Biodiversity Sensitive Urban Design

Cities are increasingly considered important places for biodiversity conservation because they can harbor threatened species and because conservation in cities represents an opportunity to reconnect people with nature and the range of health and well‐being benefits it provides. However, urbanization can be catastrophic for native species, and is a well‐known threat to biodiversity worldwide. Urbanization impacts can be mitigated by urban design and development improvements, but take‐up of these practices has been slow. There is an urgent need to incorporate existing ecological knowledge into a framework that can be used by planners and developers to ensure that biodiversity conservation is considered in decision‐making processes. Here, we distill the urban biodiversity literature into five principles for biodiversity sensitive urban design (BSUD), ranging from creating habitat and promoting dispersal to facilitating community stewardship. We then present a framework for implementing BSUD aimed at delivering onsite benefits to biodiversity, and that is applicable across a range of urban development types and densities. We illustrate the application of the BSUD framework in two case studies focusing on the: (1) protection of an endangered vegetation remnant in a new low‐density subdivision; and (2) persistence of an endangered reptile in an established suburban environment.


Introduction
Cities are increasingly recognized as important places for biodiversity conservation, and can harbor a diversity of plant and animal species, including threatened species (Ives et al. 2016). They are also important places for conservation from a human perspective. Exposure to nature in cities delivers a remarkable range of health and well-being benefits, including stress reduction, reduced mortality, and improved cognitive development in children (Shanahan et al. 2015). Intriguingly, biodiverse green spaces may deliver greater benefits than less diverse spaces (Fuller et al. 2007;Pett et al. 2016). Biodiversity conservation in cities therefore presents a unique opportunity to reconnect urban residents with nature and its associated benefits.
However, urbanization has myriad impacts on biodiversity, including habitat loss and fragmentation, changes to resource availability, introduction of exotic species, alteration of local climates via the urban heat island, modification of natural disturbance regimes, and increased levels of chemical, light and noise pollution (Grimm et al. 2008). These changes lead to reduced species and genetic diversity, biotic homogenization (McKinney 2006), and loss of ecological function and ecosystem services (Radford & James 2013). Numerous emerging threats, such as those associated with the uptake of LED lighting and energy-efficient (but cavity-free) homes, are likely to have further impacts (Stanley et al. 2015). These impacts are long-lasting with little option for reversal, making urbanization one of the greatest drivers of biodiversity loss (McKinney 2006).
Fortunately, some of the negative impacts of urbanization can be mitigated by improvements to the design and construction of new developments, or through retrofitting existing development (Figure 1). Numerous examples of urban design with positive biodiversity outcomes exist (e.g., Hostetler 2012; Beninde et al. 2015;Ikin et al. 2015, and Table S1 online). However, uptake has been slow when compared to other environmentally focused design protocols. In the absence of a practical framework for incorporating existing urban ecological knowledge into urban design and development, planners and developers have little guidance about which design elements to implement, or how to balance biodiversity with other objectives. There is now an urgent need for an evidential urban design protocol that links urban design to biodiversity outcomes.
We propose a framework for incorporating ecological knowledge into urban planning, design and development to achieve onsite biodiversity benefits. This necessitates a fundamental shift in thinking from current practice, where biodiversity losses are "offset" somewhere else. Biodiversity offsetting delivers questionable ecological outcomes because retained patches face ongoing threats from the surrounding environment (Driscoll et al. 2013), and the offset is unlikely to ever adequately compensate for the losses incurred (Bekessy et al. 2010). Furthermore, offsetting ignores the place-based value of nature, and results in an unmitigated loss of nature in the places where urban residents live, work, and play.
In this Perspective, we outline five principles for biodiversity sensitive urban design (BSUD), and describe a framework for incorporating BSUD into urban development decision-making. Using two case studies, we demonstrate the application of BSUD to greenfield and existing urban environments.

A framework for BSUD
To achieve onsite biodiversity benefits, BSUD must mitigate the detrimental impacts of urbanization, while encouraging community stewardship of biodiversity by facilitating positive human-nature interactions. We have distilled relevant ecological knowledge for addressing the impacts of urbanization into five BSUD principles: (1) Maintain and introduce habitat. New developments can be planned to avoid habitat loss by prioritizing development in areas of low ecological value (Bekessy et al. 2012). Retaining and protecting existing vegetation during the development process can also be beneficial for biodiversity (Hostetler 2012;Ikin et al. 2015). Habitat can be enhanced or created in existing urban areas by using native plant species and increasing vegetation complexity (Ikin et al. 2015;Threlfall et al. 2016), adding green infrastructure (Williams et al. 2014) or incorporating critical resources and habitat analogues, such as habitat walls ( Figure 1C; Lundholm & Richardson 2010). Residential gardens can be significant habitat, so residentled wildlife gardening programs can make a valuable contribution to biodiversity (Goddard et al. 2010).
(2) Facilitate dispersal. Dispersal can be facilitated by adding animal movement infrastructure (Taylor & Goldingay 2012), or establishing habitat connectivity corridors through private and public land (Goddard et al. 2010). Care should be taken to avoid inadvertently facilitating the spread of invasive weeds and pests.
(3) Minimize threats and anthropogenic disturbances. The impact of weeds and exotic predators can be reduced by landscaping with indigenous plants and establishing pet containment programs (Ikin et al. 2015). Increased runoff and nutrient loads can be mitigated by vegetated swales and rain gardens, which also deliver biodiversity benefits. The impact of noise and light pollution can be mitigated by sound barriers (although take care that this does not affect dispersal), temporary road closures and dimming or reconfiguring street lights (Gaston et al. 2012). (4) Facilitate natural ecological processes. The disruptive effects of urbanization on natural cycles, ecological processes and disturbance regimes (Grimm et al. 2008) can be mitigated by providing adequate resources for target species, protecting and enhancing pollinator habitat, and planning to safely enable natural disturbance events such as fire and flooding.
(5) Improve potential for positive human-nature interactions.
Cities are human environments and public engagement is key to successful conservation (Cooper et al. 2007). Urban design can help facilitate local stewardship of biodiversity by providing "cues to care" (Nassauer 1995), creating opportunities for positive interactions with nature, and addressing conflicts between biodiversity and safety objectives (Ikin et al. 2015) or potential ecosystem disservices.
A key challenge for BSUD is providing a framework that is flexible enough to achieve biodiversity and urban development objectives, which are often competing. In this section, we provide some guidance for the implementation of BSUD, drawing on objectives-based decisionmaking processes (Keeney 1994; Figure 2).
Using this approach, the user first documents existing ecological values, and identifies biodiversity objectives for their site, considering both site and landscape contexts. Examples of biodiversity objectives include increasing the likelihood that threatened species will persist onsite or reintroducing viable populations of native species that are locally extinct. At this stage, development objectives for the site should also be identified, including dwelling targets, infrastructure requirements, and other environmental objectives (e.g., energy consumption or water quality standards). Next, potential BSUD actions are identified, based on the five principles discussed above, and assessed for their capacity to meet all specified objectives. Because it is driven by objectives, and not existing approaches, this process encourages creativity in the identification of potential actions (Keeney 1994), thereby facilitating innovation. Furthermore, because individual BSUD actions are evaluated for their potential to meet ecological and other objectives, this process provides a mechanism for users, including developers and planners, to resolve trade-offs between competing objectives.
To assess the capacity for BSUD to meet biodiversity objectives, those objectives must be measurable. Numerous metrics have been used to assess the impact of urban form on biodiversity, including vegetation cover and proportions of native and non-native species (Lenth et al. 2006). These measures are simple to obtain, but are proxies for the amount of "nature" in an area and don't directly measure biodiversity outcomes. We propose viability, or the probability that target species and ecosystems can persist onsite once development occurs, as a more direct and meaningful measure. This can be assessed using multiple methods, including, in increasing order of complexity: (1) Literature review -existing information may be sufficient to develop conceptual models capable of predicting whether an individual action will improve or worsen persistence probability (see Mata et al. 2016); (2) Expert elicitation -where insufficient or lacking, information can be elicited from experts (Burgman et al. 2011), as demonstrated in Case Study 1; and (3) Population viability analysis (PVA) -PVAs provide the most transparent framework for exploring how species persistence is linked to urban design, but require detailed data and can be troubled by uncertainty in estimates of the absolute risk of decline. Nevertheless, they are reliable tools for assessing relative risk (McCarthy et al. 2003), and can be legitimately used to compare alternative BSUD actions, as demonstrated in Case Study 2 (see Wintle et al. [2005] for another example of PVA to assess scenarios).
Although challenging, this step enables users to choose the action or actions that best meet biodiversity and other objectives in the final step of the framework. Tradeoffs may be necessary; for example, if there are conflicts between biodiversity and other environmental or development objectives, if biodiversity leads to disservices (Lyytimäki & Sipilä 2009) or if an action benefits one species, but is detrimental to another. Tools are available to assist with trade-offs (Joseph et al. 2009;Bekessy et al. 2012), however, transparent trade-offs are only possible where the biodiversity benefits of individual BSUD actions can be compared using a common metric.

