore 17 Resevoirs (from https://www.pub.gov.sg/).

WATERWAYS OF SINGAPORE The rapid urbanization after gaining independence and frequent monsoon storms have threatened Singapore’s development with flash floods. In the 1970s, 3170 ha of land in Singapore were considered to be flood-prone areas (PUB, 2011). In December 1969, record showed 30 centimeters of rain in 24 hours, causing many parts of Singapore to be flooded with nearly 2 meters of water. This Great Flood of Singapore caused 3000 people to be left homeless and five people killed. Another huge flood occurred in 1978, causing 7 people to die and more than 1000 residents to be evacuated. Due to the high economic cost associated and great inconvenience created by flash floods, the drainage canal planning became one of the priorities of Singapore’s public utilities.

However, Singapore’s drainage planning began as a deterence to diseases. During the early 20th century, malaria was prevalent in Singapore because there were a lot of stagnant waters collected across the city, contributing to a conducive breeding ground for the Anopheles mosquito, a vector of malaria. Hence an anti malarial drainage system was concieved to prevent stagnant waters in 1914. The drainage system then consisted of naturally formed earth streams, subsoil pipes, and concrete drains (PUB, 2011). In 1932, a government report titled “Surface Water and Subsoil Water Drainage in Singapore” acknowledged the severity and importance of draining excess rainwater. Thus spark the start of proper drainage planning, the Singapore Improvement Trust

conceptualised a drainage plan with three primary objectives: i) To alleviate flooding and the inconvenience of access water and soft, muddy shorelines ii) To carry off sullage water and septic tank effluent from parts of town that is not yet connect to sewerage system iii) To minimize the breeding of disease carrying mosquitoes and insects With more and more land being built into buildings, more drainage canals were hastily built and provided to discharge into larger ones in the most convenient manner, often neglecting proper drainage planning or capacity of receiving drain. The most flood prone areas were often developed with the cheapest building techniques. Drainage systems from the areas were widened, deepened, and concrete lined to deter flooding (PUB, 2011). However, floods still persisted in Singapore. Finally realising flood was still a constant threat in Singapore, the various government agencies worked together to design a comprehensive drainage master plan based on current and projected land use. Following which, thedrainage system would be designed together with development of new towns. The land besides canals would be reserved for future need of canal widening for some existing canals. Width was designed based on statistics on the estimated flow from surface runoff based on the size of catchment area and history of rainfall intensity, and types of land surface catchment.

Redefining Water and Land

1950s Current Future Figure 17 Singapore Land Reclaimation

Over the years, to meet Singapore’s changing needs and support the ever increasing population, Singapore’s land area has increased 22% since its independence and will increase more in the near future. Most of such reclaimation happens around the edges of the main island, or expanded from the neighbouring islands. Semakau is one of the islands dedicated towards collecting incinerated wastes. As shown on Figure 7, due to the land reclaimation, the edges of the islands are redefined, either covering up the original outlets of the waterways or extending them further outwards, forming a clear division between land and water. In the reclaimation process, Telok Ayer Basin was removed, and the mouth of Singapore River flows into the bay rather than directly out towards the sea. This allows for whatever catchment that falling into 24

the river to be collected rather than released into the sea. The Marina Barrage was completed in 2008 to make Marina Bay into a reservoir in an attempt to increase catchment. The marina bay added 20% or135km2 worth of catchment area. There are plans to further add another 99km2 in the future. The Lorong Halus Wetland which was previously a rubbish dump, was transformed into 2 reservoir and water cleaning sites by damming the outlet of Sungei Serangoon. The city’s evolving relationship with our water resources could be observed in Figure 8, where the kallang waterfront near the Stadium and the old airport becomes more defined and streamlined over the years. Integrating the waterfront development into the urban fabric of the surrounding context contributed greatly to Singapore’s ecologically resposible reorganization of its water systems.

2016

1978

1954

1913

Figure 18 Land & Water Transformation at Kallang Waterfront

1 2 3 4 5 6 7 8 9 10 11 12 26

Kallang Canal Sungei Serangoon Sungei Bedok Stamford Canal Pelton Canal Sungei Seletar Simpang Kiri Singapore River Sungei China Sungei Ulu Pandan Sungei Ketapang Sungei Api Api Rochor Canal

10km 8.0km 6.7km 4.7km 4.3km 3.3km 3.0km 2.2km 2.2km 1.8km 1.6km 1.4km

Figure 19 Singapore Major Canals

13 14 15 16 17 18 19 20 21 22 23 24

Sungei Sembawang Sungei Tampines Sungei Pandan Sungei Whompor Sungei Lanchar Sungei Pinang Geylang River Alexandra Canal Siglap Canal Sungei Punggol Rochor River Sungei Simpang Kanan

1.4km 1.4km 1.3km 1.3km 1.3km 1.3km 1.2km 1.2km 1.0km 0.9km 0.8km 0.4km Total: 63km of waterways 27

Figure 20 Typical Sections of Canals

Figure 21 Examples of Canal Segments in Singapore

PARADIGM SHIFTS In the past decade, the public’s perception of the hardened canals aggregated. With increase knowledge and globalisation, humans are more aware of the relationship between environmental processes and their lifestyles. This led to the PUB in becoming more interested and invested in the shifting paradigms. Sustainability and “naturalization” became alternatives to concretised canals. The following reasons contributes to the reasons for Singapore in driving the next steps in water management.

1800s

1960s

1980s

Now

Future Figure 22 Children playing along the Canals (From: National Archives)

Figure 23 Canal Development in Section

â&#x20AC;&#x153;In the past, we pro keeping people away fr people clo

otected our water resources by rom them. Now, we will bring oser to water so that they will enjoy and cherish it more,â&#x20AC;? -Prime Minister Lee Hsien Loong 2007

PASIG RIVER MANILA

Attract: River Cleanup by reducing sewage and waste disposal Engage: Introduce cheap sewage disposal solution to the villagers, unite them in commiting towards a common goal of a clean river. Educate: Inform villagers of proper waste management.

Due to rapid urbanization along the riverbanks, and weak sewage infrastructures and no enforcements against industrial dumping, pollution from residential and industrial waste began to choke the Pasig River. By 1990, the river was filled with algal blooms, and only supports the hardiest biodiversity. The clean up first reduced waste from flowing into these open streams. The disposed wastes and garbage often obstructs and blocks water flow and result in

flooding

during heavy rain. These floods brings the polluted waters back to the villagers homes. With proper education of reducing waste disposal, the quality and conditions of the river became better. Through understanding and offering solutions, new innovations for clearing sewage was introduced to the villagers.

