Different strategies in water management exist to deal with water scarcity issues in agriculture. This chapter provides an overview of the fundamentals and developments of two water allocation/demand management strategies, i.e. water sharing and water trading, with a focus on the Australian experience. Both water sharing and trading have been advocated worldwide for many decades. However, there is still a need today for ongoing debate, dialogue and improvements to the systems to both (a) increase adoption and implementation and (b) avoid potential adverse effects. Three major themes can be identified as a basis for successful water-allocation regimes, namely: (i) institutional/regulatory capacity; (ii) integration/stakeholder involvement; and (iii) monitoring/control systems. Considering future population growth and the projected water quantity and quality issues, functioning water sharing and water trading systems will need to be at the core of improving water management and delivering more resilient irrigation communities.