Study tracks Wairarapa water

A six-year investigation into Wairarapa underground water resources has revealed "vital information" about the interaction between aquifers, rivers and streams and what happens when water is siphoned off for irrigation.
The investigation was launched by a department of Greater Wellington Regional Council, when worries arose over sustainability from year-on-year steady increases in water abstraction.
It has now concluded. The probe involved field studies and led to the development of a three-dimensional computer model that showed changes in groundwater and river levels after water had been abstracted.
As a result of the investigation a recommendation has been formulated urging that both ground and surface water - meaning rivers, streams, lakes and wetlands - should be managed as a single resource.
According to the regional council this would be a significant change as the existing regional freshwater plan - now up for review - has separate groundwater and surface water allocation limits.
A map showing colour-coded zones has been produced as part of the study.
The investigation concluded new groundwater management zones should be established throughout Wairarapa, with takes categorised by impact on the water flows and levels of neighbouring surface waters.
Typically shallow groundwater abstractions from areas close to rivers, streams and springs have more impact than deeper and more distant groundwater takes.
Environmental monitoring and investigations manager Ted Taylor said some of these closer bores obtain water by effectively "pulling it out of the river gravel".
Meetings have been held with water users to "advise of the direction we're taking", Mr Taylor said.
"The step now is to take that science work and turn it into policy work."
Should the recommendations become policy, in future less water would be allocated to those areas identified as being over-allocated, and more allocated to other areas.
Mr Taylor said the probe gave a strong scientific basis to underpin a review of existing water allocation policies in a new regional plan - due in 2013.