SUNGEI KLANG KUALAR LUMPUR

Attract: River cleanup and beautification schemes. Engage: Nil Educate: Nil

River of Life (ROL) project aims to clean Sungai Klang in its upper reaches and where it passes through Kuala Lumpur. Once the river runs clear, schemes to beautify the area and commercial development will flourish along the 10.7km stretch of the river in the city centre. Currently, the river remains as murky as ever. Many so-called clean-ups focused more on river beautification rather than the most important target of improving water quality. The main contaminants arre: wastes from sewerage treatment plants; commercial and residential centres; industries and workshops; and others. To improve the cityâ&#x20AC;&#x2122;s drainage and stormwater management system, river banks are being shored up to prevent erosion, which clouds up waterways. To maintain a natural riverine habitat, the city is moving away from concrete linings of river banks. 37

KALLANG RIVER SINGAPORE

Attract: Naturalisation of concrete canal into bioengineered constructed floodplains integrated with neighbouring park Engage: Offers various methods of engagement with water including water gardens and water playgrounds. Offers accessibility to the river stream. Educate: Information panels at stormwater management areas (Raingardens and Bioswales)

Originally a concrete canal, a 2.7km stretch of the Kallang River was restored into a naturalized river with bio-engineered river edges using a variety of plants and bedding. The naturalised river increased the accessibility of the river to the public, allowing them to appreciate the clean waters that was purified using pythoremediative measures. The river is designed using a floodplain concept, where the flow during the dry season converges into a narrow stream in the middle of the river. When a storm event occurs, the vegetated areas next to the stream will contain the excess water. This increases the canalâ&#x20AC;&#x2122;s original capacity. A water playground was also built to allow children to enjoy the water and learn to appreciate its qualities and value.

CHEONGGYECHEON RIVER SEOUL

Attract: Highway removed to reveal the underground stormwater canal that was turned into an urban green channel. Engage: Various gathering and activities along the channel. Offers accessibility to interact directly with the water. Educate: Nil

An elevated highway covering Seoulâ&#x20AC;&#x2122;s Cheonggyecheon River was taken apart to improve the areaâ&#x20AC;&#x2122;s environmental and aesthetic condition. The once polluted river made way and formed an arterial road in 1961. Due to structural failure of the highway that was bult in 1971, the government decided to revert back the river and restore it in three sections, differentiated by urban, urban-natural, and natural landscaping to respond to the different urban environments. The project also brought back biodiversity and interactive activities such as cycling, walking, Cultural activities are also promoted. However, it is often argued about its true success as the River itself is a fake portrayal of natural water flow. To keep a consistent flow of water for aesthetics, water has to be pumped up from a nearby lake. 39

COMPARISION From the 4 examples of waterway improvements in the region, we can observe a trend: Due to urbanisation, waterways become more and more dirty. In order to provide for a desirable water space, water needs to be clean in order to first achieve the goal of attracting visitors to the area. For the case of Pasig River it is clearing and cleaning of disposed wastes, while for the case of Kallang river is to clean up urban pollutants washed into the waterway. The engineered floodplains are designed to integrate with the use of raingardens and bioswales for treatment of the urban stormwater runoffs to clean up the contaminents. From the book River. Design. Spaces, it is recorded that there are 3 main types of urban pollutants that enters the waterway - Petroleum hydrocarbons, heavy metals and plant macronutrients (Figure 23). We can also observe that the 2 more successful examples: Kallang river and cheonggecheon river both engages the visitors directly with the waterway by means of meaningful activities. This is crucial in planning for introducing programmes into the underutilised concrete canal. Finally, in ensuring sustainability of the waterway, visitors have to be educated to understand how they can contribute to making the space better or how not to damage the area (Like Pasig River). Educating people on how water is automatically cleansed by plants is also useful in Singapore to further convince them that the water from the canal has been purified and safe to interact and play. In summary, in order to attract people to gather around water spaces, a clean environment is the key. The next factor is to foster direct engagement. with water and the last is to educate them about the waterway to create bonding and connection with the space and the waterbody.

Atmospheric Deposition

Pollutants from Urban Run Off

Pollutant

Typical Sources

Petroleum Hydrocarbons: Oil, Gasoline, Benzene, Toluene, PAHs, gas additive: MTBE: Methyl Tertiary Butyl Ether

Fuel spills, leaky underground or above-ground storage tanks

Metals: Boron (B), Cobalt (Co), Copper (Cu), Chromium (Cr), Iron (Fe), Manganese (Mn), Molybdenum (Mo), Lead (Pb), Fluorine (F) Lead (Pb), Mercury (Hg), Aluminum (Al)

Mining, industry, emissions, automobiles, agriculture, and lead paint

Plant Macronutrients: Nitrogen and Phosphorus

Agriculture and landscape practices

Figure 24 List of pollutants affecting urban waterways

CLEANING STRATEGIES How can we create a good environment with clean water? Currently in the market there are a few methods to do so. The first is preventive barriers to prevent people from litering or polluting the canal. This has been implemented all around Singaporeâ&#x20AC;&#x2122;s Canals. However, this does not prevent the contaminents that enters into the canal by other means listed in the chart the previous page. Next is using mechanical robots that floats on water, collecting trash that are deposited on the surface. This robot can also detect pollutants and water composition. It is solar powered and hence low maintenance. However, it is more applicable to rivers and canals with high water level. As Singapore canals often only have a base flow level, it is hard for such floating mechanisms to be efficient. Not only so, it is unable to clean up the sediments and finer molecules of contaminents. The commercial market also offers mechanical aeration. This is mechanically adding a pump system that provides oxygen and creates a internal water current to promote biodiversity. With more biodiversity thriving, pollutants and contaminents can be degraded by various means. Another way of aeration is a physical infrastructure. Weirs are often found to aerate rivers canals. It also enables sedimentation before the weir as it controls and redirect water flow. Thus enabling the water downstream to be cleaner and less sedimented or murky. Lastly is the method this thesis focuses on, which is natural remedies. The Bishan Ang Mo Kio park where the kallang river is naturalised uses techniques called phytoremediation, which is a part of the ABC programme supported by the government in creating enjoyable waters. This will be covered in the next pages.

PREVENTIVE BARRIERS

MECHANICAL AERATION

FLOATING ROBOT CLEANER

INFRASTRUCTURAL AERATION

ABC WATERS PROGRAMME The Active, Beautiful, Clean Waters (ABC Waters) Programme was hence initiated by PUB in 2006, to ensure a sustainable future for Singapore by radically transforming Singaporeâ&#x20AC;&#x2122;s network of drains, canals and reservoirs beyond their traditional functions of drainage, flood control and water storage into beautiful and clean streams, rivers and lakes. This forms a seamless network which is well integrated with the adjacent land developments, continuously creating new community spaces and encouraging new lifestyle activities to flourish in and around the waters. ABC Waters incorporates engineering, science, landscape design, the behavioral framework of urban design, and a commitment to community involvement. TheABC Water projects offer recreation spots that are accessible and free, enhancing the quality of life in an otherwise urbanised, fast-paced society. In fact, innovative ABC Waters design features (environmentally sustainable green features) are also being progressively integrated within the urban environment to detain and treat run-off before it reaches the waterways.

