2018 Stormwater Victoria Conference

Awards for Excellence - 2016 Stormwater Victoria Winners

EXCELLENCE IN RESEARCH AND INNOVATION

Market Based Instrument to Maximise Environmental Benefit of Rainwater Tanks in Dobsons Creek
Melbourne Water, Waterway Ecosystem Research Group, Melbourne University, South East Water, Knox City Council and Marsden Jacob Associates

EXCELLENCE IN STRATEGIC OR MASTER PLANNING

Linking Geomorphology and Drainage System Design to Protect High Value Waterways
Alluvium Consulting Australia and Melbourne Water Corporation

Stony Creek Upper Transformation Project
City West Water Corporation, Greenfleet Australia, Brimbank City Council, Melbourne Water Corporation, Urban Renewal Authority Victoria (Trading as Places Victoria), Department of Environment, land, Water and Planning

EXCELLENCE IN POLICY OR EDUCATION

Green-Blue Ballarat Action Plan
City of Ballarat, E2Designlab, Aspect Studios, Department of Environment, Land, Water and Planning

EXCELLENCE IN INTEGRATED STORMWATER DESIGN

Warralily/Armstrong Creek Wetland and Creek System – Stages 2A-2F
Armstrong Creek Development Corporation Pty Ltd, Newland Developers Pty Ltd, GbLA Landscape Architects Pty ltd, City of Greater Geelong, SMEC Australia Pty Ltd, Neil M Craigie Pty Ltd, Australian Ecosystems Pty Ltd and Programmed Turnpoint Pty Ltd

Dobsons Creek is the highest value catchment within Knox City, with less than 2% of the catchment urbanised with formal stormwater drainage directly flowing into the creek. It has high environmental values with generally good water quality and vegetation cover and is home to a variety of native bird, frog, fish and other species.

Melbourne Water, South East Water and Knox City Council have been working to improve stormwater quality and flow objective for the creek and to reduce potable water use by residents. This is achieved through reducing the directly connected imperviousness (DCI) of the catchment which is correlated with the amount of harmful stormwater runoff discharging directly into the creek. The object is to reduce the DCI of the catchment by 2020 to a point where stream ecology starts to restore. In order to achieve this, disconnection needs to happen on public and private land.

Melbourne Water has been working with Melbourne University to design rainwater tanks and downpipe diverters so as to reduce the amount of stormwater flow leaving the property. Apart from outdoor uses, tanks will be plumbed indoors for toilet flushing and laundry, thus saving precious drinking water and reducing household water bills. In addition, the tanks are designed to be leaky, with dripper hoses connected midway along the tank height to disperse rainwater slowly into a garden or lawn. Overall, the design maximises the use or retention of stormwater on the property.

In Round 1, commencing in 2013, property owners in the upper Dobsons Creek catchment were offered rainwater tanks as described above free of charge. Round 1 of the project facilitated effective works on 95 properties, around 20% of eligible properties.

In Round 2, Melbourne Water trialled a household tendering system called a Market Based Instrument (MBI) to investigate whether the effectiveness of the program could be increased and cost reduced. In this approach:

Expressions of interest were obtained by mail drop, door to door and phone call marketing. Information was also made available on company website.
Households registering interest were contacted and site visits completed reporting on the suitability of the site for rainwater tanks, the recommended number of tanks and of indoor connections, the connected roof area and the estimated cost of installation.
Interested householders were then contacted for tender bids, their offer to financially contribute. To encourage participation, bidders were advised that they could either pay in full upfront or in four monthly instalments.
The bids were assessed against calculations of environmental benefits resulting from the tank installation and either accepted or rejected.
Tanks were scheduled for installation once payment was received for either the full amount of the bid or the first instalment

Bids were received from 53 of the 63 households that received site visits, of which 39 were accepted based on cost effectiveness comparison with the cost of delivering stormwater disconnection on public land in the Basin. Subsequently six households subsequently withdrew from the program leaving a final participation of 33 households.

