Designed Ecologies: celebrating natural systems in the city

DESIGNED DESIGNED ECOLOGIES ECOLOGIES celebrating natural systems in the city 911118 LILIE PAXTON-WHITE

2. early iterations 6. explorations and precedent

16. swale detail section

10. sections and

20. explorations in

perspective

14. site analysis and perspective

12. form development and watershed

10. little site master plan

24. sit

CONTENTS CONTENTS

18. big site analysis development

n voronoi

30. site axonometric and planting

28. site anaylsis - equal access, circulation, zoning

22. master plan

36. raingarden planting detail section

40. inlet detail section

60 mm

45 mm

30 mm

15 mm

42. perspective 2

38. perspective 1

26.planting and management

te sections

s and early

34. changing conditions on site 32. water volume calculations

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design exploration exploration 11 design Very early on in the design process for this site, I saw a pattern emerging in the form and functions of the various plans I produced. There was an emphasis on natural systems - in particular the movement of water, which is seen in the repeated form of the swale which cuts across the site diagonally for each of these exercises.

I also became interested in the juxtaposition of natural systems and geometric forms, which highlights the dichotomy of natural parklands in the highly managed urban environment.

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design exploration exploration 22 design

Above: detail of the raingarden at the Edinburgh Gardens, Fitzroy North. http://landezine. com/index.php/2012/10/edinburgh-gardensraingarden-by-ghd-pty-ltd/

I decided to explore this idea of the geometric, almost sculptural form of the swale as a way of highlighting and celebrating water movement. I remembered a precedent I had seen at the Edinburgh Gardens where the design of the raingarden becomes a feature of the landscape rather than simply a functional space, and I wanted to explore this idea in my design.

I was also drawn to the use of the raised corton steel channel which during rain events fills up to become a reflective water feature.

I appropriated this for an early iteration of my design (left), which shows how the channel is cut in to the base of the swale as a means of collecting water. To ensure infiltration however, the base is a course gravel that allows for drainage.

This detail would become a repeated theme throughout my iterative design process.

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ITERATION 1

As the site slopes down towards the south-east corner, one of the first landform movements I implemented was to raise this corner of the site to prevent water pooling at the base of the walls.

This also means that if the swale cuts across diagonally, water will flow down towards it from both sides.

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ITERATION 2

I then looked at other subtle land employ to further influence wate site into separate planes and tiltin swale, water sheets across the sit where infiltration can occur.

design exploration exploration 33 design 30.4

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dforming techniques I could er movement. By dividing the ng them all down towards the te and collects within the swale

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ITERATION 3

This iteration looks more closely at the design of the swale, and how it can be sliced into the existing landform to allow for collection of a greater volume of water, as well as creating interesting geometric forms which change the experience of the site.

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2 SECTION

SECTION 1

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THE THELITTLE LITTLESITE SITE KEY:

Eucalyptus stricta Blue Mountains mallee ash

high-albedo concrete biodiverse groundcover/ turf

0.1m contours steel channel

Master plan

This is the design I chose for the interim submission. It is very similar to the iterations I explored previously, however the contours have been refined to create an interesting geometric landscape that increases water movement into the swale.

Initially I wanted the site to be predominantly vegetated to help decrease UHI on site, however through the use of high albedo concrete this is still achieved to some extent, and water runoff is increased, meaning rain events result in a more dramatic accumulation of water on site.

During dry periods these concrete landforms can also be used by local skaters, who were displaced from Lincoln Square.

MASTER PLAN 1:250@A5

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SITE PERSPECTIVE 1

Showing context from the corner of Pelham and Leicester Sts - open space vs planted areas.

The landforming on site was utilized to influence water movement towards the swale. Water is captured from the footpath and flows onto site following the direction of the contours. The raised concrete forms along Leicester St direct water along the footpath towards the start of the swale to lengthen the path the water travels along, and thus increase infiltration.

Trees were located along the edges of the swale so they have ample access to water, and to provided shade in the most exposed part of the site.