Active *Provide new community space *Bring people closer to waters *Develop a sense of ownership of Singaporeâ&#x20AC;&#x2122;s waters, through public education Beautiful *Integrating reservoirs and waterways with the urban landscape *Creating aesthetically pleasing lifestyle attractions Clean *Improving water quality *The project has a long term focus, and aims to implement more than 100 projects over 10 to 15 years.

In a recent paper published in the Journal of water management modeling, a survey of 50 randomly selected users of Bishan Park (walking, exercising or relaxing) within the area of the naturalized Kallang River was conducted. 60% of the survey participants were unaware of the implementation of ABC Waters Program in Bishan Park despite all the educational boards placed all around the park. 66% of the participants felt they did not have a good understanding about stormwater management 36% of the participants disagreed with the statement â&#x20AC;&#x153;Animal waste and soapy water from car washing are pollutantsâ&#x20AC;?, while an additional 4% were unsure about the statement. Similar percentages also disagreed that runoff from yards, parking lots and streets could be a source of pollution. This showed that while this is a successful naturalisation project, it did not really empower the users to understand more about the schemes and ideas behind the implementation.

Linear spatial expansion

Selective spatial expansion

Temporary resistance

Placing over the water

Tolerating

Adapting

ARCHITECTURAL STRATEGIES CANAL BANKS

Intermediate levels

Terraces

Broad riverbank steps

Parallel access to river

Perpendicular access to river

Closable Access

Temporary retainer

Balconies

Overhang

Suspended pathways

Submerged Planting

Submerged pathways

Underwater steps

Floating jetties

Floating islands

Moored ships

Extending the space

Placing over the water

Tolerating

Adapting

ARCHITECTURAL STRATEGIES CANAL BODY

Horizontal expansion

Floodplain reprofiling

Mounds

Buildings on piles

Flood resistant pathways

Sports and Playground

Floating and amphibous houses

Marinas

Retention Basins

Flood resisting parks

Application of the strategies in Singapore ALEXANDRA CANAL

Balconies

Suspended Pathway

Broadwalk

Application of the strategies Berlin, Germany SPREE BATHING SHIP

Moored Ship

Application of the strategies Lyon, France RHÃ&#x201D;NE RIVER

Terraces

Playground

Submerged pathways

REFLECTIONS The preliminary literary studies showed the progress in water management Singapore undertook in its quest for nation building. Of the many challenges and opportunities that drove Singapore to its current position in water systems, it looks to further improvements in providing a sustainable source of clean water through its 4 National Taps. This includes changes to its local catchment of a series of drains, canals and reservoirs. Being more ecologically responsible, there is a shift in the utilitarian position in terms of waterway treatment and we can see a shift back towards the naturalisation of the concretised canals. What does this actually mean for Singaporeâ&#x20AC;&#x2122;s future waterway developments? Will all waterways have multifunctional recreational centered uses ? Looking at the 4 cases of river rejuvenation, we found out that in order to create a successful water space, we need to attract, engage and educate the visitors. This can also be integrated with the various architectural strategies we can undertake in changing the water spaces into something more usable. As we reviewed the success of the Kallang river naturalisation, while it is successful in attracting and engaging, it is lacking in the educating factor. Being a pure landscape project, I wondered how architecture could supplement it in terms of education and in terms of attracting and engaging. Could Architecture be integrated with nature, to achieve the goal of educating users on water conservation whilst bringing human closer to water itself?

From the previous chapter, we observed that successful water spaces are clean and surrounded by greenery to maximise visitorâ&#x20AC;&#x2122;s enjoyment. As seen in the case of Kallang River in Singapore, we can utilise on natural remedies to help us achieve a sustainable and clean area of the canal. This chapter expands and explores how plants can help us to clean water.

PHYTOREMEDIATION

tldr; a process that uses plants to remove, transfer, stabilize, and destroy contaminants in soil and water

This mechanism is the process in which a contaminant is taken up by the plant and broken down into smaller parts (Figure 20). In most cases the smaller parts, called metabolites, are non-toxic. Th e plant often uses the byproduct metabolites in its growth process, so little contamination remains. The degradation occurs during photosynthesis or by internal enzymes and/ or microorganisms living within the plant.

Figure 19 Summary of Phytoremediation Mechanism

Figure 20 Phytodegradation: Plant Destroys Contaminant

1 Phytodegradation tldr; Plant destroys contaminant.

Figure 21 Phytovolatilization: Plant Extracts and then Releases Contaminant as a Gas

2 Phytovolatilization tldr; Plant releases it as a gas.

Contaminants can exist in several forms, for example as a solid, liquid and a gas. In this mechanism, the plant takes up the pollutant in either form and transpires it to the atmosphere as a gas, thus removing it from the site (Figure 21). The gas is usually released slowly enough that the surrounding air quality is not significantly impacted. The net benefit of removing the contaminant from the ground is typically better than any effect of releasing the pollutant into the atmosphere.

Figure 22 Rhizodegradation â&#x20AC;&#x201C; Soil Microbes Destroy Contaminant

3 Rhizodegradation

tldr; Microbes in the soil destroy contaminents.

The root exudates released by the plant and/or the soil microbiology around the roots break down the contaminant (Figure 22) while the plant provides for the phytochemicals and sugars that create a good environment for the microbes to thrive. The plant acts as a reactor for the contaminant to be broken down by helping to increase numbers of microorganisms and sometimes encouraging the growth of specific degrading communities of microbes (White and Newman, 2011).

Figure 23 Phytometabolism: Plant Incorporates Nutrient Contaminants into Growing New Biomass

4 Phytometabolism

tldr; Plant uses it in growth, incorporates it into biomass.

For plants to grow, they need nutrients as building blocks for photosynthesis and biomass creation. Phytometabolism is the process in which the nutrients needed by plants (inorganic elements such as N, P, K) are processed and turned into plant parts (Figure 23). In addition, once organic contaminants have been broken down by a plant (phytodegradation ), the metabolites that are left over from the process are often phytometabolized and incorporated into the plantâ&#x20AC;&#x2122;s biomass.

Figure 24 Phytoextraction: Plant Extracts and Stores Contaminants into Harvested Tissue for Removal

5 Phytoextraction

tldr; Plant extracts it, and for inorganics it is stored and must be harvested for removal.

Phytoextraction is the ability of the plant to take up a pollutant from soils and water and move it into plant parts (Figure 2.10). For Organic contaminants, they are easily removed from the site using phytoextraction and phytodegration methods. However, for inorganic contaminants, they cannot be degraded and broken down into smaller parts. Instead, the plant stores away the extracted inorganic pollutant in the shoots and leaves. For the pollutant to be removed from the site, the plant must be harvested before the leaves drop or the plant dies back. This method however, is seen to be less applicable to the Singapore context as it is very rare for singapore to harvest planting.

