6 Aug 2010

Water scheme first to be tested by new system

7:17 pm on 6 August 2010

A large-scale irrigation project will be the first to be tested by a new modelling system designed to help manage and protect Canterbury's groundwater.

The model will help the Canterbury Regional Council decide where more water can be extracted and which parts of the aquifers are already under too much pressure.

The council says the model replicates what is happening underground - showing how pumping is affecting spring flows, how water gets into the aquifer, how it is stored, and for how long.

Groundwater hydrologist Mike Thorley says the model will initially be used to help determine the impact the Central Plains Water Scheme will have on groundwater.

The scheme plans to extract water from the Rakaia and Waimakariri rivers to irrigate up to 60,000 hectares of farmland.

Mr Thorley says the model will ensure there is enough groundwater for farmers' irrigation needs and the environment.

Greens challenge benefit of irrigation canal

The Green Party is challenging the view that an irrigation canal will bring environmental benefits to Canterbury.

A canal stretching from the north to the south of the region link existing and future irrigation schemes and water storage facilities is one of the ideas being considered as part of the Canterbury water management strategy.

Irrigation New Zealand says that would make economic as well as environmental sense.

It says among the environmental benefits would be the ability to ease pressure on the use of ground water reserves, by allowing some irrigators who rely on underground aquifers to tap into water stored from the winter snow melt instead.

However, Greens co-leader Russel Norman says if the canal concept allows an even greater expansion of intensive farming in Canterbury that is going to increase the contamination of water resources.