How does New Zealand compare to Australia?
Australia is one of the most arid countries in the world. Most irrigation occurs in the Murray Darling Basin. At one million square miles, the basin is four times the size of New Zealand (yet only 15% of Australia).
Alongside the issue of size, how Australians supply water for irrigation differs hugely from the New Zealand approach. Large-scale dams are commonplace. Rivers are then used to convey the water to the irrigator or irrigation scheme. In New Zealand the majority of irrigation takes come directly from rivers. We have limited stored water, most of which is stored on-farm in small, shallow ponds. One of the challenges for New Zealand is how we are to build large scale water storage infrastructure. As communities decide they want more water in the river during the summer for native fish, plants and recreation, river water takes for irrigation will become more unreliable ( as less water is available). Water storage will be essential as it will create benefits for all New Zealanders.
Another contrast is how we license water. In New Zealand, most irrigation operates under short term permit/consents (typically between 20 and 35 years). This provides limited security for farmers investing in irrigation as there is no guarantee that the permit/consent will be renewed. Australia, despite its scarcity of water, grants a license in perpetuity. This long-term right, combined with water trading, encourages water efficiency. Farmers not needing their water will trade it with those that do.