Discussion

Variable flood hazards have been combined to visualise areas of greatest risk. These variables in situ in Figure 8 are classified on the 1-5 rating scale discussed earlier, clearly indicating risk is concentrated in coastal and southern areas, with the risk retracting toward the outer perimeter of greater Melbourne.

The hazards underlying these areas of risk are mapped in Figure 9, and are most prominently attributed to three key classes in this local context:

Land use: the urban-rural gradient indicates reductive impervious surfacing from inner-city to peri-urban areas, generally trending south to north

Geology: stark delineation of rock attributes from lowest percentage porosity to highest from east to west, a feature of Melbourne’s volcanic sand-belt legacy

Elevation: the very flat landscape of inner Melbourne and coastal areas is contrasted against the higher elevations in the north, illustrating the low topography of the urban areas.

While these results are expected individually, when overlayed they offer powerful visualisations of these concentrated hazards. Vulnerabilities to infrastructure and human population have been illustrated in Figure 10, targeted for their criticality for population movement. A key contrasting attribute is population density, which is almost entirely confined to inner Melbourne.

Of note across all figures, Richmond SA2, part of City of Yarra is referenced, including vulnerable infrastructure (train stations) and populations (aged care, hospitals, schools). Vulnerabilities and hazards are combined to narrow our focus to regions at greatest risk, shown in Figure 12. Based on this, key focus areas for flood planning and evacuation management suggest The Cities of Yarra and Wyndham, each with two SA2 regions in the top 5 highest risk.

Across all figures, Richmond SA2, part of City of Yarra is referenced, including vulnerable infrastructure (train stations) and populations (aged care, hospitals, schools). Richmond includes arterial roads, and multiple public transport routes including trams and trains, including a main interchange at Richmond Station. At risk is industry - including large manufacturing factories and three of the 82 activity centres in the Melbourne 2030 strategy, and a world-class sporting precinct to name some of the key longevity streams (Wikipedia, 2019).

Based on 2016 Census Data, The City of Yarra has a population three times higher than City of Wyndham (Australian Bureau of Statistics, 2016). Coupled with its rich source of industry, Richmond must have the funding and resources to respond effectively to the recommendations, with funding strategies that can deliver climate change adaptation, as well as response planning.

Vulnerable population - schools (children), hospital (sick), retirement villages (elderly) are illustrated in figures 13-15. Converse to the highest risk areas, hospitals and schools with lowest risk should be targeted for evacuation planning.

Of the lowest risk potential crisis points, the closest for both the City of Yarra and the City of Wyndham are Mercy Public Hospital and Epping Secondary College - centres that should be included in disaster management planning.

Potential crisis centres - hospitals and schools at lowest risk

Lowest risk hospitals Lowest risk schools

The Northern Hospital St Thomas More’s School

Based on the findings of flood risk analysis, the following recommendations are presented as a viable guideline concerning flooding disaster management. A comprehensive framework of emergency response (Cova, T. J. 1999), has been referred to with the incorporation of GIS analysis tools for disaster mitigation, preparedness and response. An account of existing and accountable authorities have been identified with roles to ensure the mitigation in regions at high risk of flooding:

Department of Environment, Water, Land and Planning

Victorian State Emergency Services (VICSES)

VIC Roads

Catchment Management Authorities

Country Fire Authority

Melbourne Water

Bureau of Meteorology (BoM)

Ambulance Victoria

Australian Red Cross

Local Municipal Councils

Provide access to flood prediction technology, support strategy implementation

Manage Road Closure

Develop floodplain management, maintenance of levees, access to flooding intelligence technology

Support crisis management, Support shelter facility and communities

Work with VICSES and Local Councils to establish municipal response strategies

Support VICSES, flood prediction agency

Response to emergency calls, support relocation of health and age care facilities

Support Victorian Police and Ambulance Victoria

Support strategy plans and liaise with VICSES, other emergency services and assist in river levees and gauge maintenance

It is recommended that analysis and review of management plans are to be frequented every three years to ensure relevant arrangements and viable solution. The following is a developed subdivision of advisory responses has been developed for the Victorian State Government; This entails matters on population movement, industry response, environmental impact statements and infrastructure management in the Greater Melbourne area.

