Modelling complex environmental and water use Objectives for integrated resource management

Integrated water resource management often warrants total picture of the catchments and understanding of how various components of the nature interact with each other. Resource managers need a detailed, yet practical, modelling tool that can assist to prepare appropriate management plan. This paper demonstrates a robust water resource planning model with its ability to provide result which was useful in formulating a water sharing plan. The integrated water quantity and quality model (IQQM) is a planning tool that is used to investigate impacts of water resource management options in the river system with or without dams. IQQM computes major processes in a river system such as reservoir operation, resource assessment and accounting, international water sharing, irrigation and town water demands, water quality and environmental requirements. The formulation of the water sharing plan of the Lachlan River Valley of eastern Australia has been used as an example. The Valley is about 85000 km2 and has two reservoirs with a total capacity of 1250 million m3. Robust modelling is essential to investigate the impacts of proposed water resource management plan which may include irrigation, water supply, environmental targets and wetlands. This paper discusses integrated modelling of environmental objectives like transparent or translucent dam, restoring natural flow frequency, wetland inundation pattern and assessment of dynamic impact on irrigation reliability to meet the flow rules. The brief examples of the role of planning model in feasibility studies of water development projects are discussed.