Figure 25 Phytohydraulics: Plants Change Groundwater Hydrology, Take up Water and Contaminants

6 Phytohydraulics

tldr; Plant pulls up water, and the contaminant may come with it.

Plants need water, and the pull created as water is brought into the roots is referred to as phytohydraulics (Figure 2.11). The pull can be so great that water can be drawn towards a plant, and masses of plants can actually reduce the flow of groundwater. Plants with this mechanism usually works together with other mechanisms such as phytodegradation or phytovolatilization, to eliminate the pollutant.

7 Rhizofiltration

tldr; Roots and soil fi lter water.

In constructed wetlands and stormwater filters, the roots of plants filter out pollutants from the water. The plants add oxygen and organic matter to the soil to maintain binding sites for contaminant filtration and storage.

Figure 26 Phytostabilization: Plant Holds Contaminants in Place and Prevents Mobilization

8 Phytostabilization tldr; Plant holds it in place.

The plant holds the contaminant in place so that it does not move off site (Figure 2.12). Th is occurs because vegetation is physically covering the contamination and the plant may also release phytochemicals into the soil that bind contaminants and make them less bioavailable. In addition, phytoaccumulation refers to the collection of airborne pollutants onto leaf surfaces, physically filtering contaminants out of the air and holding them in place. This mechanism is also less involved in the context as the primary concern is still removing contaminents from the canal water than the atmosphere itself. This could potentially be useful when considering roadside planting near the vehicular roads.

Figure 27 Summary of various phytoremediation mechanism

Particulate pollution carried in air

Particulate matter ďŹ lter for air

Degradation of organics occurring in plants and root zone

Volatilization of water and gases from soil and rain

Stabilization of inorganics in soil and water

Floating structure placed on surface of water to support growing plants

Water ďŹ ltered by plant root zone as current ďŹ&#x201A;ows by

Canal Flow

Organics may be degraded and inorganics trapped in root zones and growing media. Nitrogen in water may be returned to atmosphere as gas by bacteria

Pollutants mobilized in stormwater

Inorganics trapped in soil matrix and plant roots

Plants degrade organics from stormwater run-off

Nitrogen transformed to gas by bacteria

76 H

Colocasia esculenta (L.) Schott

Phragmites karka (Retz.) Trin.

Salix babylonica L.

Water Canna

0.2 - 1.5m

Thalia dealbata Fraser ex Roscoe

1.0 - 15m

Sea Hibiscus 黄槿

Talipariti tiliaceum (L.) Fryxell

Chinese Weeping Willow 垂柳

1.0 - 15m

Silver Fern 粉叶蕨

0.1 - 0.3m

0.5 - 1.5m

1.8 - 2.4m

Pityrogramma calomelanos (L.) Link

Pokeweed 土人参

Phytolacca acinosa Roxb.

Variegated Tropical Reed 卡开芦

0.6 - 1.0m

Lycopodiella cernua (L.) Pic.Serm.

Scrambling Clubmoss 筋骨草

0.4 - 2.0m

1.0 - 2.0m

Lepironia articulata

Rough Horsetail 木贼

Equisetum hyemale

Elephant's Ear

1.0 - 1.5m

Sweet Flag 水菖蒲

1.0 - 1.5m

0.2 - 0.5m

16 - 30m

Acorus calamus L.

Yellow Peanut Plant

Arachis pintoi

Brown Salwood 马占相思

Acacia mangium Willd.

NO3 - PO4 3-

Cu, Pb, Solids

C2H5OH, C6H6

NO3 - PO4 3-

Cu, Pb, Solids

Pb, Solids

Fe, Mn

Cu, Cr, Pb, Fe, Ni

Thalia dealbata Fraser ex Roscoe

Barringtonia acutangula (L.) Gaertn.

Crinum asiaticum 'Variegatum'

Fagraea ceilanica Thunb.

Water Hyssop

Bacopa caroliniana (Walter) B.L.

Fibre Optic Grass

Isolepis cernua (Vahl) Roem.

Chameleon Plant 鱼腥草

Houttuynia cordata

Paper Plant

Cyperus papyrus

Perfume Flower Tree 灰莉

Striped Bengal Lily

Red Barringtonia

0.1 - 0.3m

0.2 - 0.5m

0.2 - 0.3m

2.5 - 3.0m

1.0 - 5.0m

0.2 - 0.5m

5.0 - 15m

Creeping Fig 薜荔

0.1- 0.2m

1.0 - 5.0m

0.9- 1.5m

1.5 - 3.0m

0.2 - 1.5m

Ficus pumila Linn.

Cannonball Mangrove 木果楝

Xylocarpus granatum J. Koenig

Variegated Broad Leaf Cattail

Typha latifolia 'Variegata'

Narrow-leaf Cat Tail 狭叶香蒲

Typha angustifolia L.

Water Canna

1.0 - 15m

Sea Hibiscus 黄槿

Talipariti tiliaceum (L.) Fryxell

Petroleum

Cu, B, Fe, Mn, Zn

NO3 - PO4 3PAHs, NH4, Pb, Ni C21H20Cl2O3, Cu

Cu, Pb, Ni, Fe, Mn, Zn

NO3 - PO4 3-

C21H20Cl2O3

NO3 - PO4 3-

Cu, Pb, Solids

PENG SIANG RIVER

Public Resdiential Highrise/ Park Flow rate: 1.4m3/s Canal Width: 45m Depth: 3.5m Water content: Murky Water Pollution Level: Medium

BUKIT TIMAH CANAL

Private Residential/ Commercial/ Park Flow rate: 0.7m3/s Canal Width: 35m Depth: 5m Water content: Contaminated Water Pollution Level: Medium

BEDOK CANAL

Private Resdiential/ Industrial Flow rate: 1.0m3/s Canal width: 38m Depth: 3.5m Water content: Murky, Contaminated Water Pollution Level: High

BEDOK CANAL

BUKIT TIMAH CANAL

PENG SIANG RIVER

WA Y (P

IE)

FARRER ROA

ISL

PAN

BUKIT TIM

AH CANA

BUK

IT TIM

SINGAPORE BOTANICAL GARDENS

AH R

OAD

Chosen Site Bukit Timah Canal

Of the 3 sites located, Bukit Timah is located centrally in Singapore and features a wide range of visitors (Students, Tourists, Residents, Locals). If we open up the canal at this location, there are many potential visitors who can benefit from accessing the canal and hence foster better interaction with water. In addition, when we compare the site locations with the rain pattern map, we can see this location has a patternt that relates back to most of Singapore. The canal on site is very inaccessible, but it is not hidden away from the bridges, by implementing a design in this area will bring about better walkability and enjoyment to passerbys.

Figure Ground Bukit Timah Canal

Based on the figure ground profile, we can see it is a very urban site with dense building footprints.

