Further closing the integrated total water cycle in the Lockyer Valley: a catchment scale integrated water resource management conceptual model

Abstract

There is a need to facilitate decision making on integrated water resource management (IWRM) issues, minimise leakages from and further close the integrated total water cycle (ITWC). The complex social, economic and environmental dimensions and the scarcity of the resource make water management one of the truly “wicked” environmental management problems (cf. Rittel & Webber 1973). This study seeks to contribute to the resolution of this IWRM problem by adding a new definition of IWRM and providing analytical tools for the assessment of water catchments issues, conditions and improving management. A multidisciplinary integrated approach assisted in understanding and managing the complex dynamic multidimensional nature of water and its use. To advance this aim, a new conceptual model for catchment scale IWRM was developed then applied and refined, based on case studies. A review of literature reveals inconsistencies and complexities in the application of IWRM and approaches to minimising leakages from the ITWC. This study has developed an ITWC conceptual sub-model that demonstrates the capacity to incorporate the principles and theory of other disciplines such as hydrogeology, ecological economics and political science into the IWRM conceptual model. The new IWRM conceptual model determined the key components of IWRM using a case study of the Lockyer Valley in South East Queensland, Australia. Further international cases challenged and provided additional insights into these key components using the complex and interconnected dimensions of an IWRM conceptual model – environment, economic, social and policy. A mixed methodology combining quantitative and qualitative secondary data from the case study of the Lockyer Valley during the millennium drought (1997-2009) assisted development of a new catchment scale IWRM conceptual model and key IWRM components. The Lockyer Valley is a primary supplier of agricultural produce to eastern Australia, and contains the headwaters of the downstream Brisbane River catchment. The Lockyer Valley is primarily dependent on groundwater for irrigation, which it continues to draw upon in excess of its sustainable yield. Despite nearly 20 years of research and investigation into the Lockyer Valley and over 60 reports, research papers and consultancies, many of its IWRM issues remain unresolved. This case study was enhanced by a comparison with international cases of IWRM, which assisted in the developing and refining of a contemporary IWRM conceptual model, approach, definition and principles for worldwide application. This study advances water management using an IWRM conceptual approach that further closes the ITWC by focusing on urban-rural IWRM opportunities, going beyond using recycled water for irrigation. This model differs from previous models as it focuses on the ITWC rather than the natural water cycle. The limits of the environment are a feature of this approach, along with recognition of the role of social capital, policy input from government and non- government sectors, ecological economic theory and principles, and hydrogeological modelling for a catchment scale conceptual IWRM model, thus setting it apart from previous models in literature. These additions bring a wider perspective to IWRM decision making and assist in the management of ongoing issues of changes in climate, growing demand for irrigation water, population growth, environmental demand for water and excess wastewater. Such issues affect IWRM worldwide.