Mine Water and Environment Research Centre, Edith Cowan University
Faculty of Computing, Health and Science
School of Natural Sciences / Centre for Ecosystem Management
Open-cut mining can create pit lakes that form distinct lake districts. Localised factors at the lake level ensure that individual pit lakes develop different water qualities and ecological values. The Collie Lake District is formed from open cut coal mining operations in the south-west of Western Australia. The limnology and water quality of 13 of these lakes were investigated in 2009. All of the deep pit lakes appeared to be thermally stratified over the summer but many had, or were close to, mixing by autumn. The lakes were mainly Al buffered, with pH ranging from 2.5 to 6.4. Most lakes could be considered oligotrophic but some contained high N and moderate P concentrations. Dissovled organic C and metal concentrations were generally very low.