New Zealand, Hydrology in Question

For a region like Hawkes Bay, the fruit bowl of New Zealand, water is a vital economic driver, meaning that secure access to irrigation water and best quality management practices are essential.

This extends not just to the horticultural industry but also crops, vineyards and dairying. The Heretaunga Plains with its fertile alluvial soils and warm, dry climate is highly productive. There are many consented irrigation takes abstracting from both surface water i.e. directly streams and rivers and from groundwater stored in the underlying aquifers.

Recent work carried out by Hawke’s Bay Regional Council identified that the water resources are under increasing pressure from abstraction and measures are required to control and manage adverse environmental effects. These issues are the result of a high level of interaction between groundwater and rivers coupled with direct abstraction from rivers. Low river flows are impacting in-stream ecology and water quality is under pressure from increased sediment run-off and nitrate loading. The management approach adopted is to halt all new allocation from the aquifers, pending the outcome of a community lead Regional Resource Management Plan (RRMP) change. The plan change is known as TANK, a name derived from the four main river catchments (Tutaekuri, Ahuriri, Ngaruroro and Karamu). In addition to the plan change, an application for a Water Conservation Order (WCO) was made for the Ngaruroro River and this is also in process. The draft plan prepared by TANK for the management of the water resources in the Heretaunga Plains is due for release in the coming months and this will change the landscape in terms of water management and decision making for the region. It will be some time before the plan change is finalised and adopted, the details are as yet unclear, but one thing is certain and that is that change is on the way for the regions water.

The team of hydrologists and hydrogeologists at Lattey are assisting water permit consent holders to rationalise their existing consents to maximise benefits. Where appropriate we are seeking novel solutions to help consent holders adapt to the changing landscape of water consenting.

We have also directly challenged several Hawke’s Bay Regional Council low flow consent conditions and devised augmentation strategies.