Pedestrain Flow Bukit Timah Canal

This shows the amount of people around the site. We can see that most people gather around the roads and bridges. Most of the visitors are found near the sixth avenue MRT station and the connecting bridge.

RESIDENTIAL RELIGIOUS EDUCATIONAL COMMERCIAL

Programmes Bukit Timah Canal

RECREATIONAL

Most of the programmes are private residential housing with some commercial and recreational buildings close to the canal. The canal can be a connection for these commercial places, helping them connect to other areas. While the commercial places can also bring visitors to the site.

Vehicular Paths Bukit Timah Canal

The canal is surrounded by 2 major roads Bukit Timah Road and Dunearn Road. This poses potential issues to the accessibility.

Water Flow Bukit Timah Canal

The water flow in this part of the canal is base level. It can rise to full during raining days and discharges within 12 hours. further downstream more water joins the canal forming a higher water level.

88 RO AD

OVERHEAD WALKWAY

FARRER ROA

FOOD MARKET

ENCLOSED CANAL

COMMERCIAL BUILDINGS

THICK VEGETATION

WIDE CANAL 32M

SEDIMENTS BUKIT T

IMAH C

BUK

IT TI

SIDE DRAIN

PLANT CENTRE

SINGAPORE BOTANICAL GARDENS

ANAL

MAH

ROA

ENVIRONMENTAL LEARNING FACILITIES As Bukit Timah site was chosen, it was also apt for the programme to match the site. Since Bukit Timah is located centrally amongst educational institutions and next to the botanical gardens, it makes sense to introduce a learning facility to educate people more about both canals and plants. Here we analyse different types of educational facilities to better understand the programmes, facilities, site context and environmental strategies that the various institutions uses in order to apply to the chosen site. To determine the scale for this project, projects of different scales are chosen to make a comparative analysis. In addition, these projects are also selected based on their integration with water. These projects are: Brockholes Nature Reserve Visitor Centre; Karura Forest Environmental Education Centre; Burle Marx Education Center; Kansas Wetland Education Center. The cases are dissected to give a more holistic analysis on the various contributing elements that makes up an educational facility. These various elements are then pieced together to form a more cohesive judgement. There are a total of 7 elements, inclusive of 1 element that relates to the interaction of the architecture to water.

1 Project Scale As with any architecture, the project scale affects any form of architecture. Getting the right scale will ensure the usability and sustainability of the architecture. No one educational facility is

the same size or scale as another. Understanding the project scale is a beginning understanding the project 2 Project Context Many of the facilities are situated right next to the evironment that they seek to educate. As such, understanding the site context and building foot print in relation to the contextual information is important in understanding the rational behind choosing the location and size. 3 Programme Types To understand what programmes are required for the water learning center, we need to analyse what each of the case studies features and evaluate if it is applicable in the context of the thesis. These programme types if overlapped, could indicate to us the importance of including them in the design brief. 4 Programme Scale Likewise, we will need to anayse the scale of each programmatic space so as to understand how the different programmes could work together in achieving the eventual product of an educational facility while not standing out and forming an entity or attraction on its own. 5 Programme Relationship Here highlights how each programmes intuitively interacts with each other in the cases. do they merge and complement each other or are they simply segregated in their functions? These information will assist the future planning on how to position these different programs together.

6 Sustainability Approaches Educational facilities are often equipped with energy saving options to reduce the operational energy consumption in order to be sustainable. It is also somewhat justified that it can be a testing ground for the energy saving concepts and serve as a environmental education outlet in installing sustainable energy options like solar panels, and green roofs. The main idea is self-sufficiency by harnessing energy from nearby and achieving the result of not harming the environment.

7 Interaction with Water As the thesis focuses on rebuilding the relationship between human and the appreciation of water through understanding the canals, it is interesting to see and evaluate how the various educational facilities come together with water to inculcate knowledge of water and promote the appreciation of water. these 3 cases all have different approaches in how they sit on water or curates the experience with water.

Project Scale & Project Context

BROCKHOLES VISITOR CENTRE

KARURA FOREST ENVIRONMENTAL EDUCATION CENTRE

Adam Khan Architects 2011

Boogertman + Partners Architects 2016

Built-up Area: 2795 m2 Brockholes is a new nature reserve, constructed using remains of an abandoned quarry in Preston, England. The area has been rehabilitated with wetlands, a hay meadow, woods and hiking trails to take it all in. The visitor centre floats in the middle of the wetlands and serve the public who comes to appreciate and learn about the environment.

Built-up Area: 2100 m2 This center is located in the northern part of Nairobi County, Kenya. It seeks to educate people on the biodiversity within Karuraâ&#x20AC;&#x2122;s diverse landscape and aim to sensitize and educate people on current and emerging national and global environmental issues.

EDUCATION CENTRE BURLE MARX

KANSAS WETLANDS EDUCATION CENTER

Built-up Area: 1704 m2 The building was built next to the main entrance of Inhotim Institute, USA as a tribute to the famous Landscape Architect Roberto Burle Marx. It is near the reception and one of the existing ponds. The horizontal building, just one level above the lake attempts to mimic the building in the existing landscape.

Built-up Area: 1000 m2 The crescent shaped visitor center located in Kansas, USA geometrically surrounds the marsh, offering great wildlife views from all the interior spaces. The center exhibits the story of the inland marsh, from its geological formation to the environmental challenges of the future. The education center extends its viewing platform to the centre of the marsh.

Alexandre Brasil + Paula Zasnicoff 2009

BBN Architects 2009

Programme Types, Programme Scale, Programme Relationship

146.5m2

566.8m2

242.3m2

60.6m2

212.3m2

456.8m2

64.9m

67.6m2

307.5m2

95.1m2

108.3m2

54.1m2

41.0m

44.2m2

65.6m

76.7m2

2 2

95.6m2

62.2m2

1308.6m

608.8m2

BROCKHOLES VISITOR CENTRE

KARURA FOREST ENVIRONMENTAL EDUCATION CENTRE

Adam Khan Architects 2011

Boogertman + Partners Architects 2016

The visitor center seeks to be a carbon neutral event venue, featuring 100 pax auditorium and 100 pax cafeteria and exhibition and information spaces. Half of the floating platoon houses programmatic spaces while the rest are fully circulatory spaces. These free space also serves as a viewing platform for the visitors to appreciate nature and features trees for visitors to take respite in.

The programmatic spaces include a bird watching hideout, a flooded room in the forest for meditation, an amphitheatre, viewing decks from the tower, event spaces and access to forest walks, with a indoor Auditorium for 200 pax, a 25 pax cafeteria and a e-library. Alongside the building, landscaping include an outdoor amphitheatre that is surrounded by nature and fresh air of the forest.

