Progress of the Canterbury Water Management Strategy and some emerging issues

Abstract

This paper reviews the progress to date of the Canterbury Water Management Strategy and identifies key developments and emerging issues. The paper examines the provision of storage, water use efficiency, environmental flow adjustments, nutrients from land use intensification, biodiversity enhancements and kaitiakitanga. The collaborative process has led to some more sustainable changes. One is the use of off-river storage and tributary storage as alternatives to mainstem storage. A second is improved environmental flow regimes by increasing minimum flows and reducing allocations at low flows; but enabling access to allocations at higher flows and providing time to adjust to new requirements. The parallel achievement of reduced nitrate loads and increased irrigation areas is proving problematic. Water use efficiency is advancing on some fronts – piped distribution replacing canal distribution and ongoing conversions to spray irrigation – but not on others – soil moisture demand irrigation and reallocation of surface and groundwater use to enhance recharge. Biodiversity enhancements and incorporating kaitiakitanga in water management are showing positive progress. Some of the key emerging issues include the allocation of nitrate capacity between existing and new users, and, the need for increased capacity for predictive modelling and field measurement to improve management of the use of scarce water and the cumulative effects of its use.