Case Study 1. BSUD to protect native grasslands in greenfield development
We consider the hypothetical (but realistic) development of a 35 ha site in an urban fringe setting typical of those in northern and western Melbourne, Australia. The site, historically grazed by horses, is bounded on two sides by residential and industrial land uses, and by undeveloped agricultural land interspersed with native grassland remnants on its remaining boundaries.

Biodiversity values
A 5 ha remnant patch of critically endangered grassland exists within the site along one boundary. It is of significant ecological value and legislation will require that it is retained and protected. Because the remnant partially adjoins other remnant grasslands in adjacent properties, it additionally makes a contribution to landscape connectivity.

Biodiversity objectives
The primary ecological objective is to improve the viability of the native grassland remnant. The metric used G. E. Garrard et al. Table 1 Potential BSUD actions to enhance native grassland viability in low-density greenfield development to measure viability is the probability that the grassland persists in the same or better condition for 25 years.

Development objectives
The site is to be developed as a typical low-density residential greenfield development, and will be subject to minimum housing densities and green space provisions specified by local planning policy.

BSUD Actions
Potential BSUD actions were identified in the design, construction and inhabitation phases of development, and primarily address key threats to native grassland viability associated with disruption to fire disturbance regimes, introduction of invasive weeds and changes to abiotic conditions (Table 1).

Assessing BSUD
Estimates of the overall contribution of BSUD and partial contribution of individual BSUD actions to the grassland persistence were elicited in a workshop with five grassland experts, using a modified Delphi technique (Burgman et al. 2011). The elicitation process and expanded results are detailed in the supplementary material.
While there was variation between experts, all experts agreed that, if the grassland was in good condition, BSUD would contribute to a 0.31 increase in the probability of the grassland persisting without deteriorating when compared to a non-BSUD development ( Figure 3). The majority of this increase was attributable to BSUD actions undertaken to protect and manage the grassland during the construction phase of development. This effect was likely to be smaller for a grassland initially in poor condition.
(Note that urban development contributed to a marginal increase in the persistence of the native grassland, even without BSUD. This reflects expert pessimism about the capacity for grassland condition to be maintained in the absence of any weed or biomass management.)

Decide
All BSUD actions were considered to contribute to an improvement in the viability of the grassland remnant, so the final decision about which actions to take requires a trade-off between the biodiversity benefits provided and the costs of implementation (which may include financial costs and conflicts with other social and environmental objectives). It is impossible to compensate for losses associated during construction via any other means, so protection and management during this stage should be Conservation Letters, September 2017, 00(0), 1-9 Copyright and Photocopying: C 2017 The Authors. Conservation Letters published by Wiley Periodicals, Inc.

Figure 3
Expert elicitation results, showing the contribution of BSUD to the probability of persistence of a remnant native grassland in low-density greenfield urban development. Results are presented for grasslands initially considered to be in "good" and "poor" condition.
prioritized to ensure an improvement in the long-term viability of the grassland. Planning for appropriate buffers and adjacent land uses, and seeking to promote active stewardship through thoughtful design are also recommended to achieve biodiversity objectives in this case.

Case Study 2. BSUD for a threatened reptile in an established urban environment
We consider here a hypothetical situation in which managers are considering options for retrospectively applying BSUD principles to an existing urban environment to improve the viability of the striped legless lizard, Delma impar. In this simulated example, a lizard meta-population exists across four small grassland patches of 0.5, 1, 1.5, and 3 ha, embedded in a suburban matrix and separated by distances of 200 to 450 m. The size and distribution of patches reflects those of grassland remnants within the western suburbs of Melbourne, Australia.

Biodiversity values
The striped legless lizard is a grassland endemic, listed as nationally vulnerable due to historical and current habitat clearance. Limited dispersal ability and habitat requirements mean this species is sensitive to urban development. This species is present at low densities (6 individuals/ha) at three of the four sites, but the long-term survival of the meta-population is thought to be threatened by poor dispersal and ongoing threats from the urban matrix, including predation by cats and decline in habitat quality. Additional values include the native grassland remnants, which are nationally endangered and provide important refuge for other native grassland species.

Biodiversity objectives
The primary biodiversity objective is to improve the viability of the striped legless lizard. This will be assessed over a 25-year time horizon using three metrics: probability of persistence, population size, and probability of occupancy.

Development objectives
Potential BSUD actions should reflect the established nature of the surrounding suburban environment and community.

BSUD actions
Three potential BSUD actions were identified in discussion with two species experts: (1) creation of habitat corridors to facilitate dispersal; (2) improving habitat quality in existing patches; and (3) restricting domestic cats to indoors or confined outdoor runs.

Assessing BSUD
A formal PVA was used to assess the contribution of BSUD to lizard viability, and implemented in RAMAS Landscape (2003 v 1.0). BSUD actions were simulated by: (1) allowing dispersal between patches, which occurs with decreasing probability as the distance between patches increases up to a maximum of 400 m; (2) increasing the carrying capacity of individual patches; and (3) reducing the proportion of individuals lost to predation from 0.50 to 0.25. The modelling process and results are provided in detail in the supplementary material.

Decide
When considering BSUD actions in isolation, decreasing predation through cat containment delivered the biggest benefit to the legless lizard, regardless of which evaluation metric was used ( Figure 4). This action alone increased the probability of persistence from 0.06 to 0.88 ( Figure 4A). The largest benefits were gained when all three BSUD actions were applied, although habitat improvement and the creation of habitat corridors contributed to substantial increases in meta-population abundance and occupancy, respectively, when considered separately in combination with cat containment ( Figure 4B, C).
The creation of corridors is likely to pose significant challenges in an established suburban environment where private land ownership is the dominant tenure. These results suggest that cat containment combined with habitat improvement in remnant patches can deliver remarkably good outcomes when evaluated using probability of persistence and abundance, however this comes at the expense of patch occupancy.

