Dual-extreme cumulative impacts and threats in agricultural catchments: The need for effective integrated policy

Farm dams in catchments create cumulative threats to downstream farmers, communities, and environments and if not managed individually, the problem will aggregate at the catchment level creating “dual-extreme cumulative impacts and threats”. The aim is to explore the concept of dual-extreme cumulative impacts and threats to downstream communities and environments arising from inappropriate on-farm water storage within the Australian setting: a setting comprising high inter-annual rainfall variation creating dual hydrologic extremes of floods and droughts. The problem is explored through comparative case studies undertaken with ground-based photographic interpretation providing supporting empirical evidence. We find farmers storing more water than they are entitled to, with downstream users and the environment potentially suffering and at threat because of unsafe dams. Results indicate a need for integrated safe and equitable farm dam management accountability and assurance policy, and its effective implementation. We add to existing international dam policy literature by introducing the dual-extreme concept and demonstrating the critical need for effective integrated policy. Guidance is provided for jurisdictions seeking improved farm dams management for sustainable and safe catchments.