Canterbury Strategic Water Study
Canterbury consumes more water than any other part of New Zealand – 290 m3/s are allocated for abstraction from rivers and groundwater, and demand could double. Yet there is no strategic plan that integrates long-term development with the maintenance or enhancement of Canterbury’s water-environment values. That is likely to lead to environmental and economic problems.
The Canterbury Strategic Water Study was intended to identify long-term requirements, whether the needs could be met, and which resources were likely to be under stress. (The report is available from the Environment Canterbury website.) The study focused on water consumption, not hydropower generation, and on effects on instream flow. It assumed that existing standards for stream flows and environmental values would be maintained.
The greatest pressure on water allocated for abstraction is on the foothills rivers, such as the Waipara, Selwyn, and Ashburton. Although irrigation is the largest consumptive use, stock water puts the most pressure on many foothills rivers. Groundwater is significantly over-allocated in many areas; however, estimated use is less than the amount allocated, and the limit of sustainable groundwater use has probably not been reached in any area.
On a daily basis, Canterbury is short of water. Yet there is sufficient water throughout the year to meet foreseeable consumptive needs and instream flow requirements. To solve our daily problem we will have to store a significant amount of water, re-allocate some, and integrate our water management.
John Bright, Lincoln Environmental