Discussion
We have presented a framework for incorporating ecological knowledge into the planning, design and development of urban environments. This framework makes three important advances in the field of urban conservation planning. First, it seeks to achieve onsite biodiversity gains, which will be necessary for reversing biodiversity decline, and further, is important for reconnecting urban residents with nature and exposing them to the benefits it provides (Soga & Gaston 2016). Second, by seeking to achieve biodiversity benefits in any development, BSUD rises above the dominant land sparing/sharing debate relating urban development patterns to biodiversity outcomes (Lin & Fuller 2013), which is scale-dependent and can be difficult to apply in practice because development patterns typically lie somewhere between sparing and sharing. Third, because it explicitly links urban design to measurable biodiversity outcomes, BSUD provides a flexible framework for developers and planners to make transparent trade-offs between biodiversity and other socioeconomic objectives.
However, BSUD alone is insufficient to conserve biodiversity in cities while they continue to densify and expand. Land sparing is important for protecting remnant habitat and maintaining some ecosystem services (Stott et al. 2015). Furthermore, many species will require large, well-connected habitat patches to survive (Beninde et al. 2015). To maximize urban biodiversity conservation outcomes, BSUD should be implemented alongside strategic land planning (e.g., Bekessy et al. 2012), including specification for housing densities that minimize the urban footprint. Research investigating the effectiveness of BSUD at different scales and housing densities will make a valuable contribution to current understanding.
Critical next steps for BSUD include establishing regulation for minimum standards, and identifying responsible authorities, appropriate bridging organizations and project champions to help build cross-sectoral relation-ships and a trusted body of science. Incorporating BSUD into holistic performance tools, such as the Green Building Council of Australia's Green Star Communities and US Green Building Council's Leadership in Energy and Environmental Design, is a further opportunity.
Many questions remain. For example, what are appropriate targets for BSUD, and with whom will the responsibility for implementation lie? We believe it is reasonable to expect the proponent or developer to accept procedural and financial responsibility for implementing BSUD, as is the case for similar urban design schemes. Proponents could demonstrate adherence to biodiversity targets as part of the development approval process, with assessments undertaken independently by ecological consultants, either separately or as part of environmental impact assessments that are now standard precursors to development in many countries. PVAs are not beyond the capabilities of many ecological consultants; however, metrics such as abundance or probability of occupancy may suffice where data availability or technical expertise precludes viability assessment.
Science can provide information about the biodiversity benefits of BSUD, but decisions about performance targets, including which species and ecosystems to target and what minimum standards apply, are subjective and must be made by a regulatory authority on behalf of society. These targets would likely be guided by socioecological criteria, and BSUD offers a flexible framework in which biodiversity benefits can be transparently traded-off against other environmental, social and economic goals. Regardless of the target, BSUD has the potential to shape a new conception of urban landscapes, where species can thrive and residents reap the remarkable range of benefits that biodiversity can deliver. elicitation workshop was granted by RMIT University's Human Research Ethics Committee (Project number CHEAN A 0000018851-07/14).

Supporting Information
Additional Supporting Information may be found in the online version of this article at the publisher's web site:

Biodiversity Sensitive Urban Design
Biodiversity Sensitive Urban Design (BSUD) is a protocol for urban design that aims to create suburbs that are a net benefit to native species and ecosystems through the provision of essential habitat and food resources.
It represents a new approach to urban biodiversity conservation by seeking to achieve biodiversity benefits on site, in contrast to the standard offsetting approach, which reduces the opportunity for urban residents to engage with nature and, at the same time, delivers questionable ecological outcomes.

What is it?
What are the benefits?
BSUD aims to protect native species and ecosystems in the places where people live and work. Urban greening associated with BSUD also provides a range of proven benefits to individuals, communities and cities, including: • Cooling of urban areas • Air and water purification • A range of human health and wellbeing benefits in areas such as mental health, cardiovascular health, social cohesion and cognitive ability. • Increased worksplace productivity

Artist's Impression: Biodiverse Midrise for Fishermans Bend
How can I implement BSUD? BSUD can be implemented at a range of scales, and by a range of people, from individual home owners wanting to reduce their impact on nature, through to local and regional authorities responsible for the planning and development of major towns and cities.
BSUD proceeds in 6 steps, including an optional step allowing quantitative assessment of the contribution of the built environment to biodiversity.
• Determine which native species and ecosystems are present in or utilise the area, paying particular attention to any that are threatened. • Document the landscape context of the area, including geology, hydrology and any natural features of the landscape. Consider the role of the area for overall connectivity in the landscape. • Where the landscape is heavily modified, seek information from historical records about species and ecosystems that once existed there. This will provide information about which species may exist there again.
2. Define ecological objectives, such as : • Maintain viability of threatened species and ecosystems • Protect and restore habitat quality • Opportunities for rewilding

Photo by Peter Robinson
Maintaining or improving the viability of threatened species, such as the striped legless lizard, is a key environmental objective for BSUD.
Striped Legless Lizard 1. Maintain or create habitat for target species (feeding, nesting and protection; minimum patch sizes; landscape connectivity) 2. Facilitate dispersal of species 3. Minimise disturbance 4. Facilitate natural processes, considering the management requirements of target species and ecosystems (burning, weed control, mowing, etc.) 5. Facilitate positive human-nature interactions and engage the local community (creating "Cues-to-Care"; promoting active stewardship) Thoughtful design that engages the local community promotes active stewardship of nature in public places.
considering the five principles of BSUD: Identify actions required to achieve objectives, 4.
Green roofs and habitat walls provide habitat for native birds and insects.
Different types of habitats (eg. a mix of tall trees, shrubs and small plants) cater for a range of native species.
Domestic cats are a major threat to native animals like the striped legless lizard and should be contained at all times.
A reduced building footprint allows for more vegetated space, providing habitat and lessening barriers to animal movement.
Thoughtful creation of habitats offers many benefits. For example, creating habitat for the blue-banded bee will not only benefit native Dianella species, which depend on them for pollination, it will also help you by pollinating your tomato plants.
Image by Patricia Galan.

Quantitative assessment of contribution to biodiversity
This step will help to answer questions such as: "If I do this, this and this, how much will it benefit native species and ecosystems?" To arrive at an answer, you will need to assess the probability that the species or ecosystem can persist in the landscape. This can be measured using multiple methods, including, in increasing order of technical complexity: • Literature review • Expert elicitation • Formal population viability analysis.
Step 5 is optional, but has the added benefit of enabling the actions or suite of actions that provide most cost-effective biodiversity benefit (the most bang for your buck) in Step 6.
Identify the BSUD actions that best meet ecological objectives (Step 2), while also accommodating development objectives (Step 3) for the area.

6.
Population viability analysis is a useful tool for estimating the positive contribution of BSUD to native species and ecosystems. Native Grasslands in Melbourne's Urban Fringe The native temperate grasslands of the Victorian Volcanic Plain are amongst the most endangered ecosystems in Australia. More than 99% of the original extent has been cleared or converted to agriculture, and less than 0.1% remains in good condition. Much of the remaining grassland exists in areas designated as growth corridors for Melbourne, and thus, these grasslands and the species that inhabit them are threatened by urban development.
In this case study, our ecological objective was to maximise the likelihood of grasslands and a protected striped legless lizard persisting in new suburbs after development had occurred. We aimed to show how BSUD could improve the likelihood that native grasslands and the striped legless lizard, (Delma impar) would persist in new suburbs. We assessed the extent to which BSUD could contribute to persistence using expert opinion (native grasslands) and population viability analysis (striped legless lizard). We did not have specific development targets.
The BSUD actions examined were those that addressed major threats posed to native grasslands (loss and fragmentation of habitat, loss of species diversity caused by lack of burning and invasion by weeds, and poor public perception) and striped legless lizards (predation by cats, loss of habitat quality and quantity, and barriers to dispersal) in urban environments.