1. Population Movement

To direct population away from areas of high risk, train stations, tram lines, bus routes and main roads will be blocked or cancelled in service. This will be done in order to ensure people are deterred from flooding risk. It is the duty of VICSES to communicate emergency warnings and recommendations to Public Transport Victoria and VicRoads to block transport services and access in coordination with Victorian Police in affected municipalities. It is the duty of VICSES, Bureau of Meteorology (BoM)and Melbourne Water to communicate emergency warnings via telecommunications. Flood forecasting, prediction agency and emergency information are to be updated with issues of official forecasts by VICSES and BoM. From findings of analysis the following stations have been flagged as high risk and should be immediately prioritised in blocking access and services:

I. East Richmond (Alamein, Belgrave, Glen Waverley and Lilydale lines) II. Burnley (Alamein, Belgrave, Glen Waverley, and Lilydale lines) III. Kensington (Craigieburn line) IV. Heyington (Glen Waverley line) V. Middle Footscray (Sunbury)

Trams lines connected to train station lines are also to be disrupted from service in areas of high risk as deemed by VICSES. Hospitals and Schools at low risk are to be incorporated as locations for emergency shelter and additional health aid and services to be provided for. This include lowest risk hospitals and schools with appropriate capacity of emergency services are:

The Northern Hospital (Epping Mercy Public Hospital (Heidelberg) The Bays Hospital (Mornington) St Thomas More’s School (Hadfield) Ferny Creek Primary School (Ferny Creek) Epping Secondary College (Epping)

2. Industry Response

It is recommended to the State Government to initiate a program to create a flood emergency warning committee. This is recommended to be piloted in the region of Greater Melbourne due to findings of high levels of risk due to rising sea-levels and historic events of flash flooding. As BoM is a leading organisation for flood forecasting and warning services, it is essential for their participation. The committee suggested are:

I. Department of Environment, Land, Water and Planning II. Bureau of Meteorology (Chair/Secretariat) III. Victorian Rural Water Authorities IV. Victoria State Emergency Service, V. Local Government VI. Melbourne Water VII. Other State Government agencies (as required).

The purpose of the committee is to establish a Warning System Procedure that will be used across in a standardised fashion across municipalities. The committee will coordinate the implementation of flood warning systems in accordance with appropriate standards; promote communication of flood warning information to the affected communities; monitor and review the performance of flood forecasting and warning services. For Urban water businesses, planning tools are to be provided by state government to focus on adaptive climate change policy, this is to be done to address the uncertainty of hazard whilst maintaining water security for populations. AdaptWater is a recommended online risk and cost-benefit analysis tool to quantify and project probability of damage and failure of assets from existing and potential hazards. Local Government Council at high risk such as Port Phillip, Westernport, Yarra, Greater Dandenong and Wyndham, are recommended to revise and contact VICSES for comprehensive emergency response updates.

3. Infrastructure Management

Levee Management and Flood intelligence technology for decision making and defence are recommended as the first points of measures taken for flooding mitigation. Levee management is crucial for the protection of property, public and private infrastructural assets. 98% of Victoria’s rural levees are not formally maintained (Emergency Management Victoria, n.d.), this means that the protections against moderate to minor floods are not ensured. A more stringent routine of maintenance, structural upgrade and management needs to be implemented by

Catchment Management Authorities, DELWP and Local Councils. Urban levees need to be established along waterways and coastal areas in Port Phillip, Westernport, Yarra, Greater Dandenong and Wyndham. Although levees do not ensure complete safety from inundation, they create opportunity for the safe evacuation of population.

Flood intelligence technology allows for accurate information relating to actions to be taken in response to identified hazard consequences. VICSES is recommended to work with DELWP in ensuring that local councils are provided with sufficient flood information. The flood intelligence platform ‘FloodZoom’ ought to be advised to responsible authorities. State Victorian Government is recommended to establish three tier management teams to assist and support councils in the communication and development of comprehensive risk plans. These teams should be [1] State [2] Regional [3] Crisis Teams with delegated responsibilities and control centres for community resources and resupply arrangements.

4. Environmental Impact Statement

A Rapid Impact Assessment Matrix (RIAM) be developed by State Victorian Government and DELWP to implement structural flood mitigation measures in areas of high level risk (City of Port Phillip, Wyndham, Wavenport, Dandenong, Melbourne, Werribee, Yarra). The principal of the RIAM is to provide decision makers and responsible authorities viable sources of information to incorporate into planning processes and infrastructure projects. According the statutory requirements of the Local Government Act 1989, Melbourne Water Corporation Act 1992, Planning and Environment Act 1989; Advanced environmental impact interpretation based on the outputs of hydraulic, hydrological, sediment, water quality and ecological modelling studies is required. Detailed studies provided by DELWP including flora, fauna, cultural heritage, hydrology, landscaping, design and visual impact analysis, geotechnical and marine based investigations and social impact research, are to be referred to and assessed for each council area.