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SECTION 1

SECTION 2

SECTIONS,1:200@A5 Once I saw the landforms in section, I realized they were more subtle than I had anticipated. As the majority of my landforming had been to reduce the slope towards the corner, the relatively flat surface seen in these sections was to be expected. However, despite being quite minor features, the geometric concrete forms do differentiate this site from the surrounding context and create a functional, multi-use space. I would like to continue this subtlety in my design for the big site.

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ORIGINAL LANDFORM 1:22 slope towards south east corner

INITIAL LANDFORMING Raising the rear of the site to prevent water pooling, and raising the site along Pelham St to guide water away from the corner

SLICING Use of geometric swale to slice through the topography, guiding water across site and creating a landscape feature.

TILTING Addition of geometric landforms around the periphery of the site to act as seating, climbable surfaces, and hydrological interventions.

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water water mov mov

vement vement

The landforming on site was utilized to influence water movement towards the swale.

Water is captured from the footpath and flows onto site following the direction of the contours. The raised concrete forms along Leicester St direct water along the footpath towards the start of the swale to lengthen the path the water travels along, and thus increase infiltration.

Trees were located along the edges of the swale so they have ample access to water, and to provided shade in the most exposed part of the site.

watershed,1:200@A5

Showing water disch The bridge connects the north-west corner of the site, which is essentially an exten phy at the rear of the site. Getting there requires crossing over the slice of greenery bridge takes you over the raingarden, which is located at the lowest point in the swa pedestrians, making this point the foca

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site site analysis analysis

PRIMARY CIRCULATION

These areas are predominantly flat (slight slope of 1:22 towards swale) so are ideal for pedestrian and disability access

SITE PERSPECTIVE 2

harge point from footpath, and bridge over raingarden. nsion of the footpath, with the more interesting topogray which divides the two paved spaces. Walking over the ale. The reeds are tall enough to reach up and envelop l point of the site for both human and water movement.

PAVEDSPACE/SKATINGZONES

The central open space is bounded by geometric concrete forms which can be used for reclining or by local skaters.

Phragmites au Common reed

DETAIL SECTION, 1:20@A5

Showing the low part of the swale which acts as a raingarden.

The base of the channel is gravel to allow for infiltration

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ustralis d

Carex tasmanica Curly sedge Juncus usitatus Billabong rush

Ficinia nodosa Knobby club rush Carex testacea Orange sedge

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THE THEBIG BIGSITE SITE

Feedback to look at going forward:

Push the idea of the artful expression of water movement Think about how you can continue to use landform to guide people’s movement through the site Work with different levels of water flow Up the ante! -

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My initial design exploration for the big site look at applying the geometric swale from assignment 1 to this new context. I very quickly realized however that the scale of the site required more refined interventions.

explorexploration ation

As a result of the swale cutting across the site, there became two distinct areas to the north and south. These had to be connected by equal access paths, which I integrated into the landscape (right). I did this to keep the surface mostly continuous, which was inspired by the Landhausplatz square in Innsbruck. In this way this site could also be skate-able. I tried to use this in further iterations.

In an attempt to break up the site into manageable pieces I began looking at a simple Voronoi pattern using Grasshopper to apply it to the surface. The idea was also that the form would mimic a dry, cracked riverbed, which was a comment I had received about the sliced form in my first assignment.

I then looked at various ways to connect the separate polygons to create a continuous surface that was habitable. I tried making each shape planar and connecting them with sloping sides, however these became too steep, particularly for disability access.

ABSTRACTEDMAPOFMELBOURNE

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OVERLAY ON VORONOI PATTERN

RESULTINGPATTERN RAINGARDEN FORM

NTOINFLUENCE M

form form development development Building on the use of pattern to define space on site, I looked at creating a cracked form through the centre of site in order to create a more centralized and considered design. This could act as open space during dry periods and become a series of rain-gardens during rain events.

I used a map of Melbourne and roughly traced the major roads to create an abstracted crack form, then layered this with a simple Voronoi pattern. The combined form is quite interesting and allows for development of large open space interspersed with more intimate experiences.

This form also gives the appearance of a dry riverbed or cracked desert surface, which relates to the idea of water that I am carrying through this subject. The site will be dry for the majority of the time, however during rain events these “cracks” will transform into channels that carry water.