270.2m2

78.6m2 29.8m2

147.3m

70.0m2

305.6m2

195.9m2

58.1m

54.1m2

45.7m2 108.8m2 32.4m2

81.7m2

30.6m

49.6m2

47.5m

49.4m2

2 2

25.2m2

42.0m2

1107.2m

373.5m2

EDUCATION CENTRE BURLE MARX

KANSAS WETLANDS EDUCATION CENTER

The main entrance to the building is through a sunken square that turns into a broad amphitheater leading the public to a reception area. From the reception area, one can access directly the library, the studios, the 200 pax auditorium, and the 50 pax cafeteria. Most of the educational facilities like library and classrooms are spanned above the water, providing view out to the landscape.

Unlike the other 3 cases, this education center does not feature a cafeteria, but a giftshop and a research lab for working biologist to research on the native biodiversity of the inland marsh. Whilst being mostly educational and informative, it also has a small amphitheatre of 50 pax and classroom for another 50 pax. Besides being the smallest center, it features a open reception that leads directly to the viewing point.

Alexandre Brasil + Paula Zasnicoff 2009

BBN Architects 2009

Sustainability Approaches, Interaction with Water

Natural Ventilation

Recyclable Materials

Natural Materials

Natural Water Treatment

BROCKHOLES VISITOR CENTRE

Natural Ventilation

Water Catchment

Natural Materials

Environmental Conservation

KARURA FOREST ENVIRONMENTAL EDUCATION CENTRE

Adam Khan Architects 2011

Boogertman + Partners Architects 2016

The pitched roofs of the various spaces are good for air circulation and extraction. Natural sustainable materials are used for the construction of the building.

Over the water, the natural timber screens use light and passive cooling systems to create comfortable cohabitation space by blocking the west sun and allowing natural ventilation.

The floating nature of the building offers an intimacy with the water that it would lack if it were ringed with defences against flooding: the water is turned from an enemy into an ally. 98

The water catchment area not only reconnects nature with visitors but also acts as a cooling element for the building.

Natural Ventilation

Natural Water Treatment

Environmental Conservation

Natural Materials

Recyclable Materials

EDUCATION CENTRE BURLE MARX

KANSAS WETLANDS EDUCATION CENTER

The building reinforces the relationship between architecture and landscape, floating over the lake, creating a beautiful garden on its roof, promoting open air circulation spaces, and it also integrates art and nature.

The center has a floating bridge spanning across the marsh land to the view point, which each internal areas overlooking into the water. The building itself comprises of natural materials sourced from the nearby marshlands.

Alexandre Brasil + Paula Zasnicoff 2009

Using the natural cooling nature of water, and recyclable building materials, it provides comfortable natural ventilation.

BBN Architects 2009

CASE STUDY ANALYSIS & APPLICABILITY TO CONTEXT 1 Project Scale From the four examples we can observe that, although all are educational centers, the size of the facility could range from 1000 m2 to 3000 m2. The scale is directly and indirectly related to the site it sits on. As most of the facility sits on the nature site, the activities offered on site determines the facility scale. The popularity of the nature site or facility. Hence it is understandable that since the Kansas Marshlands are smaller in size as compared to the Karura Forest area, the size of the center is also smaller. ctiv 2 Project Context The project context of the cases are mostly nature sites. All 4 were chosen to be close to water bodies. In particular, for Brockholes nature reserve and Karura Forest, the facilities are located within a giant compound of natural habitat as compared to the other 2 cases. This could have also impacted on the scale of the facility as it is possibly the few location in the neighbourhood that provides amenities for the visitors. 3 Programme Types According to the chart, they all have similar types of educational programmatic spaces like exhibition hall, library, classrooms, amphitheatre. The main difference is the amenities provisions like Cafeteria, giftshop, toilets, storage, and offices.

100

4 Programme Scale From the different cases, we can see that a huge percentage of total area is given to circulatory spaces. This is ap-

parent in the case of Brockholes Visitor Center where almost half of the space on the floating platoon is attributed to circulation. The circulatory spaces in the various cases not only serves to bring people from programme to programme but also to bring people closer to the natural environment, hence justifying the overwhelming attribution. In fact, one can see that useful circulatory spaces are the most important programme for environmental education centers as nothing is better in educating than the real thing itself. 5 Programme Relationship Most of the programmes are well interspaced. Exhibition areas are seen to have the center stage, with other facilities located around it. Offices and other services are tucked away. For the Burle Marx educational center and the Kansas Wetland education center, the indoor auditoriums are seen to be located nearer to the reception. However, in all 4 cases, the auditorium are positioned away from the normal traffic flow, tucked away to a less visited area. 6 Sustainability Approaches It is surprising that these few cases are not equipped with renewable energy facilities. Instead, their approaches are all to reduce the need for energy consumption, and reduce the carbon footprint of the building itself. Most of the cases uses materials sourced naturally near the site itself. This may seem like a small step but it contributes significantly in notintroducing more things into the intervention. Also by doing so, it reduces the carbon footprint caused by transportation of the materials.

7 Interaction with Water As seen in both the plans and sections, all of the centers are surrounded with water bodies. The Brockholes visitor center is fully surrounded by water, while the rest are partially sitted on the waterbodies. For Karura Education Center and Burle Marx Education Center, they used stilts to support themselves as it overhangs onto the water surface. Both Karura Educational Center and the Kansas Wetlands Educational Center has a central observation tower that allows unrestricted views into the waterbody. The brockholes visitor center however, floats and respond to the different water levels hence allowing visitors to have a closer and more intimate relationship with the waterbody. Through the 4 examples we have discovered 3 different methods of building above water that allows architecture to engage with the water body. They are namely, floating, elevated, and hybrid of dike and elevated. As illustrated in Chapter 2, there are many architectural strategies we can apply to our project.

101

PROGRAMMATIC CONSIDERATIONS Based on the case studies, the various size and scale of programmes are measured and adapted into my design. Project Aim The thesis design aims to 1 bring visitors closer to water and waterways 2 educate the visitors interactively about phytoremediation 3 supplement Botanical Garden researchers with additional research planting area to study more about phytoremediation. Project Scale The project will be of an average scale of about 7500m2 upon studying the case studies and comparing with the context of Singapore. Singapore itself has a huge population and hence the center must be able to accomodate many visitors. In addition, the educational facility will feature a planting area for the researchers to study phytoremediative plants. Programme Types Based on the project aim, the education center will feature educational facilities like classrooms (40 pax), 1 amphitheatre of more than 200 pax, 1 research laboratory, 1 feature exhibition area featuring ABC projects undertaken by the government and a 1000m2 exhibition space for exhibiting phytoremediative plants complementing the surrounding landscaped area. Programme Scale The programmatic scale will be larger to that of the Karura Forest Education Center, with a cafeteria for 100pax, toilets with 5 cubicles each. These findings and decisions are documented in the form of a relationship bubble diagram which will be applied onto site.