Conflict between grassland conservation and urban growth in Melbourne. Areas in green represent modelled native grassland
occurrence. Darker green = native grasslands more likely to occur. Designated urban growth areas are those between the urban growth boundary (red line) and established urban areas (grey shaded areas).

Outcomes
We identified aspects of BSUD that could improve prospects for native grasslands and striped legless lizards in all phases of development.
BSUD was estimated to more than double the probability of persistence of native grasslands in urban landscapes and the legless lizard was thought to stand little chance of persisting without it. BSUD during construction was thought to confer the greatest potential to improve persistence of native grasslands in urban environments, while design elements aimed at reducing predation by cats during the inhabitation phase were most effective for the striped legless lizard. Because of the heavily modified nature of the site, ecological objectives focus on rewilding; creating the habitat and resource availability to attract native biodiversity to the area. We focused on five native species including birds (brolga & spotted pardalote), a butterfly (dainty swallowtail), a frog (growling grass frog) and a micro-bat (striped free-tailed bat). These species were chosen for their charismatic characteristics (eg. Brolgas are large, spectacular water birds), potential co-benefits (eg. Bats and frogs are insectivorous and therefore help control pests like mosquitos, and butterflies provide residents with restorative psychological benefits), and feasibility of their ecological requirements (eg. Spotted pardalote are already resident in nearby Westgate Park, and the Dainty swallowtail has a preference for domestic nature such as citrus trees as well as native vegetation). We identified the habitat and resource requirements for these species, and incorporated them into the built environment through habitat walls, semi-private and public open space. • Height limits of 4-7 storeys to improve accessibility and connectedness to nature and streets. • Active streetscapes to improve safety and strengthen community. • Diversity of building typologies to ensure dwellings for a range of urban residents. • Incorporating Melbourne's unique city block and laneway features. • High quality living spaces, with average apartment size of 100 m 2 .

Outcomes
Our biodiverse mid-rise model achieves housing densities that are comparable to those identified for brownfield development sites in Plan Melbourne. However, when compared to the proposed high-rise development for Fishermans Bend, the sustainable mid-rise model will provide better urban design and human health and well-being outcomes, including better access to open space and improved streetscapes, a reduction in the urban heat island effect, a reduction in household energy use, and improved workplace productivity and childhood cognitive development. In addition, the wetlands required by some species provide additional water purification and flood mitigation services in a floodprone landscape like Fishermans Bend.

November 2015
This research was supported by The Myer Foundation, as part of the project "Reimagining the Suburb".  (3), s 39 (4) Protection of the Environment Administration Act 1991 (NSW) s 6(2), s 6(2)(a), s 6 (2)(b), s 6(2)(c), s 6(2)(d) Telecommunications Act 1997 (Cth) Sch 3, Pt 1, Div 3 cl 6(1)(b), Sch 3, Pt 1, Div 3 cl 6(3) This precautionary approach has been adopted by Telstra in its proposal. The nature and design of the antennas, their tilt and pan, the nature and quality of the radio equipment comprising the proposed base station and the efficient use of the equipment including the use of adaptive power control, all operate to minimise RF EME exposure: see also

104
No evidence was put forward to suggest that any RF EME exposure from the proposed base station was unnecessary or incidental to the achievement of service objectives or process requirements for the proposed base station. Dr Black stated there were no other precautionary measures that could be taken to further minimise RF EME exposure from the proposed base station and certainly none that could be readily achieved at reasonable expense.

105
Accordingly, the proposed base station meets the precautionary approach recommended by the Australian Standard RPS3.

106
Indeed, as was concluded in Vertical Telecoms Pty Ltd v Hornsby Shire Council [2000] NSWLEC 172 (10 August 2000) at [70], "the safeguards generally adopted, and applied to this proposal, are for more stringent than any research has shown to be necessary".

107
The issue of the effect of RF EME emitted from the proposed base station raises the question of the ecological sustainability of the development, and in particular the applicability of the precautionary principle to the development. I will first outline the basic concept of ecologically sustainable development and then its applicability to the determination of development applications under the EPA Act. I will next focus on the precautionary principle and its applicability to the proposed development in this case.

108
Ecologically sustainable development, in its most basic formulation, is "development that meets the needs of the present without compromising the ability of future generations to meet their own needs": World Commission on Environment and Development, Our Common Future, 1987 at p. 44 (also known as the Brundtland Report after the Chairperson of the Commission, Gro Harlem Brundtland). More particularly, ecologically sustainable development involves a cluster of elements or principles. Six are worth highlighting.

109
First, from the very name itself comes the principle of sustainable use -the aim of exploiting natural resources in a manner which is "sustainable" or "prudent" or "rational" or "wise" or "appropriate": P Sands, Principles of International Environmental Law, 2nd ed, Cambridge University Press, 2003 at p. 253. The concept of sustainability applies not merely to development but to the environment. The Australian National Strategy for Ecologically Sustainable Development makes this explicit in defining ecologically sustainable development as "development that improves the total quality of life, both now and in the future, in a way that maintains the ecological processes on which life depends": National Strategy for Ecologically Sustainable Development, Australian Government Publishing Service, 1992 at p. 8.

110
Secondly, ecologically sustainable development requires the effective integration of economic and environmental considerations in the decision-making process: see the chapeau to the definition of ecologically sustainable development in s 6(2) of the Protection of the Environment Administration Act 1991 (NSW) adopted by s 4(1) of the EPA Act and Principle 4 of the Rio Declaration on Environment and Development. This is the principle of integration it was the philosophical underpinning of the report Our Common Future. That report recognised that the ecologically harmful cycle caused by economic development without regard to and at the cost of the environment could only be broken by integrating environmental concerns with economic goals.

111
The principle of integration ensures mutual respect and reciprocity between economic and environmental considerations. The principle recognises the need to ensure not only that environmental considerations are integrated into economic and other development plans, programmes and projects but also that development needs are taken into account in applying environmental objectives: see P Sands, Principles of International Environmental Law, 2nd ed, Cambridge University Press, 2003 at p. 253.

112
The principle has been refined in recent times to add social development to economic development and environmental protection. The Plan of Implementation of the World Summit on Sustainable Development held in Johannesburg, 2002, notes that efforts need to be taken to: "promote the integration of the three components of sustainable development -economic development, social development and environmental protection -as interdependent and mutually reinforcing pillars. Poverty eradication, changing unsustainable patterns of production and consumption and protecting and managing the natural resource base of economic and social development are overarching objectives of, and essential requirements for, sustainable development": at paragraph 2.

113
Thirdly, there is the precautionary principle. There are numerous formulations of the precautionary principle but the most widely employed formulation adopted in Australia is that stated in s 6(2)(a) of the Protection of the Environment Administration Act 1991 (NSW). This provides: "…If there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation.
In the application of the precautionary principle, public and private decisions should be guided by: (i) careful evaluation to avoid, wherever practicable, serious or irreversible damage to the environment, and 115 This is the particular principle of ecologically sustainable development invoked by the Council and the residents in this case in aid of their opposition to the proposed base station. I will return to it shortly.

116
Fourthly, there are principles of equity. There is a need for inter-generational equity -the present generation should ensure that the health, diversity and productivity of the environment are maintained or enhanced for the benefit of future generations: see s 6(2)(b) of the Protection of the Environment Administration Act 1991; s 3.5.2 of the Intergovernmental Agreement on the Environment; and Principle 3 of the Rio Declaration on Environment and Development.

