Traditional Ecological Knowledge ('TEK') in water has survived millennia, yet this knowledge remains poorly understood and utilised in Australia's water planning and management. Recent nation-wide water reform recognises Indigenous interests in water; it also confirms the importance of providing for 'environmental water' in water plans. This article proposes that there are significant, untapped interactions between these two policy developments: namely, that TEK can play a role in the determination of environmental outcomes in water planning. This is significant for Queensland, where traditional Indigenous values in water are to be provided for 'by ensuring there are sufficient environmental flows'. By reference to Queensland's Water Act 2000 and the Water Resource (Mitchell) Plan 2007 (Qld), this article addresses how Indigenous values are currently (un)represented in the determination of environmental flows. The article concludes by suggesting solutions for overcoming cultural and institutional barriers to the incorporation of old knowledge in freshwater management. Despite these barriers, Queensland is currently well-positioned to move towards genuine collaborative water planning and management with Indigenous communities.