Since the late 1980's secondary soil salinisation has been recognised as a potentially threatening problem in many of the irrigated cotton growing areas. This has been most apparent in the lower Macquarie valley and at Bourke where large earthen storage dams constructed from semipermeable soil materials have leaked. Owing to the presence of subsurface textural boundariesshallow water tables have been created in adjacent irrigated fields which have redistributed stored soluble salts within the rootzone. In Dalby and the Lockyer valley, the application of poor quality irrigation water has resulted in minorproblems with salinisation of surface soil. Fortunately, there have been no widespread occurrences of secondary soil salinisation as a result of rising water tables or the prolonged use of poor quality irrigation waters.