117
There is also a need for intra-generational equity. This involves considerations of equity within the present generation, such as use of natural resources by one nation-state (or sector or class within a nation-state) needing to take account of the needs of other nation-states (or sectors or classes within a nation-state): P Sands,

119
Sixthly, ecologically sustainable development involves the internalisation of environmental costs into decision-making for economic and other development plans, programmes and projects likely to affect the environment. This is the principle of the internalisation of environmental costs. The principle requires accounting for both the short-term and the long-term external environmental costs. This can be undertaken in a number of ways including:

122
The EPA Act is one such legislative enactment. It expressly states that one of the objects of the EPA Act is to encourage ecologically sustainable development: s 5(a)(vii). The Act defines ecologically sustainable development as having the same meaning as it has in s 6(2) of the Protection of the Environment Administration Act 1991.

123
Section 79C(1) of the EPA Act, which sets out the relevant matters which a consent authority must take into consideration, does not expressly refer to ecologically sustainable development. Nevertheless, it does require a consent authority to take into account "the public interest" in s 79C(1)(e). The consideration of the public interest is ample enough, having regard to the subject matter, scope and purpose of the EPA Act, to embrace ecologically sustainable development.

124
Accordingly, by requiring a consent authority (or on a merits review appeal the Court) to have regard to the public interest, s 79C(1)(e) of the EPA Act obliges the consent authority to have regard to the principles of ecologically sustainable development in cases where issues relevant to those principles arise: Carstens v Pittwater Council (1999)

The precautionary principle
The precautionary principle explored

125
I have set out in the preceding section on ecologically sustainable development, the formulation of the precautionary principle in s 6(2) of the Protection of the Environment Administration Act 1991 which is adopted by s 4(1) of the EPA Act: see paragraph 112 above.

126
A number of decisions in this Court have established that the precautionary principle is to be considered in making determinations of development applications under the EPA Act: Carstens v Pittwater Council (1999)

127
However, there has not yet been, in the decisions of this Court, a detailed explanation of the precautionary principle or the procedure for application of it. Hence, it is necessary to refer to other sources of information on the precautionary principle, including judicial decisions of other jurisdictions and the academic literature on the precautionary principle. Drawing on these sources, the following guidance can be offered on the concept of the precautionary principle and its application.

128
The application of the precautionary principle and the concomitant need to take precautionary measures is triggered by the satisfaction of two conditions precedent or thresholds: a threat of serious or irreversible environmental damage and scientific uncertainty as to the environmental damage. These conditions or thresholds are cumulative. Once both of these conditions or thresholds are satisfied, a precautionary measure may be taken to avert the anticipated threat of environmental damage, but it should be proportionate: N de Sadeleer, Environmental Principles: From Political Slogans to Legal Rules, Oxford University Press, 2005 at p. 155.

129
Two points need to be noted about the first condition precedent that there be a threat of serious or irreversible environmental damage. First, it is not necessary that serious or irreversible environmental damage has actually occurred -it is the threat of such damage that is required. Secondly, the environmental damage threatened must attain the threshold of being serious or irreversible.

130
Threats to the environment that should be addressed include direct and indirect threats, secondary and long-term threats and the incremental or cumulative impacts of multiple or repeated actions or decisions. Where threats may interact or be interrelated (for example where action against one threat may exacerbate another threat) they should not be addressed in isolation: see "Guidelines for applying the precautionary principle to biodiversity conservation and natural resource management", R Cooney and B Dickson (eds) Biodiversity and Our vision is that Melbourne will continue to be a global city of opportunity and choice.
Plan Melbourne's vision for the city is guided by nine principles.

Social and economic participation
Social mobility is essential for social cohesion. Victoria's challenge is to make it easier for every citizenregardless of their race, gender, age, sexuality or ability-to attain the skills they need to fully participate in the life and economy of the city and state.

Principle 3
A city of centres linked to regional Victoria The central city will remain the focus for global business and knowledge-intensive industries linked to an extensive network of clusters, centres, precincts and gateways. These physical, social and economic links will be strengthened, turning Melbourne into a city of centres linked to regional Victoria-creating social and economic opportunities across the state.

Principle 5
Living locally-20-minute neighbourhoods Creating accessible, safe and attractive local areas where people can access most of their everyday needs within a 20-minute walk, cycle or local public transport trip, will make Melbourne healthier and more inclusive. Due to the specialised and diverse nature of work, many people will still need to travel outside of this 20-minute neighbourhood for their jobs.

Principle 2
A globally connected and competitive city Melbourne will develop and deliver infrastructure to support its competitive advantages in sectors such as business services, health, education, manufacturing and tourism. Employment, research, retail, cultural and sporting precincts will also be supported to ensure Melbourne remains attractive and liveable.

Environmental resilience and sustainability
Protecting Melbourne's biodiversity and natural assets is essential for remaining a productive and healthy city. There is an urgent need for Melbourne to adapt to climate change and make the transition to a lowcarbon city.

A distinctive Melbourne
Melbourne has an enviable natural environment, important Aboriginal cultural heritage values, a rich inheritance of open space, and landmark buildings and streets created during the population booms of the Gold Rush and post-War period. To ensure Melbourne remains distinctive, its strengths will be protected and heritage preserved while the next generation of growth is planned to complement existing communities and create attractive new neighbourhoods.

Leadership and partnership
Melbourne's growth relies on effective governance, strong leadership and collaborative partnerships. Maintaining strong working relationships between all spheres of government, the public and private sectors and the wider community will ensure that all Melburnians share the benefits and the responsibilities of putting plans into practice.

Infrastructure investment that supports balanced city growth
Smart infrastructure investment and better utilisation of existing infrastructure is the key to creating new jobs and driving population growth in the right places. It is also vital for the social, economic and environmental wellbeing of the city. That's why there needs to be a pipeline of projects and initiatives that make Melbourne more sustainable, accessible and prosperous.

Strong and healthy communities
To remain a city of diverse, healthy and inclusive communities, Melbourne needs to ensure its neighbourhoods and suburbs are safe and walkable. Strong communities need affordable, accessible housing; local health, education and community services; access to recreation spaces; and healthy food.

Melbourne's 2050 plan
Plan Melbourne's vision for the city is guided by nine principles.
To support those principles seven outcomes have been set, together with the policy directions that will be taken to reach those outcomes.

4.5
Plan for Melbourne's green wedges and peri-urban areas

4.6
Strengthen community participation in the planning of our city

5.1
Create a city of 20-minute neighbourhoods

5.2
Create neighbourhoods that support safe communities and healthy lifestyles

5.3
Deliver social infrastructure to support strong communities

5.4
Deliver local parks and green neighbourhoods in collaboration with communities

6.1
Transition to a low-carbon city to enable Victoria to achieve its target of net zero greenhouse gas emissions by 2050

6.2
Reduce the likelihood and consequences of natural hazard events and adapt to climate change

6.3
Integrate urban development and water cycle management to support a resilient and liveable city

6.4
Make Melbourne cooler and greener 6.5 Protect and restore natural habitats

6.6
Improve air quality and reduce the impact of excessive noise 6.7 Reduce waste and improve waste management and resource recovery

7.1
Invest in regional Victoria to support housing and economic growth

Map 2
Melbourne 2050 Plan

INDEPENDENT ASSESSMENT OF PROGRAMS AND PROJECTS
Infrastructure Victoria was established in 2015. It provides independent expert advice to government on infrastructure plans and investment decisions, ensuring that projects are properly vetted and informed by rigorous, evidence-based advice.
In late 2016, Infrastructure Victoria released its 30-year strategy to the Victorian Government.
The Victorian Government has 12 months to respond and deliver its own five-year plan. This plan will inform decision-making on smart infrastructure projects and new services for delivery over the short, medium and long term-and influence the five-year review of Plan Melbourne. It is in the interests of all Victorians to ensure future infrastructure projects are chosen on merit. To protect and enhance river corridors, waterways, lakes and wetlands.

