Our team has extensive experience throughout Australia and overseas; a summary of which is provided below. ERSA also works closely with a number of Associates; senior practitioners in the field of disaster risk and NRM.


Mikila Rosewall is Chair and a Director of ERSA. She has a Masters in Environmental Technology from Imperial College, London, and is based in Melbourne.

Mikila has worked as an environmental consultant and advisor for 15 years in the fields of environmental and natural resource management, natural hazard and climate change risk assessment, environmental impact assessment and program evaluation. Mikila is an experienced project manager.

Mikila has worked with Ken Granger (ERSA’s Principal Risk Scientist) on a number of natural hazard risk assessments and is adept at GIS and spatial mapping. Most recently this has included a scoping risk study for the NSW Ministry of Police and Emergency Services, and a multi-hazard disaster risk assessment for four Queensland local governments.

Mikila has extensive and diverse environmental management experience including climate change assessment and mitigation. She has led a number of climate change related projects including a study on the impacts and management implications of climate change for Australia’s projected areas; and an assessment of the risks of climate change to key ecological assets in northern Australia.

Mikila has a detailed knowledge of the regional delivery model for NRM, frequently consulting to the NSW Natural Resources Commission, and working directly with CMAs in developing their strategic plans. Along with her ERSA colleagues, Mikila has participated in six NSW CMA performance audits, and worked with a further two CMAs helping them to prepare for audits. Mikila has undertaken numerous NRM program evaluations for local, state and federal government agencies including the National Water Commission and the Murray Darling Basin Commission.

Mikila adds value to ERSA teams through her diverse experience, and her attention to detail.  She is a strong report writer and adept at tailoring reports to the audience.

Tony Batten is a Director and Company Secretary of ERSA. Tony has more than twenty years experience in managing and delivering studies and projects and is highly skilled in land management issues. He has formal qualifications in surveying and spatial information and has managed risk management and NRM audit projects, for a broad range of clients, in Australia, NZ, PNG, China and Vanuatu.

Tony’s work has included some projects that have led developments in risk science and NRM audit. For the NSW NRC, Tony led ERSA (and IID) teams in undertaking seven performance audits of the implementation of Catchment Action Plans (strategic regional NRM plans also known as CAPs). He participated in the development of the NRC’s audit methodology and Audit Manual and was Lead Auditor for two initial audits that were used to develop the audit methodology. For government agencies in Queensland, Tony has project managed a major Digital Cadastre Upgrade Project with Noosa Shire Council, as well as a large number of risk assessments. These include the Pine Rivers, Maroochy, Caloundra, Beaudesert and North Stradbroke Island Bushfire Risk Management studies and the Balonne, Beaudesert, Logan, Caloundra, Caboolture and Townsville Natural Disaster Risk Management studies, many of which have been robustly tested and proven accurate by recent natural disasters.

Tony also has experience in larger scale projects in some pretty challenging places. In 2001, he led a multidisciplinary UN team in China to design a $12 million Land Reclamation and Consolidation for Sustainable Land Use Project. This project established a policy framework for Chinese agencies responsible for the consolidation of rural farmland and the reclamation of land damaged by coal seam mining.

Tony has gained significant experience in business administration and corporate governance over the last twenty years, including serving as Director and Chairman of innovative land information start-up companies. His professional expertise has been recognised with an Australian Spatial Information Industry Business Association ASIIBA Chairman’s award for services to the spatial information industry.

These skills and experiences mean that Tony is often called on to provide project management and direction for ERSA teams. While he adds his extensive expertise and judgement to key project tasks, Tony also makes sure that projects are delivered on time and with minimal disruption to our clients’ day-to-day businesses.

Ken Granger is ERSA’s principal risk scientist. Ken has been directly involved in the study and analysis of natural and anthropogenic hazards and the risks they pose to Queensland communities for the past thirty years. Over that time, Ken has undertaken both single and multi-hazard disaster risk studies at local government and regional levels that cover some 78% of Queensland’s population.

Ken’s experience is built on an earlier career in the national security environment including significant studies on strategic military geography of northern Australia and work on Australian Defence Force plans to support civil authorities in PNG to plan for potential volcanic eruptions at Rabaul and Karkar Island.

Since 2001 Ken has ‘commercialised’ and further refined the risk assessment tools and techniques he has developed throughout his career, and applied them as a science.

Ken has undertaken projects planning for and analysing responses to the risks of most things nature can throw at us. He has undertaken, and/or led, some twenty emergency risk management studies in Queensland, NSW (Newcastle and Lake Macquarie Cities), South Australia (Port Adelaide) and New Zealand (Otago Region). He has also undertaken independent research for local government clients including the first major study of heatwave risks in South-East Queensland. He has undertaken a review of the recommendations of the 2009 Victorian Bushfire Royal Commission and their relevance to the management of bushfires in Brisbane City and a review of the degree to which Brisbane City Council’s CityPlan 2000 complied with the provisions of State Planning Policy 1/03.

