The paper outlines the integration of Environmental Risk Management in Goulburn- Murray Water with previous work on Dam Safety, Business and Occupational Health and Safety risks. This has now been followed by the development of an Environmental Management System (EMS) to provide an environmental risk management framework for the whole Authority.
An Environmental Audit in 1997 identified deficiencies in some areas of environmental management and questioned the Authority’s ability to demonstrate due diligence. This led to a decision to develop and implement an EMS based on the International Standard ISO 14001.
Examination of Goulburn-Murray Water activities, associated environmental aspects and impacts, (and the consequences arising), led to the establishment ofan environmental risk register. Analysis and assessment of the risks to produce a ranking Jrom low to very high is described. Refinement to a significant risk register (high and very high risks), and consolidation into a list of generic risks based on major activities, functions and asset categories is described.
Based on this risk profile for the Authority, the Environmental Policy and Objectives were revised, and a methodology for identifying Environmental Targets was developed. Environmental Risk reduction is then delivered through the implementation of target driven Environmental Management Programs (EMPs).
Major system elements described include an emergency response plan, a legal register, an authority / responsibility matrix, a document control system, procedures, forms, training, auditing, and reporting.
The paper describes some of the practical issues encountered and the lessons learned with a focus on the activities of the Headworks Business. A prospective view of implementation and culture change issues is given.
Peter Quinlan and Sergio Giudici
The Hydro Electric Corporation (HEC) owns and manages 54 large and referable dams across Tasmania. Monitoring, data storage and data utilisation techniques have evolved significantly over the years as the dams have aged and as instrumentation, communication and data management technologies have advanced. This paper describes the development of the HEC’s ‘Asset Safety Evaluation Tool’ (ASET) for acquisition, management and interpretation of data relating to dam safety management. The paper also provides examples of how ASET has been applied within the HEC to demonstrate how the primary functional development goals of robustness and practicality have been achieved.
Kumara Arachchi and Kelvin J Lambkin
Wetlands by their very nature act as storages of pollutants and nutrients in systems subject to environmental stresses. Wingecarribee Swamp acted in this manner and enhanced the quality of catchment runoff flowing into the Wingecarribee Reservoir until the structural failure of early August 1998 in which 6000 megalitres of peat and sedimentary material were moved into the Reservoir. Protection of the Swamp’s functions and values is directly related to Sydney Catchment Authority’s core objectives of protecting the environment and protecting public health by supplying drinking water of acceptable quality. Due to the catastrophic failure, water quality in the reservoir and the ecological integrity of the Swamp have been compromised. The incident has also resulted in significant dam safety issues.
This paper describes the dam safety, catchment management and water quality response to the failure of a major peatland which covered 8% of the catchment of Wingecarribee Reservoir in the Southern Highlands of New South Wales.
Michael Cawood, Roger Jones and Ken Durham
A methodology for local disaster management planning based on Australian/New Zealand Standard AS/NZS 4360:1995 — Risk Management has been developed as an out-working of a Flood Risk Study for Murweh Shire. The methodology has relevance to all local governments, particularly in view of National Disaster Relief Arrangements (NDRA) that now link the extent of NDRA funding available for a re-occurring natural disaster event to the existence of disaster mitigation actions or plans. This places a premium on actions being taken by local governments to mitigate public safety risk at community level.
Duane M. McClelland and David S. Bowles
There is a growing concern about the limitations of the approaches to life-loss estimation that are currently used in dam safety risk assessment. This paper summarises insights into factors that affect evacuation effectiveness, loss of life, and survival, based on a detailed review of historical dam breaks and other types of floods. The understanding and empirical characterisation of life loss dynamics being developed from these case histories are intended to provide the foundation for an improved practical life-loss estimation model.
Andrew Day, Rod Bridges and Corrado Fabbri
A joint venture between Astaldi SpA of Italy and Thiess Contractors Pty Ltd of Australia (ATJO) has just completed a 95m high roller compacted concrete (RCC) dam on the island of Sulawesi in Indonesia. The dam which includes 528,000m’ of RCC was completed in September 1999 and will provide hydro-electric power for a nearby nickel smelting operation.
One of the largest RCC dams built in the region in recent times, the construction presented a number of unique challenges in particular placing techniques to cope with the heavy rainfall in the area as well the logistics to this remote location. Other aspects which are addressed in the paper include production rates, RCC placing systems (Rotec), dam formwork systems, aggregate sources, RCC mixes and waterproofing (membrane).
After early problems with the river diversion, the works were accelerated and completed to a very tight program. To enable dam construction to commence prior to river diversion the wall was advanced as a series of separate monoliths which led to a number of RCC placing innovations.