Strategies
Protect the environmental, cultural and landscape values of all water bodies and wetlands.
Ensure development responds to and respects the significant environmental, conservation, cultural, aesthetic, open space, recreation and tourism assets of water bodies and wetlands.
Ensure development is sensitively designed and sited to maintain and enhance environmental assets, significant views and landscapes along river corridors and waterways and adjacent to lakes and wetlands.
Ensure development does not compromise bank stability, increase erosion or impact on a water body or wetland's natural capacity to manage flood flow.
Protect the Yarra, Maribyrnong and Murray River corridors as significant economic, environmental and cultural assets.
Facilitate growth in established settlements where water and wastewater can be managed.

Consider as relevant:
Maribyrnong River -Vision for Recreational and Tourism Development (Melbourne Parks and Waterways, 1996) Maribyrnong

Catchment Overview
The Yarra catchment covers an area of 4046 square kilometres. About 55 per cent of the area retains its natural vegetation, 30 per cent is used for agriculture and 15 per cent is urban.
People of the Woi wurrung language group were the original occupants of this land and their descendants place enormous cultural and spiritual significance on the region's land and waters.
The catchment includes the Yarra (Birrarung) River, which is the largest river in the Port Phillip and Westernport region. The river rises in the Great Dividing Range to the east of Warburton and flows 245 kilometres until entering Port Phillip at Newport. The Lerderderg River and Yarra River, between Warburton and Warrandyte, have been identified as a Victorian Heritage River, meaning that it has significant recreation, nature conservation, scenic and cultural heritage attributes.
There are over 21,000 wetlands in the Yarra catchment, including approximately 16,000 constructed wetlands and nearly 5100 natural wetlands that support significant environmental and social values. More than one third of Victoria's native plant and animal species can be found in the Yarra catchment.
Population modelling shows that the Yarra catchment will increase from some 1.8 million people to over 2.4 million in the next 20 years, resulting in an additional 14,000 dwellings per year. The north growth corridor from Wallan to Broadmeadows, Mernda and Epping is the main growth area in the Yarra catchment. The Yarra catchment also encompasses part of the Fisherman's Bend urban renewal area, which is planned to become home to approximately 80,000 residents and provide employment for up to 80,000 people by 2050.
Poor quality stormwater inputs, drainage and clearing of vegetation have already impacted many wetlands of the Yarra catchment. Additionally the construction of levees and harvesting of water means that river-fed wetlands, including billabongs, are less frequently inundated and less able to act as nursery and breeding areas.
Increased discharges of stormwater, toxicants and litter can threaten the use of waterways and beaches for swimming and boating activities. Inappropriate development along the waterways can limit public access, overshadow the waterways, destroy floodplain habitat and change the character of waterways for the worse forever.

Catchment Overview
Population modelling shows that the Yarra catchment will increase from some 1.8 million people to over 2.4 million in The Yarra catchment covers an area of 4046 square the next 20 years, resulting in an additional 14,000 dwellings kilometres. About 55 per cent of the area retains its natural per year. The north growth corridor from Wallan to vegetation, 30 per cent is used for agriculture and 15 per cent Broadmeadows, Mernda and Epping is the main growth is urban. area in the Yarra catchment. The Yarra catchment also People of the Woi wurrung language group were the original encompasses part of the Fisherman's Bend urban renewal occupants of this land and their descendants place enormous area, which is planned to become home to approximately cultural and spiritual significance on the region's land 80,000 residents and provide employment for up to and waters. 80,000 people by 2050.
The catchment includes the Yarra (Birrarung) River, Poor quality stormwater inputs, drainage and clearing of which is the largest river in the Port Phillip and Westernport vegetation have already impacted many wetlands of the region. The river rises in the Great Dividing Range to the Yarra catchment. Additionally the construction of levees and east of Warburton and flows 245 kilometres until entering harvesting of water means that river-fed wetlands, including Port Phillip at Newport. The Lerderderg River and Yarra River, billabongs, are less frequently inundated and less able to act between Warburton and Warrandyte, have been identified as nursery and breeding areas. as a Victorian Heritage River, meaning that it has significant Increased discharges of stormwater, toxicants and litter can recreation, nature conservation, scenic and cultural heritage threaten the use of waterways and beaches for swimming attributes. and boating activities. Inappropriate development along the There are over 21,000 wetlands in the Yarra catchment, waterways can limit public access, overshadow the waterways, including approximately 16,000 constructed wetlands destroy floodplain habitat and change the character and nearly 5100 natural wetlands that support significant of waterways for the worse forever. environmental and social values. More than one third of Victoria's native plant and animal species can be found in the Yarra catchment. Figure 35 Sub-catchments and waterway assets including a sub-set of wetlands in the Yarra catchment  Bolin Bolin, "place of many lagoons" is a highly significant site to the Wurundjeri and is an integral part of the much larger cultural landscape.

RIVERS -Plenty Gorge Park, Plenty River
Plenty Gorge Park, with its significant natural and heritage features, offers a wide range of environmental, cultural and social experiences. This Community Vision will be given effect through both this Strategy and a separate document called the Yarra Strategic Plan. The Plan focuses on a more specific geographical area to the Healthy Waterways Strategy, concentrating on the Yarra River Corridor (rather than the whole of the Yarra catchment) and will consider public open space along the river, statutory planning, and the management of public land and infrastructure.
Achieving the Community Vision for the Yarra River relies on a healthy catchment. This Healthy Waterways Strategy has interpreted the Yarra River 50-year Community Vision to mean: Our Yarra catchment waterways are increasingly protected, respected and collaboratively cared for by Traditional Owners, government and community as living and highly valued entities. They are a linked network of thriving corridor and instream spaces which nurture biodiversity, deepen the relationship between people and nature, build resilience as our population grows and the climate changes, and contribute to wellbeing and liveability. Their ecological health and value to the community continuously improves through rehabilitated waterways and balanced uses.

VISION
The Healthy Waterways Strategy vision for the Yarra Catchment builds on the Yarra River 50 year Community Vision developed for the Yarra Strategic Plan in early 2018:

Yarra River 50-year Community Vision
Our Yarra River, Birrarung, is recognised around the world as an iconic example of a nurturing relationship between a river and its community.
Flowing from source to sea, it is the resilient lifeblood of past, present and future generations of Victorians. It connects and enriches our flourishing city, suburbs, regions and beyond.
Our Yarra River, Birrarung, its essential role in our lives and its rich history, are respected, understood and protected. It has cared for us for thousands of years and will for thousands to come.
The vital and continued role of Traditional Owners as custodians of the River, and its role in their culture, is recognised and celebrated.
Our Yarra River, Birrarung and its diverse surrounding landscapes provide a place of refuge, recreation, learning and livelihood. It brings communities together and supports sustainable local economies.
Its clean waters and connected network of thriving green spaces nurture biodiversity, and deepen the relationship between people and nature.
Our Yarra River, Birrarung is respected as a sacred natural living entity and everyone takes responsibility for its care. Its health and integrity are paramount and uncompromised.