Linking Geomorphology and Drainage System Design to Protect High Value Waterways
Alluvium Consulting Australia and Melbourne Water Corporation

Alluvium and Melbourne Water have developed an innovative approach to enhance sustainable waterway management in geomorphically fragile and challenging greenfield development landscapes. The approach moves beyond best practice waterway and stormwater planning and design, to truly account for and protect high value waterways from accelerated erosion triggered by stormwater flows.

The Sunbury growth corridor in north-west of Melbourne is planned to undergo rapid and large-scale greenfield urban development, with the population expected grow by approximately 42,500 residents expected to move to new residential developments over the next 25 years.

Melbourne Water are responsible for managing stormwater runoff to protect receiving waterways and Port Phillip Bay. This is achieved through surface drainage system planning under the Metropolitan Planning Authority’s (MPA) Precinct Structure Plans (PSPs) and Melbourne Water’s Development Services Schemes (DSSs). Through these processes, Melbourne Water have developed best practice objectives that focus on peak flow reduction for flood protection, referred to in this submission as the business as usual approach.

This study focussed on two PSP areas in Sunbury around the Jacksons Creek and Emu Creek. The geological features of the area include a basalt cap over highly erodible marine sediments punctuated by remnant volcanic cones, deep river valleys and steep basalt escarpments. The drainage network is highly fragmented and dominated by short, steep tributaries that support a plethora of geomorphic and ecological values, including rare River Styles classifications and threatened flora and fauna communities.

With many of these tributaries highly erodible and some currently undergoing incision, the erosion risk of the waterways and loss of values under post-development conditions is consistently high. The creation of new urban developments in this landscape presents a significant engineering challenge, and Melbourne Water’s business as usual approach was identified as being insufficient to meet their waterway protection objectives.

In order to plan and design a surface drainage system that overcame the challenging landscape and would protect the high-value waterways, Alluvium in collaboration with Melbourne Water developed an innovative approach that aligns with the critical PSP and DSS processes and moves beyond best practice.

The project has developed a landscape concept (Master Plan) and functional design for the rehabilitation of the reach of Stony Creek between Gilmour Road to Furlong Road in Sunshine North and the adjoining retarding basin. The rehabilitation design will improve waterway health (through removal of the concrete channel and replacement with more natural, vegetated waterway), provide stormwater treatment and harvesting, improve flood protection and provide a high quality community recreation asset. It has also confirmed that it is feasible to rehabilitate the reach in a series of stages and the Design has optimised land use on the site.

This project is an example of how multiple partners are coming together to deliver ‘real on the ground’ health and liveability outcomes. This project is a first for Melbourne Water where it has sufficient land to transform a concrete channel back into a natural waterway within a built up urban environment. It is also a first in the southern hemisphere where a purpose made ‘community cool zone’ will be created along the banks of the creek. This will be done by watering the banks in the days leading up to a heat wave event to promote soil moisture and evapotranspiration of the vegetation. This will in turn create a cooling of the microclimate.

Green-Blue Ballarat Action Plan
City of Ballarat, E2Designlab, Aspect Studios, Department of Environment, Land, Water and Planning

The green-blue Ballarat action plan is a landmark project that has begun to drive much greater integration
between 'green' infrastructure planning (trees, open space, landscapes) and 'blue' infrastructure planning
(stormwater quality, flow and alternative supplies) to achieve mutually beneficial outcomes. By designing
landscapes to benefit from irrigation using stormwater, the city will benefit from thriving ecosystems, year-round recreational spaces and attractive streetscapes. Equally, through integrated design, green assets can provide stormwater treatment and remove excess flows from waterways and drainage systems.

The first council strategy of its kind in Victoria which purposely set out to examine joint outcomes between
urban greening and water management policy implementation, the action plan has been widely commended
and has already demonstrated a shift in thinking at council – with officers and managers seeing the wider
benefits of green-blue approach.

Through natural processes, landscapes and water are inextricably linked. However, planning and management
processes for landscapes and water are often separated, involving different council budgets, officers and
stakeholders. The action plan identifies the cross-benefits that can be delivered by designing for both green and
blue outcomes, rather than focussing on one. A simple example is the design of streetscapes. Trees are often
planted in a small tree pit within the footpath, while kerb and channel drainage is installed to drain stormwater
runoff. By designing the tree and the drainage in tandem, much improved outcomes can be achieved for both
systems – the tree can enjoy a passive irrigation source, increasing health and resilience, and the drainage
system can be benefit from treatment provided by vegetation and soils in a tree pit system and from moderated runoff flows.