One iteration I looked at used the shattered pattern to influence the placement of a series of terraces connected with equal access paths and steps (above), which can double as seating or skate-able surfaces. I didn’t find this successful, because despite creating an interesting experience and aiding in slowing down water movement, this form divides the park into small, separate spaces, and does not create a continuous experience.

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SECTION 1 5

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SECTIO N2

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MASTER PLAN 1:1250@A5

THE THEBIG BIGSITE SITE KEY

Vegetated areas

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High albedo concrete paving

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Ephemeral wetland (raingarden)

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Native trees and informal plantings

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ZONING Raingarden

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Equal access path

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Bridge over raingarden

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Lookout

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Raingarden “islands”

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Flat open space

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Water-capture channel along Swanston

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I used this cracked pattern to begin influencing the form on site. I started by manipulating the contours (below) to allow water to run into the centre of the site, for capture and infiltration. I then pulled the pattern onto the surface and used this design to place the raingarden, using the fractures between polygons as an outline. The raingarden was positioned so the majority of it ran diagonally across site, parallel to the contours in order to maximize capture of runoff. These fractures also became paths which criss-cross the site, including the equal access path that cuts across from the north-east corner.

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SECTION 1 1:1000@A5

SECTION 2 1:1000@A5 These two sections show the drop across the site . It is particularly evident in section 2 how the raingarden is recessed into the ground to allow for collection and infiltration of a large volume of rainwater.

This also creates a relatively flat space south of the raingarden, which contrasts with the sloping, hill-like form to the north.

The raingardens are traversed by a series of platforms connected with equal access ramps and perforated steel bridges that connect the different spaces. This creates changing experiences that all centre on the WSUD features on site.

Division of space 1:2000@a5 Open native grasslands

Activation of edge

Light scrub/tall native grasses

Most exposed area

Denser multi-story planting Ephemeral wetland species in raingarden Flat open space paved with high-albedo concrete

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CIRCULATION 1:2000@

Primary circulation Major PTV line

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EQUAL ACCESS 1:2000@A5 A) B) C) D) E) F) G) H) I)

10.3m 1:20 9.8m 1:14 19.6m 1:28 8.9m 1:14 8.5m 1:34 11.2m 1:14 11.6m 1:36 9.0m 1:14 9.0m 1:14

J) K) L) M) N) O) P) Q)

9.0m 1:18 13.0m 1:16 11.0m 1:18 7.9m 1:14 6.0m 1:15 7.3m 1:14 7.3m 1:14 7.3m 1:14

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mid-size shade trees

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Waterhousea floribunda Allocasuarina verticillata Flindersia australis Ficus macrocarpa

native grassland species

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Convolvulus erubescens Dichelachne crinita Danthonia caespitosa Poa labillardieri Themeda australis Chloris truncata

“messy” border planting

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Calocephalus lacteus Rhagodia spinescens Dianella revoluta

denser, multi-story planting

Adenanthos sericeus Austrostipa ramosissima Grevillea curviloba subsp. incurva Myoporum insulare

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site site axonometric axonometric

The series of ramps and bridges across the raingarden are best seen in the context of the rest of the site. The winding form creates a path from Swanston St, across the steepest parts of the site near the RMIT buildings, and down towards the flat open space near Victoria St. These steep areas are densely vegetated to influence pedestrian movement and prevent access.

1:750@A5

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Tussock - primarily keystone grasses

species diversity

Inter-tussock herbs - where the biodiversity is Perennial rootstock survives fire

plants plants & & management management over over time time I’ve chosen to use primarily Australian Native species to connect the site further to its indigenous and natural history through native revegetation of local EVCs, particularly the Western Victorian grasslands. I’ve selected a few keystone species such as kangaroo and wallaby grass, along with some inter-tussock perennial herbs such as Convolvulus erubescens, in the hopes of establishing an ecosystem analogue in the city. Low phosphorus topsoil will need to be brought onto site for these areas, or it can be scalped to remove excess nutrients and the seed (weed) bank. This will be a massive endeavor, but I believe it is an important part of our natural history, and something most Melbournians know little about.

