Legislative Council Fifty-Third Parliament, Second Session (53-2) 53 2 Parliament of South Australia Legislative Council published Question Time SA Water SA Water The Hon. D.W. RIDGWAY Legislative Council Leader of the Opposition SA Water The Hon. D.W. RIDGWAY (Leader of the Opposition) (14:33): The minister talked about the Bay of Biscay soils. What impact do temperature changes on soil and water pressure have on the rate of bursts? The Hon. I.K. HUNTER Legislative Council Minister for Sustainability, Environment and Conservation, Minister for Water and the River Murray, Minister for Climate Change SA Water The Hon. I.K. HUNTER (Minister for Sustainability, Environment and Conservation, Minister for Water and the River Murray, Minister for Climate Change) (14:33): I am not quite sure what he means by soil temperature or water temperature or atmospheric temperature, or whether he means, in fact, the requirements of the water in the pipe or the external operating situation with the soil and the chemical composition. They are all very important. We know we have those expansive clay soils because if any of us has ever lived in a house or rental accommodation in the eastern suburbs, we know that when it rains, usually after the season break on ANZAC Day, we get cracks in our houses. That will continue for two or three months. We have peaks and troughs in the amount of bursts and they usually align themselves with when we get rain and that expansive clay expands and causes cracking, and then it will settle down until we start to dry out again, around October, November and December, and then the clay of course contracts and it causes more soil movement. That exact same pressure that applies to houses is also applied to our pipes.