Ken adds immense value to all ERSA teams working on risk-related projects, through his thought-leadership and unmatched professional judgement.  In addition to undertaking key project tasks in any disaster risk analysis, Ken also provides clients with a very broad context for their issues and the ‘next step’ thoughts that could further improve their risk and business practices.

John Leake has more than twenty years’ experience in agriculture and natural resource management (NRM) in most states of Australia and overseas. He is well-recognised for his knowledge in this field and has applied it through both a risk science and an NRM audit context.

John has considered NRM from the paddock to beyond the regional scale. While he has conducted field inspections of CMA-funded projects for NSW NRM audits, he has also led a mid-term review of the $32 million National Dry Land Salinity Program for Land Water Australia, spanning work in all states of Australia involving federal institutions, state authorities and local government, and a review of the $75 million Upper South East Dry Land Salinity and Flood Management Plan, for the South Australian Government.

John has taken part in projects looking at most NRM issues, including wetland design, management of dry-land grazing pressure, reuse of saline effluent water, and rehabilitation of degraded land and landscapes.

John’s work has contributed to the development of risk science and NRM audit approaches. As a key member of the ERSA (and IID) teams undertaking audits for the NSW NRC, John worked on the development of field sampling and assessment methods that are now accepted practice. On the risk side, in 2010, John worked with other ERSA team members to apply the ERSA risk science approach to analysing the impact of recovery efforts following the disaster caused by Tropical Cyclone Nargis in Myanmar. This work has led to significant interest in the role of natural resources in disaster risk management. He has also written and published papers on a range of NRM subjects including NRM audit and carbon sequestration into forests and soils.

John also works in some diverse and interesting environments, which allow him a unique breadth in the judgement he brings to ERSA projects. These jobs have included leading teams in planning and evaluating the US$1.5 billion Central Asian Initiative for Land Management (CACILM) for the five countries, and a range of ten donors including the Asian Development Bank, the World Bank, several UN group agencies, the German, Swiss and Canadian Governments and CGIAR agencies. In addition to his work in Myanmar, John has also worked in a number of other South East Asian countries.

John is an Adjunct Associate Professor at the University of Adelaide, Faculty of Social Sciences, School of Anthropology. He also sat on the NRM Council of South Australia, with responsibilities particularly focussed on water issues, and is a member of the State Water Information Management Committee.

John’s wide NRM knowledge and experience adds value to risk- and audit-focussed ERSA project teams. His ability to get alongside natural resource managers and understand their work from a very broad context often provides clients with valuable unexpected insights that help them improve their management and perspective of achievements.


Dr Marion Leiba has a PhD from University of Hawaii. She has worked in Australia, New Zealand and Trinidad, West Indies variously as a Volcanologist, Earthquake Seismologist and Landslide Scientist, including 20 years at Geoscience Australia. There she collaborated in multihazard risk assessments, including a pioneering quantitative landslide risk assessment of Cairns. She has had extensive experience in Science communication to the media, emergency services personnel, students and the general public. She currently updates the Australian Landslide Database on contract to Geoscience Australia. She also consults as a Disaster Risk Scientist, collaborating in natural hazard risk assessments for various local governments, and specialising in earthquakes and landslides.

Flo Bridger is a policy adviser with extensive experience in developing and implementing disaster risk management planning, policy and legislation. She has held senior roles in the Queensland Government, making major contributions in all hazards, pandemic influenza, cyclone, fire, tsunami and counter-terrorism planning and policy. She previously practised for eight years as a solicitor in the private and public sectors.

Flo has worked at local, state, national and international levels. She developed the Queensland Disaster Management Act, and the Emergency Management Act for the government of Tonga, and has advised on disaster management policy and legislation for the governments of Fiji, Papua New Guinea, Nepal and the Maldives. She served on the Council of Australian Governments National Working Group on Pandemic Influenza and the Australian Tsunami Working Group. In her public sector career, Flo also played key roles in liaison with and advice to Aboriginal and Torres Strait Islander councils and other organisations on disaster risk management, land use agreements and economic development.

Warren Bridson ESM is one of the most experienced front line disaster managers in Australia having worked in various positions within the Queensland disaster management sector for more than 30 years. He has had first hand experience of managing the impact of severe tropical cyclones and floods at the local, regional and state level. In 2010-11, for example, as Executive Director Operations within Emergency Management Queensland he led the response to the major flooding of Brisbane and the impact of severe tropical cyclone Yasi, two of the most significant disaster impacts in recent Australian history.

He has worked extensively across Queensland and has led disaster management projects in five Pacific Island Countries (Tonga, Kiribati, Vanuatu, Palau and Fiji) as well as undertaking studies in the USA. He established his own consultancy on his retirement from the Queensland Government service and has undertaken several projects focused on disaster planning and training. Most recently he was contracted as Training Coordinator for the Asia Disaster Preparedness Center project in Saudi Arabia to train humanitarian aid response teams for the Saudi Red Crescent Authority.

Warren was awarded the Emergency Services Medal in 2009 for his services to disaster management in Australia.

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