In order to provide shade on site and help reduce surface temperatures in the city, I also looked at creating sections of multi-story planting. There’s a lack of dense native vegetation close to the city and through the implementation of these pockets, I hope to also support the native fauna species (possums, bats/micro bats, birds, native bees, etc) to promote a healthy ecosystem and increase biodiversity.

Due to the nature of the site and the cyclic pattern of drought and flood, I tried to select species that had a tolerance for both dry conditions and waterlogging.

The impending threat of climate change and rising temperatures, particularly in cities, means certain native species that have drought tolerant genetic traits could be more suitable in the long term. This is another reason I’ve specified a native plant palette.

This selection of species provides an opportunity to connect and collaborate with the Wurundjeri people in the management of the site. As fire is a catalyst for germination of some species and was used extensively across the basalt plains of Victoria to manage the grasslands, I believe using this space to allow for a small-scale native management intervention would provide an opportunity for reconciliation and learning.

Despite not having a current fire regime, there is potential to use cool burns on the site to help the natives stay dominant and keep the area healthy, as well as manage the balance of tussock and inter-tussock species in the grassland areas.

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disturbance is required to reduce biomass and shoot competition from dominant grasses - ensures biodiversity is maintained crypotogamic soil crust - moss, algae etc acts as weed suppression mat

time since disturbance

first year second year third year fourth year fifth year sixth year

Fire ecology management schedule 1:1000@a5

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WATERSHED DIAGRAM 1:1500@A5 Height of the land on site from high to low Location of the raingarden Pipes under footpath to capture water from the gutter Main flow of water on site through channel raingarden Overland flow of water

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As water is an important part of my design, I wanted to calculate - as accurately as possible - the volume I would be dealing with on site. I started with the catchment size of 6,800m2 which extends up Swanston St to the stormwater collection at Lincoln Square, and down to the start of the raingarden.

I looked at rainfall data for the nearest station in Olympic park and found that a rainfall event of 60mm has an annual exceedance probability of 10%. Looking at the daily rainfall data on site for 2020 so far, I saw that the largest event was 54.6mm, making me confident that designing for a 60mm rainfall event will be sufficient in most cases.

Using the catchment area and rainfall in mm, I calculated that the site would have to hold approximately 408,000L. Using a simple boolean and volume calculation in Rhino, I found that the raingarden can hold up to 409, 203L.

water volume calculations for site DAILY RAINFALL FROM OLYMPIC PARK STATION FOR 2020

60 mm

45 mm

30 mm

Highest day of rainfall, 54.6mm (05/03/2020)

15 mm

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changing changing water water conditions conditions on on site site While the site will experience dry conditions for the majority of the time, allowing for collection, purification and infiltration of stormwater in the urban environment helps reduce environmental degradation, while also increasing the aesthetic and recreational value of a space. The raingarden I’ve designed will be lush and biodiverse, creating a focal point on site that fluctuates with the changing environmental conditions. During dry conditions, the edges can function as seating and the dense planting is a beautiful, biodiverse landscape feature.

Above represents how the site responds to an average day of rainfall in Melbourne - roughly a 3mm rain event, resulting in 20,000L of water. Assuming minimal absorption of water along the raingarden, the volume shown would constitute that 20,000L entirely, however majority of the water would likely infiltrate as it moves through the site, so the collected water would probably be much less.

In contrast, the left image shows a rainfall event of 60mm, which is about the maximum volume of water the site can handle. The form of the raingarden and the dense planting works to slow the movement of water and increase infiltration, but the site also has the capacity to fill up and hold water if required.

perspective 1

view of raingarden

perspective 2

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ephemeral wetland species

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Juncus usitatus Carex tasmanica Lomandra filiformis Lomandra longifolia Podocarpus drouynianus This part of the site is central in my design, as the most experiential and central area, where people and water congregate. The ramps allow for people to walk right down to the edge of the raingarden, which during dry periods will be a sea of tussocky grasses, and during large rain events will fill up and form a temporal lake. I hope that this physical change will create intensive for people to visit the site throughout the year, during different weather conditions, to see how it changes and evolves in relation to external systems. The lookouts and changing levels allow people to experience this from different vantage points, further enhancing the fluctuations on site.

detail detail section section of of raingarden raingarden

1:200@a5

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perspective perspective 1 1 As Swanston St is the most heavily trafficked threshold due to the location of tram stops and bike paths, I wanted to focus activation of the edges along this side. I began by continuing the plane of the footpath into the site to create a seamless connection with the surroundings and mimic a traditional urban park.