The action plan represents an important change in policy for City of Ballarat which is underpinned by a series of
demonstrative business cases and concept designs, a capital works plan and a spatial delivery strategy. From
the outset it was recognised that the success of the approach would depend on:

Driving action not loose promises – Purposely, an action plan was developed that would identify and develop delivery plans that could be immediately implemented by council – going further than a ‘strategy’ which risked being too high level to be embraced by officers and designers implementing projects on a day-today basis.
Integrating disciplines and roles – The scope of the action plan was mirrored by combined skills the consultant team engaged to complete the project (mixing expertise in stormwater management (E2Designlab) with landscape architecture (Aspect Studios)). An integrated stakeholder group was also developed to inform the project who are involved in both water management and urban landscapes.
Getting buy-in at all levels – A special taskforce oversaw the project, representing key managers at City of Ballarat, Central Highlands Water, DELWP and the local Catchment Management Authorities. The action plan also worked closely with the delivery and management teams within council, making sure aspirations could be delivered on-ground.

The action plan has been adopted by City of Ballarat and referenced in the overarching Ballarat Strategy to
inform future investment and practice in Ballarat.

Warralily | Armstrong Creek Wetland and Creek System - Stages 2A-2F
Armstrong Creek Development Corporation Pty Ltd, Newland Developers Pty Ltd, GbLA Landscape Architects Pty ltd, City of Greater Geelong, SMEC Australia Pty Ltd, Neil M Craigie Pty Ltd, Australian Ecosystems Pty Ltd and Programmed Turnpoint Pty Ltd

The Warralily development is a significant greenfield fully master planned residential development (794ha) within the City of Greater Geelong Urban Growth Zone. It incorporates the following key elements:

Major activity centre (137,000 sqm) of retail, non-retail commercial and community services floor space

Neighbourhood Activity Centre (6,000 sqm) of retail, non-retail commercial, community services

Local Activity Centres incorporating 1,000 sqm) of convenience shops and services.

Three Schools
Sporting Fields
Open space for passive and active recreation
Conservation Reserves
Waterway rehabilitation
Constructed wetlands and waterways

Armstrong Creek is an ephemeral waterway system that bisects the Warralily site from its western to eastern boundaries. Prior to European settlement it was widely utilised by the Wadawurrung people as a place to live, providing a rich source of food, meeting and gathering spaces and provided a significant means of travelling throughout the region. Since European development, the creek and surrounding areas have been significantly degraded by farming practices leaving a large portion of the waterway devoid of vegetation both in stream and on the adjoining banks or flats. The creek was effectively reduced to a table drain around the boundaries of the farming properties with little to no biodiversity values.

The rejuvenation of over 2.8km of Armstrong Creek and its immediate environs represents a significant waterway, biodiversity, public amenity, habitat creation and improvement project. The portion of Armstrong Creek that runs through the Eastern Precinct waterway and open space corridor varies from 70 – 150 metres in width and fulfills a number of key water quality, flood management, public amenity and key environmental systems objectives. The constructed waterway system combines online wetlands, sedimentation ponds, bio-retention systems open water pools, rocky riffles and ephemeral creek channels designed to capture, treat and retard stormwater from the surrounding urban catchment.

The restoration of the environmental processes of Armstrong Creek has been based on a detailed land capability assessment and broader understanding of the hydrological, environmental, social and economic context of the site. Key sites of ecological and cultural significance have been left largely untouched from disturbance whereby the design methodology has been based on protection and enhancement of existing vegetation and habitat qualities.

Other areas of the Warralily site possessed little or no ecological or cultural values and a significant re-construction of environmental processes has occurred. We have not attempted to recreate the more intact sections of the creek further upstream, rather as part of the rehabilitation process we have re-constructed sections of the old creek on a slightly different alignment and have introduced greater habitat diversity by introducing permanent and ephemeral pools with different depths and edge treatments both above and below the water line that provide a variety of different habitat opportunities for local wildlife.

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