102

LECTURE THEATRE 700m2

RETA 300

OFFICE 400m2

V C 1

PHYTOREMEDIATION STUDY AREA 800m2

TAIL 0m2

RESEARCH 400m2

VISITOR CENTER 1000m2

CLASS ROOM 300m2

LIBRARY 400m2

EXHIBITION 1200m2

CAFE 300m2

103

104

105

106

107

108 EXHIBTION HALL

EXHIBTION HALL

CAFE LIBRARY/RESOURCE CTR

RESEARCH LAB

STUDY ROOMS LIBRARY/RESOURCE CTR

RESEARCH LAB

WET NURSERY

CLASSROOM

TOILETS & SERVICES

ABC PROGRAMME CTR

VISITOR CENTRE

COVERED WALKWAY

GIFT SHOP

LECTURE THEATRE

OFFICE

ADAPTABLE BRIDGE ENTRANCE

RAIN GARDEN

FLOATING WETLAND

SUBMERGED WETLAND

GIFT SHOP

TOILETS & SERVICES

OFFICE

SUBMERGED WETLAND

RAIN GARDEN

FLOATING WETLAND

SHALLOW POOL

SECOND STOREY PLAN 0

10m

25m

50m

100m

2.0m 1.6m

1.0m 0.6m

WET NURSERY

SHALLOW POOL

0.1m

FIRST STOREY PLAN 0

10m

25m

50m

100m

109

Inspiration Braided Rivers

Braided Rivers are chosen as a replacement to the current baseflow geometry. This is in consideration of the fluidity of the geometry as well as for its practicality. Braided rivers is caused by the sedimentationof the various solids carried by the river. It helps to slow down the speed of the water and with more water exposed to the sedimentation grounds it helps to encourage growth of the plants. This is also a good opportunity for the plants to be in contact of the water flow in order to clean the water that comes in.

110

111

Design

phytoremediation

My concept was to create an education facility focusing on the research and education of phytoremediation technologies. This integrates seamlessly with the braided river inspiration as the islands that separates the braid can form into phytoremediative wetlands that weaves around the education center. The organic islands form by the braided rivers creates also the opportunity of increased area in cleaning the base flow water from the canal, resulting in cleaner water. There are 2 ongoing strategies that helped to shape the design. Phytoremediation Integration Phytoremediation techniques is used to develop the canal into a more pleasant environment. This is done by: 1 - Desired Volume of Canal Water. In order for my design to achieve itâ&#x20AC;&#x2122;s desired function, there needs to be more water in this section of the canal as from the site analysis, when there is no rain, water flows into the base flow channel while exposing the concrete surfaces. 2 - Water Purification. In order to bring people closer to water, the water flowing in the canal must be clean at normal conditions. This strategy anchors on plant technologies. Building Design Development As previously mentioned on the choice of an education facility, this facility is focused on phytoremediative techniques to integrate with the process and teach its applications. This is also in complement of a plant nursery research facility opposite the road in the botanical gardens. This is anchored on architectural strategies. In this document, we look at the architectural developments first. 112

113

BUKIT TI

MAH CAN

BUK

IT TIM

AH R

SINGAPORE BOTANICAL GARDENS

BUKIT TI

OAD

MAH CAN

BUK

IT TIM

AH R

SINGAPORE BOTANICAL GARDENS

BUKIT TI

OAD

MAH CAN

BUK

IT TIM

SINGAPORE BOTANICAL GARDENS

Site Access Planning Plan

Based on site analysis, the site is highly secluded and very inaccessible. To attract and engage visitors, more entrance points needs to be created. Based on the observed visitor intensity along the routes , 4 main points were identified and connected to form a visiting loop. 114

AH R

OAD

BUKIT TI

MAH CAN

BUK

IT TIM

AH R

SINGAPORE BOTANICAL GARDENS

BUKIT TI

OAD

MAH CAN

BUK

IT TIM

AH R

SINGAPORE BOTANICAL GARDENS

BUKIT TI

OAD

MAH CAN

BUK

IT TIM

SINGAPORE BOTANICAL GARDENS

AH R

OAD

115

BRANCHED COLOUMN STRUCTURE

SECONDARY CIRCULATION

STAGGERED PLATFORMS

(RESEARCH, LIBRARY, CAFE SPACES

RESEARCH PLANTING

PROGRAMME ARRANGEMEN

Building Design Development isometric

Based on the access points obtained from the site information and analysis, various connectivity routes were proposed and applied to the site geometry. Primary and secondary routes form the main access paths that surrounds the building with a series of ramps traversing up and down the floating island. Interior programmes are interconnected by the ground floor open circulation scheme. Floors were staggered to provide different levels of privacy, steps leading down from the circulation paths form a lecture theatre to make use of the level difference. 116

LIGHT WEIGHT ROOF

MAIN EXTERIOR CIRCULATION LECTURE THEATRE SEATING

NT GROUND FLOOR CIRCULATION

117

118

119

SECTION AA’ SCALE 1:200 0

10m

20m

10m

20m

SECTION BB’ SCALE 1:200 0

Building Design Development section

The design of the building follows the geometry of the simplified braided rivers, taking the form of a floating island. The island floats vertically in order to adapt to the changing water levels in the canals The interior of the body is sunken. When water levels reach above 1.5m, the water level will be at chest level, offering a new visual experience, bringing people closer to water.

CAST-STEEL NODE

ALUMINIUM CLAMPING STRIP 3 LAYER ETFE FLIM DIAMETER 400mm STEEL TUBE

121

ROOF PLAN SCALE 1:2000 0

20m

50m

100m

200m

SCHEMATIC RAINWATER FLOW DIAGRAM SCALE 1:2000 0

122

20m

50m

100m

200m

123

124

Building Design Development roof details

ETFE Roof is chosen for its lightweight durable structure that works well with the floating island. The structure is supported by branched coloumns shaped like a tree to create the mound like roof structure. As ETFE is transparent, to cut down on the amount of sunlighting and to reduce solar radiation, prints can be created at strategic locations as shown on the left to provide variated sunshading. In addition, 3 layers of ETFE is used as opposed to 2 layers to provide more insulation. The print pattern is designed to carry the geometry of the braided river arranged into a collage of leaves with various density. This is in reference to the elephant house in copenhagen zoo. The design can be further explored to look at variable shading options. One example is to have overlapping patterns for the different layers of ETFE. by adjusting the pnuematic pressure within the ETFE pillow, One can control the amount of overlapping and thus control amount of light that enters the surface.

