Artificial Supplementation of Six River Pools in the Collie Basin, Western Australia

摘要

The supplementation requirements of six environmentally and socially significant river pools of the Collie River South Branch within the Collie Basin in Western Australia have been calculated using the water balance method. Groundwater levels in the area of the pools are depressed and are below the bed levels of most of pools due to large-scale groundwater abstraction in the basin for coal mining and power generation purposes. The affected pools will require artificial supplementation to maintain their environmental and social values. The purpose of the study is to calculate the volumes of water required to maintain water levels in pools. These volumes of water for different pool levels have been determined by calculating leakage and evaporation from pools at these levels. Estimation of hydraulic conductance of the pool bed material, for calculation of leakage from the pools and groundwater inflow, has been carried out using a simple water balance method. An aggregate of 2.3 ML/day will be required to maintain the pools at their cease-to-flow levels. However, if the pool levels decline, supplementation at higher rates will be required to initially fill the pools. Nomographs for estimation of discharge rates for different filling periods of the pools have been presented.