Environmental
Bird species listed as nationally-threatened in the catchment include the swift parrot, Australasian bittern and helmeted honeyeater. There are 16 native fish species, including the nationally-listed dwarf galaxis, Macquarie perch (introduced), Australian mudfish and Australian grayling. Frog species include threatened species such as the growling grass frog and the brown toadlet. Two threatened species of frog, Bibron's toadlet (endangered in Victoria) and southern toadlet (vulnerable in Victoria) have seemingly disappeared from several areas in the catchment since the Millennium Drought.
Vegetation score is highly variable -the upper headwaters contain areas of very high value intact native vegetation protected within the Yarra Ranges National Park. Vegetation and macroinvertebrate scores decrease further from the headwaters as a result of agricultural activities and increasing areas of urbanisation.
Resilient and vulnerable populations of platypus have been observed across the catchment. A locally threatened population of platypus has been observed in the Plenty River in South Morang.

Social
Social value scores for rivers are currently high. The social value score for the estuary is very high. Social value scores are based on the surveyed level of community satisfaction and are threatened by inappropriate urban development, poor environmental condition, poor access to waterways and pollution.

Cultural
The land and waters of the region hold deep spiritual and cultural significance for Aboriginal peoples. The people of the Woi wurrung language group were the original occupants of this land, as evidenced by the thousands of cultural sites and places recorded, most of these occurring within 200 metres of a watercourse. Two significant sites include Bolin Bolin Billabong and Corranderk Aboriginal Station.

Economic
Major drinking water storages for Melbourne are located in the catchment. There are numerous diversions for domestic, stock and agricultural uses. Yarra Valley and Dandenong Ranges tourism is a significant economic driver, worth $559 million to the region's economy in 2015-2016.
114 Sub-catchment averaged by stream length (km)

Target
The targets developed through collaborative actions

Current trajectory
The likely outcome if current policies and effort continue Key value/condition is predicted to improve from current score Current key value/condition score is predicted to be maintained Key value/condition score is predicted to decrease from current

Targets and Performance Objectives
This section provides summaries of the long-term targets and performance objectives to be delivered through the implementation of the Strategy, in the 25 sub-catchments, sub-set of 20 wetlands and the Yarra River Estuary in the Yarra catchment. The full suite of targets and performance objectives are available in the Co-Designed Catchment Program for the Yarra catchment.

Rivers -Key values and waterway conditions (Yarra)
The following target summaries represent an average across the Yarra catchment for rivers.

Rivers -Summary of performance objectives (Yarra)
The following presents a summary of the 10-year performance objectives for rivers in the Co-Designed Catchment Program for the Yarra catchment.
• Progressively implement stormwater harvesting, focusing on rural townships along the Middle and Upper Yarra River, Woori Yallock, Olinda Creek catchments and new urban areas in the Merri Upper and Darebin Creek sub-catchments. Once this catchment has reached its anticipated long-term urban footprint based on the urban growth boundary, this will require around 37.8 GL/year of stormwater harvested and 10.7 GL/year infiltrated. Ensure DCI levels in the above priority catchments do not increase beyond current levels and headwater streams are retained as features in the landscape for environmental and social benefits.
• Investigate options to increase the environmental water reserve by 10 GL/year by 2028 to meet ecological watering objectives and cover projected shortfalls from climate change. This will benefit the middle Yarra River. Any water recovery for the environment will be considered through Victorian SWSs, markets and use of alternative water.
• Identify opportunities to maintain or improve the flow regime in refuge reaches to support instream values, including platypus.
• Reduce the key threat of flow stress by addressing the threats and other activities that impact waterways such as domestic, stock and agricultural uses, climate change, diversions or urbanisation.
• Establish 376 kilometres and maintain 1793 kilometres of continuous vegetated buffers (using EVC benchmarks and to at least a level 3 vegetation quality) along at least 80 per cent of priority reaches. In addition, increase vegetation cover in existing and planned urban areas by 2 kilometres to support social values.
• Maintain 735 kilometres of high and very high quality vegetation (vegetation quality levels 4 and 5) through effective monitoring and management of threats. • Increase access to and along waterways by 41 kilometres by improving connections with existing path networks and extending paths into new urban areas. Establish new boat launch facilities at key locations along the Yarra River to improve access for on-water activities.
• Reduce nutrient and sediment runoff from rural land through improved management of 1800 hectares of land including works to protect and increase vegetation along headwater streams.
• Provide connectivity for fish along major tributaries of the Yarra River through the removal of seven barriers by 2028. This will improve fish passage in several areas, including Darebin Creek and the Upper Yarra tributaries.
• Conserve all currently listed water dependent species and communities (16 fauna species, 150 flora species and 39 EVCs) through habitat protection, research and monitoring.

Rivers -Summary of long-term key value outcomes (Yarra)
The following target summaries represent an average across the Yarra catchment.
Birds score is currently moderate overall, with 252 bird species being recorded in the catchment including 153 species of riparian birds. Nationally threatened species include swift parrot, Australasian bittern and helmeted honeyeater. Without further action bird scores are considered unlikely to improve. The target is to maintain at moderate.
Fish scores are currently low overall, however the main stem of the Yarra is very important for native fish -with 14 indigenous freshwater species, including the nationally significant Australian grayling, Australian mudfish, and several estuarine species such as black bream, yellow eye mullet and mulloway. The fish score is considered likely to improve over time. The target is to improve the overall score from low to high.
Frogs score is currently low overall. Fifteen species of frog are expected to occur in the Yarra catchment. The nationally listed growling grass frog still occurs in some sub-catchments, mostly along north-western tributaries such as the Merri and Darebin Creeks. Frogs score is considered likely to decline unless the performance objectives in this strategy are achieved. The target is to improve to moderate.

Locations where a decline or very low score is expected: Darebin Creek, Plenty River Lower
Macroinvertebrates score is currently high overall. Diversity is higher along the main stem and in the middle and upper catchments. The target is to improve to very high.

Locations where a decline or very low score is expected for macroinvertebrates: Gardiners Creek, Merri Creek Lower, Koonung Creek, Mullum Mullum Creek
Platypus score is currently high overall for the catchment. Platypus are mostly found in tributaries of the middle and upper catchment and the main stem of the Yarra. Platypus are at risk, particularly in the lower and middle tributaries of the Yarra River, unless the performance objectives in this Strategy are achieved. The target is to maintain current populations at a high level. Amenity score is currently high based on community satisfaction, but is likely to decline in response to population growth and urbanisation. The target is to improve to very high.

Healthy Waterways Strategy 117
Connection score is currently high based on community satisfaction, but is likely to decline in response to population growth and urbanisation. The target is to maintain at high.
Recreation score is currently high based on community satisfaction, but is likely to decline in response to population growth and urbanisation. The target is to improve to very high.

Wetlands -Key values and waterway conditions (Yarra)
The following target summaries represent an average across the Yarra catchment for wetlands.

Wetlands -Summary of performance objectives (Yarra)
The following presents a summary of the 10-year performance objectives for wetlands in the Co-Designed Catchment Program for the Yarra catchment.
• Reduce the threat of invasive plant species.
• Deliver environmental water to key billabongs on the Yarra floodplain.
• Investigate opportunities to re-engage natural floodplain wetlands in key locations to meet ecological watering objectives, improve ecosystem services, cultural and social values.
• Reduce the threat of invasive animals such as dogs, cats and foxes to protect key wetland bird habitats.
• Develop understanding of the amenity, community connection and recreation values of wetlands and develop performance objectives to enhance these values.

