Carlino, AM & McCullough, CD 2019, 'Modelling the long-term water balance of a pit lake with recreational end uses', in AB Fourie & M Tibbett (eds), Proceedings of the 13th International Conference on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 1405-1420, https://doi.org/10.36487/ACG_rep/1915_110_Carlino
Pit lakes can be used for recreation when water quality is suitable. However, when lake levels are too low, pit lakes may pose access and slope instability risks to recreational users. An essential tool to assist in managing these risks is a good understanding of the lake water balance.
A groundwater model was developed to investigate whether impending cessation of mine water discharge into historic Lake Stockton (Collie, Western Australia) would result in reduced recreational values, e.g. for water skiing. Currently, the lake water level is kept reasonably constantly elevated with the addition of mine water from nearby dewatering at Ewington mine (Lanco, Griffin Coal) operations.
Lake Stockton has a maximum depth of 30 m and groundwater flows through historic underground mine workings contribute largely to the overall pit inflow. A steady state groundwater model was used to emulate the regional groundwater flow in the Collie Coal Basin. The model gave estimates of groundwater fluxes and predictions of the future lake water level if mine discharges were to stop.
Transient simulations forecast a 3.6–3.9 m decline in the long-term lake water level without mine water input, with non-mine groundwater inflow rates increasing from commensurately steeper hydraulic gradient from a declining lake level in steady state. As a result, although the water level of Lake Stockton would still be suitable for public recreation, the decline in the water level would expose steep pit walls and reduce the regulation recreational area by 17%. Consequently, rehabilitation planning for this lake should account for safe access if recreation is to be permitted when the predicted decline in water levels takes place.
The study highlights the critical importance of understanding the hydrogeological setting and the controls over lake levels in-pit voids for maintenance of recreational end use values.
Keywords: pit lake, recreation, water balance, numerical modelling
Anderson, MP, Hunt, RJ, Krohelski, JT & Chung, K 2002, ‘Using high hydraulic conductivity nodes to simulate seepage lakes’, Ground Water, vol. 40, pp. 117–122.
Anderson, MP & Woessner, WW 1992, Applied groundwater modeling: simulation of flow and advective transport, Academic Press, San Diego.
Balistrieri, LS, Tempel, R, Stillings, LL & Shevenell, LA 2006, ‘Modeling spatial and temporal variations in temperature and salinity during stratification and overturn in Dexter Pit Lake, Tuscarora, Nevada, USA’, Geochem, vol. 21, pp. 1184–1203
Castendyk, D, Eary, LE & Balistrieri, LS 2015, 'Modeling and management of pit lake water chemistry 1: Theory', Applied Geochemistry, vol. 57, pp. 267–288.
Castro, JM & Moore, JN 2000, 'Pit lakes: their characteristics and the potential for their remediation', Environmental Geology, vol. 39, pp. 254–260.
Cheng, X & Anderson, MP 1993, 'Numerical simulation of ground‐water interaction with lakes allowing for fluctuating lake levels', Ground Water, vol. 31, pp. 929–933.
Commander, DP, Mills, CH & Waterhouse, JD 1994, ‘Salinisation of mined out pits in Western Australia’, Proceedings of the XXIV Congress of the International Association of Hydrogeologists, International Association of Hydrogeologists, Adelaide,
Council, GW 1997, ‘Simulating lake-groundwater interaction with mudflow, 1997 Georgia Water Resources Conference, The University of Georgia, Athens, pp. 457–462.
Environmental Simulations Incorporated 2000, Groundwater Vistas, version 6, computer software, Environmental Simulations Incorporated, Leesport.
Fetter, CW 1994, Applied Hydrogeology, 3rd edn, University of Wisconsin, Oshkosh.
Government of Western Australia 1958, Navigable Waters Regulation 1958, pp. 622–632.
Hammond, G & Boyd, G 1988, ‘Dewatering at Western No. 7 Colliery’, Proceedings of the 3rd International Mine Water Congress, International Mine Water Association, Melbourne, pp. 733–741.
Hanna, TM, Elfadil, AA & Atkinson, LC 1994, ‘Use of an analytical solution for preliminary estimates of ground water inflow to a pit’, Mining Engineering, vol. 46, pp 149–152.
Hinwood, A, Heyworth, J, Tanner, H & McCullough, CD 2012, 'Recreational use of acidic pit lakes – human health considerations for post closure planning', Journal of Water Resource and Protection, vol. 4, pp. 1061–1070.
Hunt, RJ, Anderson, MP & Kelson, VA 1998, ‘Improving a complex finite difference ground water-flow model through the use of an analytic element screening model’, Ground Water, vol. 36, pp. 1011–1017.
