Managing water in rural towns: a water balance approach

[Truncated abstract] The clearing of native vegetation for agriculture in the Wheatbelt region of southwestern Australia has significantly impacted on runoff and recharge and contributed to the creation of serious environmental problems such as salinity, soil degradation and water logging as a result of rising water tables. Salinity and waterlogging are causing substantial damage to rural town infrastructure as many townsites are located in lower valleys where the problems are most pronounced. With the view to addressing these environmental problems and developing new locally-based water resources for such water-limited environments, a holistic approach has been adopted to manage water in the rural townsites. This water balance management approach includes the conjunctive use of surface water, groundwater and urban sourced water. In line with this holistic approach, the objective of this study is to gain a better understanding of the hydrological and water management processes in a rural townsite by capturing and evaluating hydrological processes and water management options from a total water balance perspective using a conceptual water balance model developed as part of this research. This methodology is built upon the use of available datasets and information collated for rural towns located in the dryland agricultural areas of southwest Western Australia. The Rural Town Water Balance Model (RTWBM) is a nondistributed multiple bucket model representing the various water stores of an 'idealized' rural townsite, which is organized in the model in terms of both landuse and surface types. Rainfall, imported "scheme" water and fringe area inflows are the main inputs to the model, all of which are then partitioned and routed through various components of the model; this leaves the surface water system components as evaporation, surface runoff and recharge to groundwater. The calibrated RTWBM was used to investigate the impact of climate variability and landsc