Target
The targets developed through collaborative actions Reduce the threat of invasive plant species.
• Deliver environmental water to key billabongs on the Yarra floodplain.
• Investigate opportunities to re-engage natural floodplain wetlands in key locations to meet ecological watering objectives, improve ecosystem services, cultural and social values.
• Reduce the threat of invasive animals such as dogs, cats and foxes to protect key wetland bird habitats.
• Develop understanding of the amenity, community connection and recreation values of wetlands and develop performance objectives to enhance these values.

Wetlands -Summary of long-term key value outcomes (Yarra)
The following target summaries represent an average across the Yarra catchment for wetlands.
Wetland bird score in the Yarra catchment is on average currently very low. However, some wetlands such as Cockatoo Swamp have high bird values. Environmental watering of key billabongs in the Yarra catchment is predicted to improve the bird value of many billabong wetlands. The target is to improve from very low to low.
Locations where a decline or very low score is expected: Donnybrook Road Lake, Hearnes Swamp, Kalkallo Commons Grassland and Kalkallo Creek Wetlands, Growling Grass Frog Reserve Wetlands, Ringwood Lake, Lillydale Lake, Stormwater Wetlands, Anderson Creek East Retarding Basin Fish score is currently low overall. However, environmental watering of key billabongs and re-engagement of floodplain wetlands in the long term is predicted to significantly improve the fish score up to high.
Frogs score is high. Actions to reduce the threats of changed water regimes, altered wetland form, lack of wetland buffers and poor wetland vegetation condition will maintain the score at high, particularly in the Yarra billabongs. Many Yarra wetlands provide habitat for significant frog species such as growling grass frog. It is predicted that these habitats will continue to support these species.
Vegetation score is currently low. Actions to reduce the threats of changed water regimes, improve vegetation condition and wetland habitat form will improve the wetland vegetation score to a potential trajectory of moderate. 120

Estuaries -Key values and waterway conditions (Yarra)
The following target summaries represent an average across the Yarra catchment for estuaries.

Estuaries -Summary of performance objectives (Yarra)
The following presents a summary of the 10-year performance objectives for estuaries in the Co-Designed Catchment Program for the Yarra catchment.

Target
The targets developed through collaborative actions

Current trajectory
The likely outcome if current policies and effort continue Key value/condition is predicted to improve from current score Current key value/condition score is predicted to be maintained Key value/condition score is predicted to decrease from current

10-year performance objectives
• Enhance estuarine emergent vegetation condition that provides instream habitat.
• Reduce threat of invasive plant species to significant estuarine vegetation communities.
• Investigate opportunities to improve access for on-water activities and improve connections with existing path networks.
• Maintain recreational water quality within the Yarra estuary so that it is suitable for secondary contact (boating and fishing).
• Maintain existing high value facilities that support passive enjoyment and recreation.  16.5.9. Estuaries -Summary of long-term key value outcomes (Yarra) The following is a summary of the long-term key value outcomes for the Yarra River estuary.
Estuary birds score is currently very low due to the historical loss of habitat, industrial and urban development. The target is to avoid further decline.
Fish score is currently very high, with significant species such as the Australian Grayling using the estuary as part of its migration path between the sea and fresh waters. A good diversity of estuarine dependent fish species also inhabit the estuary. The target is to maintain at very high.
Vegetation score is currently very low due to the historical loss of habitat, and industrial and urban development. The target is to avoid further decline.
Amenity score is currently very high and is expected to remain very high with continued improvements to parks, facilities and vegetation.
Community connection score is currently very high. The Yarra River estuary is an iconic location loved by visitors and locals to Melbourne.
Recreation score is currently very high and will remain high. The estuary is a hub of activity including boating, cycling and walking. To assist the protection and conservation of Victoria's biodiversity.

Strategies
Use biodiversity information to identify important areas of biodiversity, including key habitat for rare or threatened species and communities, and strategically valuable biodiversity sites.
Strategically plan for the protection and conservation of Victoria's important areas of biodiversity.
Ensure that decision making takes into account the impacts of land use and development on Victoria's biodiversity, including consideration of: Cumulative impacts.
Fragmentation of habitat.
The spread of pest plants, animals and pathogens into natural ecosystems.
Avoid impacts of land use and development on important areas of biodiversity.
Consider impacts of any change in land use or development that may affect the biodiversity value of national parks and conservation reserves or nationally and internationally significant sites; including wetlands and wetland wildlife habitat designated under the Convention on Wetlands of International Importance (the Ramsar Convention) and sites utilised by species listed under the Japan-Australia Migratory Birds Agreement (JAMBA), the China-Australia Migratory Birds Agreement (CAMBA), or the Republic of Korea-Australia Migratory Bird Agreement (ROKAMBA).
Assist in the identification, protection and management of important areas of biodiversity.
Assist in the establishment, protection and re-establishment of links between important areas of biodiversity, including through a network of green spaces and large-scale native vegetation corridor projects. The Yarra River Corridor The Yarra River and Yarra Bend Park are of national biological significance. There are a further nine sites along the river that are biologically significant for Victoria.

River fauna
The Yarra River and its remaining billabongs support a rich diversity of fish including the nationally vulnerable Australian Grayling and the nationally endangered Macquarie Perch. Nine native fish species including the Australian Grayling migrate between the Yarra River and the sea as a necessary part of their lifecycle.
Platypus are occasionally sighted in the lower reaches of the river. More common and sometimes mistaken for Platypus is Rakali − a golden bellied native water rat. This small mammal has a long white-tipped tail and looks something like an otter with its webbed feet and waterproof coat.
Microbats use the river corridor by night to catch insects on the wing. They nest during the day in tree hollows. Thousands of Grey-headed Flying Foxes live in trees at Bellbird Picnic Area in Kew. At dusk they noisily leave their camp and use the reflected moonlight to follow the river before setting off across the suburbs in search of fruit and flowers. The Grey-headed Flying Fox is listed nationally as vulnerable to extinction. The Flying Fox is an important seed disperser and pollinator of both native and exotic trees.
The river and its riparian habitat provide nesting sites and food for various ducks and other waterbirds. Azure Kingfishers and Nankeen Night Herons are relatively common along the river and feed on small fish, insects and crustaceans. Small terrestrial birds nest in foliage and locally endangered Spotted Pardalotes nest in riverbank burrows. Several species of raptors have been recorded here too and their ongoing presence suggests a stable abundance of food.
Bluetongue Lizards, Gippsland Water Dragons and various snakes and skinks live amongst the reeds and vegetation along the river and are regularly spotted in gardens close by.

Vegetation
There is an almost unbroken corridor of vegetation extending along the Yarra River from Yarra Bend Park to Freeway Golf Course and beyond. This vegetation includes many rare and endangered plant species and eight of 12 threatened habitat types or Ecological Vegetation Classes (EVCs) found in Boroondara.

Key sites of significance along the Yarra River Corridor
Yarra Bend Park is Boroondara's premier site for nature conservation (Lorimer 2006). Its large area (143 hectares) is managed by Parks Victoria and supports a rich array of vegetation types. It is home to threatened habitats, seventy species of plants considered rare or threatened in Melbourne (and Victoria) including a critically endangered species of eucalypt Eucalyptus studleyensis. In addition to all the native animals that live in and around the river, the woodlands and grasslands on surrounding slopes provide habitat for insects and birds such as honeyeaters and hollow-dependent parrots. Grassy woodlands are an overlooked ecosystem in the state and country and even smaller remnants (such as those in Boroondara) make an important contribution to larger biodiversity goals beyond the City.