Research into Ruataniwha Water Quantity

Hawke's Bay Regional Council science staff will be carrying out hydrological monitoring of streams and rivers on the Ruataniwha Plains each month throughout 2009, the first in a number of such surveys to be conducted across the region this year.

“Increasing pressures on ground water, rivers and streams over the Ruataniwha Plains is leading the need to better understand water balance dynamics in this area. A year long study will help to improve our knowledge of this water system,” said Rob Christie, Principal Scientist.

The Council’s study aims to gather more information on the quantity of available plains water. It will help fill knowledge gaps that at present hinder decisions on sustainable water allocation through the catchment.

“Ultimately, by filling gaps in our knowledge on sustainable water allocation, results from this survey should provide more certainty to existing water users and better direction for new consent applications,” said Rob.

From 20-21 January, Council staff will start to gauge the flows in rivers and streams throughout the catchment each month.

This research will, however, require water consent holders to turn off pumps that are within 400m of the waterway, but still allows for water to be taken for stock and household use.

“Shutting off irrigation is a big ask especially when irrigation is critical during the dry summer months. Council staff will make use of irrigation bans where possible to conduct the required research and avoid additional strain on irrigators. Bans for this research will not be implemented if consent holders have already been warned of an impending ban due to low flow conditions” added Rob.

The Council has sent a letter to some 70 consent holders to inform them of the research and to request a 24 hour shut off to achieve one reading each month during 2009.. An irrigation ban for research can be requested by Council as a condition of most consents in the area.

A draft schedule of the research days has also been provided to consent holders. The programme will be subject to rainfall in the catchment, and the Regional Council has asked consent holders to provide their text, email, phone or fax numbers so Council can send cancellation alerts. Some compliance surveillance will be carried out, as any irrigation during the study will affect results.

Five teams will gauge 35 river and stream sites each month to measure the flow at a point in time starting 12 hours after the commencement of the irrigation ban.