However, I also placed a series of tree pits along the edge to help define the boundary, while also providing shade and referencing Melbourne’s’ iconic tree-lined boulevards seen in the nearby Carlton and Flagstaff gardens. The corton steel channel running along the footpath also delineates the edges of the site, while highlighting the beginning of the journey rainwater will take as it moves toward the raingarden.

Sections of this channel are capped with a corton steel grate to allow for disability access to the site.

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This section details the inlet point along Swanston St shown in Perspective 1. Water enters via pipes under the footpath and flows into the open corton steel channel running parallel to the footpath. This channel flows down Swantson Street towards the entrance to the raingarden, where the water then enters the system. This channel also captures overland flow of water, and diverts some water into the five tree pits placed along the road. In doing so, the channel is a functional water feature, which serves to irrigate the trees while also articulating the start of the WSUD system, allowing pedestrians to follow of the flow of water down into the site towards the raingarden.

water water movement movement

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perspective perspective 2 2

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REFERENCE LIST

Australian Bureau of Meteorology. (2020). “Daily Rainfall data, Melbourne (Olympic Park)”. Australian Bureau of meteorology.

Accessed October 9, 2020. http://www.bom.gov.au/jsp/ncc/cdio/ wData/wdata?p_nccObsCode=136&p_display_type=dailyDataFile&p_stn_num=086338&p_startYear=)

Australian Bureau of Meteorology. (2016). “2016 Design Rainfalls”. Bureau of Meteorology. Accessed October 7, 2020. http:// www.bom.gov.au/water/designRainfalls/#sec1q5

Coutts, A and Tapper. N. (2017). Trees for a Cool City: Guidelines for optimised tree placement. Melbourne Australia: Cooperative Research Centre for Water Sensitive Cities.

Conn, B.J. (1993) Natural regions and vegetation of Victoria, in: Foreman, D.B. and N.G. Walsh (eds), Flora of Victoria Volume 1, pp. 79–158, Inkata Press. Retrieved from: https://vicflora.rbg.vic.gov. au/static/bioregions/victorian-volcanic-plain

GHD Pty Ltd. (2012). “Edinburgh Gardens Raingarden”.

Landzine. Retrieved from http://landezine.com/index.php/2012/10/edinburgh-gardens-raingarden-by-ghd-pty-ltd/

Gillies, C. (2020). Traditional Aboriginal burning in modern day land management. Retrieved from https://landcareaustralia.org. au/project/traditional-aboriginal-burning-modern-day-land-management/

Melbourne Water. (2020). “Raingardens”. Melbourne Water.

Accessed August 25, 2020. https://www.melbournewa¬ter.com.au/ water-data-and-education/environmental-issues/why-we-need-savewater/tips-saving-water/raingardens

Melbourne Water. (2017). “Plants for raingardens, wetlands and swales”. Melbourne Water. Accessed August 17, 2020. https:// www.melbournewater.com.au/building-and-works/stormwater-management/detailed-design/plants-raing¬ardens-wetlands-andswales#close

Pascoe, B. (2014). Dark Emu (2nd ed.). Magabala books.

The University of Melbourne. (2012). Burnley Plant Guide, University of Melbourne, Parkville. Accessed August 6, 13, 20 and 27, 2020. www.bpg.unimelb.edu.au

Urban Tree Manual. (n.d.). “The Right Tree in the Right Place for a Resilient Future”. Urban tree manual vol, no. 15: 5-7.

Williams, N. (2019). Greening Landscapes HORT20027 Lecture 8 Semester 2 - 2019.

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