125

Phytoremediation Integration techniques strategies and area determination

The floating education centre alone does not make up the whole project. In fact, it does not work as a standalone item. This is due to the constraints posed by the site. Phytoremediation is the technique I am employing to solve both the issues of water level and water cleanliness. 1 increase the volume of water at normal conditions in order to create a pleasant environment. We donâ&#x20AC;&#x2122;t want to be looking at concrete all around the architecture. To achieve the braided river geometry, we will need 620

3120

Base flow

Additional water

3740 Amount of water l/hr

3740 litres of water an hour base on a base flow of 0.7m3/s and a water level of 0.5m. There are 2 ways in approaching this scenario. Firstly is to pump clean water into the canal to provide the artificial impression of a decent water level, similar to that of the Cheonggyecheon River. Next approach is to utilise the unique rain pattern in Singapore. As mentioned in the climate of Singapore, Singapore rains 178 days a year, which means there are rain every 48-72 hours. This provided the opportunity to retain rainwater over a period of 48 hours and slowly discharge it over the 48 hrs at a consistent flow rate to achieve the desired canal water flow amount. After 48 hrs, the next rain event will replenish the tanks with a new supply of water to discharge for the next cycle.With this in mind, over 48 hrs, I would need 122080 litres of water. To supply that I decided to utilise phytoremediation based technology known as bioretention tanks and filters. Bioretention tanks are also known as Rain Gardens while the filters are known as Bioswales. Based on the calculations by the Rain Garden Alliance website, I would require 1800m3 of biorentention tanks and filters. Rain Gardens not only provides the volume of water I need, but also provides them cleansed by the works of Phytoremediative plants.

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2 water cleanliness. To achieve this, there are many methods - One is protective barrier which is what we already observe; the other options are mechanical cleaners like the robot vaccum, to actively clean our canals and also mechanical aeration technologies like wiers and pumps. The mechanical solutions does not help us since there will be periods where there are little water, hindering the functionality of the mechanical helpers. We must understand that the raingardens and bioswales works only on rainwater inputs so we cannot rely on them to fully clean our water. however, base flow water constantly passes through the canal and has to be cleansed as well in order to achieve a clean and beautiful canal. This can be achieved using constructed wetlands. In calculating the requirements for the amount of wetlands, I referenced the paper on Phytoremediation as Green Infrastructure and obtained a reference of 1 unit of wetland is to 0.045 of residential land unit. This allowed me to to calculate the need for approximately 8900m3 of wetlands. This is different from the calculations for wastewater treatment by constructed wetlands as canal water is flowing water as compared to the waste water treatment where the water stays for a prolonged period of time. Hence the figure is justifiable as compared to that of raingardens since more wetlands will be needed to clean the flowing water than cleaning stationary waters. To create a better environment, I have also introduced fragrant and aesthetical plantings together with the phytoremediation plants to not only provide clean waters but also clean air and fragrant environment to deter the negative connotations of concrete canals. Hence I have allocated 10000m3 of wetland areas. The quantities and amounts of various phytoremediative technologies are recorded in the diagram next page. The raingardens supply the water collected from each rain event to the canal to allow the canal channels to have a consistent water level. As such, they are positioned at the start of the canal site. Next the group of wetlands are positioned over the entire stretch as they not only clean the base flow but also the surface runoff as well as any contaminents brought in by the building activities. The wetlands are staggered to provide a varying visual experience.

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Bioswale

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Rain-garden 2000m2

Submerged wetlands 6000m2

Floating wetlands 4000m2

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PLANT PALATE

PLANTING ENVIRONMENT

BIOREMEDIATION STRATEGY

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Phytoremediation Integration constructed wetlands

In Section AAâ&#x20AC;&#x2122;, we can see that at the connecting corridor that provides a viewing platform towards the planted wetlands on both sides. When the water level rises and the architecture floats, one of the wetlands floats while the other submerges. This is implemented not just for aesthetics but also for cleaning efficiency. Some plants phytoremediate with their roots and some activate the soil for phytoremediation. By having both systems, we can clean different contaminents creating a better environment.

CONSTRUCTED WETLANDS SECTION SCALE 1:200 0

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10m

20m

PLANTING MEDIUM DRAINAGE LAYER HOLDING STRUCTURE

FLOATING TUBES EXPOSED ROOTS CONNECTING CHAIN

FLOATING WETLAND

FILTER MEDIA (SANDY LOAM) OVERFLOW PIPE DRAINAGE LAYER (WASHED FINE GRAVEL) WATERPROOFING CANAL FLOOR BED

BIOENGINEERED WETLAND

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FICUS PUMILIA PUMICE STONE COPING

SEDIMENT FOREBAY FILTER MEDIA (SANDY LOAM) TRANSITION LAYER (COARSE SAND) DRAINAGE LAYER (WASHED FINE GRAVEL) GEOTEXTILE WATERPROOFING

RAIN GARDEN (BIORETENTION BASIN)

100mm MULCH PERFORATED DRAINAGE PIPE

FILTER MEDIA (SANDY LOAM) GEOTEXTILE SUBGRADE SOIL

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BIOSWALE (BIOFILTRATION CHANNEL)

Phytoremediation Integration cascading rain gardens

As explained, rain garden is integral to this project not only as a cleaning mechanism in providing clean attractive waters but also as a water collector. During rain, it collects water by filling up the biorentention cells with special filter medium

Over a period of 48 hrs, it will slowly release the water in these cells via the weep holes connecting the cells and into the canal channel. The water released is purified through the use of plants with phytoremediative characteristics.

It is expected that with Singaporeâ&#x20AC;&#x2122;s rain pattern, rain will refill the cells with water after 48 hrs to keep the canal water level consistent. Despite so, even when there is no rain, water from the normal surface runoff can be cleansed too before flowing into the canal, keeping the canal water consistently clean

CASCADING RAIN GARDEN SECTION SCALE 1:200 0

10m

20m

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SCHEMATIC FLOW SYSTEM

STORMWATER BIOSWALE

SURFACE RUN-OFF

SANKEY FLOW DIAGRAM

BASE FLOW

After Design Implementation CONTENTS OF CANAL WATER

INFLOW SOURCE

STORMWATER WATER

PHYTORE SURFACE RUN-OFF SOLIDS

CONTAMINENTS

HEAVY METALS

BASE FLOW

MAJOR IONS

SANKEY FLOW DIAGRAM

Before Design Implementation CONTENTS OF CANAL WATER

INFLOW SOURCE

STORMWATER WATER

SURFACE RUN-OFF SOLIDS

CONTAMINENTS

HEAVY METALS MAJOR IONS

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BASE FLOW

EMEDIATION 1

Phytoremediation Integration water cleaning system

RAIN GARDEN

This diagram summarises the various actions by the phytoremediation strategies and the eventual output. We can see that not only is the water cleaner, but also there is more canal water at the end of the sankey diagram.

CONSTRUCTED WETLANDS

OUTPUT

OVER FLOW

CANAL WATER PHYTOREMEDIATION 2

PHYTOREMEDIATION 3

SEDIMENTS ABSORBED CONTAMINENTS

OUTPUT

OVER FLOW

CANAL WATER

CANAL WATER is defined as water in canal 24 hr after storm event.*

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