Training Seminar 6 - Truganina

Session Information

Case Study Site: Truganina, Victoria

Recorded on Thursday 6 February 2020 | 12pm ADST

Instructions

The Truganina precinct has been adopted as part of the focus area for a recent Scenario Tool case study. The purpose of this case study is to consider how specific interventions of urban form and water servicing in greenfield development areas can support the delivery of integrated water management outcomes. The rapid transformation of Melbourne’s west is impacting on the water cycle of this region, and there is keen interest amongst government stakeholders to investigate how strategic changes to urban planning and development may help to resolve challenges the regional water balance is facing due to population growth and climate change.

The Truganina PSP describes the vision for Truganina and ensures the delivery of key local infrastructure to promote accessibility and community activity within the precinct. In this seminar, we will use part of the Truganina PSP with the Scenario Tool to model the urban water cycle for the specified area of mixed land uses and quantify the potential reduction in water sourced from the water supply system as a result of the implementation of various alternative water sources. In total, five scenarios will be produced: the baseline conditions detailing the current state of pre-developed Truganina, a business-as-usual case reflecting the proposed development of Truganina owing to existing planning policies and schemes, and three intervention scenarios that each feature different alternative water source systems.

Truganina - Urban Water Cycle

Model Setup

  1. Before beginning, use this Dropbox folder to access the GIS data employed as part of this seminar

  2. To start, navigate to the Scenario Tool website and log in using your registration details (otherwise register for the tool and then proceed to log in)

  3. At the project dashboard, create a new project, name it, and set the region to Melbourne

  4. Select the land surface temperature and water balance modules

  5. Upload the boundary file that is part of the GIS dataset previously referred to

  6. Submit the project to initialisation it

  7. Upload the remaining GIS files after reaching the project dashboard

Scenario 1 - BAU

This scenario represents the business-as-usual approach, incorporating a mix of different land uses and serving as the case that will be subjected to the implementation of alternative water source schemes.

Note

The nodes, their parameters and the GIS layers used with them have been informed from a combination of relevant literature and government authority input. As part of this seminar, the specific documentation for each node should be read to gain an understanding of its function and the resources used to calibrate it.

To prepare the business-as-usual scenario, begin with the ‘Residential’ node, using the ‘residential.geojson’ file as the area of effect and the parameter set below; then, follow the relevant table to set up the rest of the scenario.

  • City block width: 80

  • City block length: 240

  • Street offset: 8

  • Parcel width: 35

  • Parcel length: 35

  • Building height: 6

  • Site coverage: 0.6

  • Residential units: 1

  • Hardstand fraction: 0.5

  • Garden fraction: 0.8

  • Tree canopy diameter: 7

  • Percentage of lots with trees: 0

  • Number of trees per lot: 0

  • Street tree spacing: 13

Workflow Node

Light Industrial Zone

Educational Zone

Active Open Space

Assign Fractions

Assign Fractions

Area

Industrial

School

Recreational Reserve

Road

Other Pervious Area

Employee/student count

2800

1700

n/a

n/a

n/a

Tree Cover

n/a

n/a

n/a

0

0

Water Cover

n/a

n/a

n/a

0

0

Grass Cover

n/a

n/a

n/a

0.25

0.9

Irrigated Grass Cover

n/a

n/a

n/a

0

0

Roof Cover

n/a

n/a

n/a

0

0

Road Cover

n/a

n/a

n/a

0.5

0

Concrete Cover

n/a

n/a

n/a

0.25

0.1

Scenario 2 - Water Recycling

The first intervention scenario centres on a water recycling system, which collects wastewater from the entirety of the case study’s population and supplies it as reclaimed water to all industrial lots.

  • Parent scenario: BAU

  • Workflow node: Water Recycling

  • Area: Industrial

  • Uptake percentage: 100

Scenario 3 - Water Recycling + RWHT

The second intervention builds off the first, with residential lots now gaining access to rainwater for non-potable reuse.

  • Parent scenario: Water Recycling

  • Workflow node: Rainwater Harvesting Tanks

  • Area: Residential

  • Uptake percentage: 70

Scenario 4 - Non-potable Reuse

The third intervention adds a stormwater harvesting scheme that irrigates half of the public open space regions to the existing wastewater and rainwater initiatives.

  • Parent scenario: Water Recycling + RWHT

  • Workflow node: Stormwater Harvesting

  • Area: Recreational Reserve

  • Uptake percentage: 50

Scenario 5 - Potable Reuse

The final intervention substitutes the non-potable rainwater harvesting tanks previously implemented for potable rainwater reuse.

  • Parent scenario: Water Recycling

  • Workflow node 1: Stormwater Harvesting

  • Area 1: Recreational Reserve

  • Uptake percentage 1: 50

  • Workflow node 2: Potable Rainwater Harvesting

  • Area 2: Residential

  • Uptake percentage 2: 70

Results

You should have access to tiles depicting: the location and duration of the precipitation time series data used within the modelling; water demands; water being recycled within the project area’s water supply system; and the overall water balance of the catchment. The bar graphs comprising the tiles will allow you to witness how the different scenarios compare in terms of the various elements of the urban water cycle.