Hunt, RJ, Haitjema, HM, Krohelski, JT & Feinstein, DT 2003, 'Simulating ground water-lake interactions: approaches and insights', Ground Water, vol. 41, pp. 227–237.
Le Blanc Smith, G 1993, ‘The geology and Permian coal resources of the Collie Basin, Western Australia’, Western Australian Geological Survey Report 38, p. 86.
Lee, TM 1996, ‘Hydrogeologic controls on the groundwater interactions with an acidic lake in karst terrain, Lake Barco, Florida’, Water Resources Research, vol. 32, pp. 831–844.
Luke, GJ, Burke, KL & O’Brien, TM 1987, ‘Evaporation data for Western Australia’, Resource Management Technical Report Department of Agriculture, Perth.
Lund, M, Bills, D, Keneally, T, Brown, S & Thompson, S 2000, ‘Bacterial strategies for increasing pH in acidic voids’, Final void water quality enhancement: Stage III, ACARP Project Number C8031 report, Perth, pp.169–222.
Lund, MA, McCullough, CD & Radhakrishnan, NK 2012, ‘The Collie Pit Lake District, Western Australia: an overview’, Proceedings of the International Mine Water Association Symposium, Mine Water and Environment Research Centre, Bunbury, pp. 287–294.
McCullough, CD, Hunt, D & Evans, LH 2009, ‘Sustainable development of open pit mines: creating beneficial end uses for pit lakes’, in D Castendyk & T Eary (eds), Mine Pit Lakes: Characteristics, Predictive Modeling, and Sustainability Society for Mining, Metallurgy, and Exploration (SME), Colorado.
McCullough, CD & Lund, MA 2006, ‘Opportunities for sustainable mining pit lakes in Australia’, Mine Water and the Environment, vol. 25, pp. 220–226.
McCullough, CD, Marchand, G & Unseld, J 2013, ‘Mine closure of pit lakes as terminal sinks: best available practice when options are limited?’, Mine Water and the Environment, vol. 32, pp. 302–313.
McCullough, CD, Müller, M, Eulitz, K & Lund, MA 2011, 'Modelling a pit lake district to plan for abstraction regime changes', AB Fourie, M Tibbett & A Beersing (eds), Proceedings of the Sixth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 581–592.
McCullough, CD, Schultze, M & Vandenberg, J 2018, ‘Realising beneficial end uses for pit lakes’, in C Drebenstedt, F von Bismarck, A Fourie & M Tibbett (eds), Proceedings of the 12th International Conference on Mine Closure, TU Bergakademie, Leipzig, pp. 497–504.
Merrit, ML & Konikow, LF 2000, Documentation of a Computer Program to Simulate Lake-aquifer Interaction Using the MODFLOW ground-water flow model and the MOC3D solute transport model, United States Geological Survey, Reston, p. 4167.
Moncrieff, JS 1993, ‘Hydrogeology of the Collie Basin, Western Australia’, Western Australia Geological Survey, pp. 129–153.
Müller, M, Eulitz, K, McCullough, CD & Lund, MA 2010, Mine Voids Management Strategy (V): Water Quality Modelling of Collie Basin Pit Lakes, Edith Cowan University, Perth, p. 105.
Niccoli, WL 2009, 'Hydrologic characteristics and classifications of pit lakes', in D Castendyk & T Eary (eds), Mine Pit Lakes: Characteristics, Predictive Modeling, and Sustainability, Society for Mining, Metallurgy, and Exploration, Colorado.
Schultze, M, Hemm, M, Geller, W & Benthaus, F-C 2013, 'Pit lakes in Germany: Hydrography, water chemistry and management', in W Geller; M Schultze; R L P Kleinmann & C Wolkersdorfer (eds), Acidic Pit Lakes - Legacies of surface mining on coal and metal ores, Springer, Berlin.
Stedman, C 1988, 100 Years of Collie Coal, Curtin Printing Services, Perth, p. 363.
Varma, S 2002, Hydrogeology and Groundwater Resources of the Collie Basin, Western Australia, Hydrogeological Record Series HG 5, by Water and Rivers Commission, Perth, p. 80.
Wilson, AC 1990, ‘Collie Basin’, Geology and Mineral Resources of Western Australia, Memoir 3, Geological Survey of Western Australia, Perth.
Zhang, Q, Varma, S, Bradley, J & Schaeffer, J 2007, Groundwater Model of the Collie Basin, Western Australia, Department of Water, Government of Western Australia, Perth, p. 106.