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Nitrates1

Canterbury’s groundwater nitrate level triggers plan change

A scientific investigation into potential groundwater movements under the Waimakariri River predicts a long-term increase in the level of nitrates in deep groundwater in Belfast and north Christchurch.

In July 2017 Environment Canterbury started an investigation which involved drilling nine new wells alongside the Waimakariri River to measure groundwater levels, water quality sampling; a piezometric survey across the zone to better understand groundwater flows; and sophisticated modelling.

The investigation found that it is likely nitrate levels in deep groundwater in the area around Belfast and north Christchurch will increase if current land uses persist.  The source of the nitrates is thought to be farming and intensive land use north of the Waimakariri River.

The results of the investigation were discussed with the Waimakariri water management zone committee at a briefing. The committee will use the information from the investigation to develop a set of recommendations and solutions for land and water management in the Waimakariri water management zone, in 2018.

These recommendations will be used by Environment Canterbury to set both water quality and water allocation limits for the Waimakariri water management zone, through a plan change to the Canterbury Land & Water Regional Plan.

Image credit: USGS