Ashley-Waimakariri river water study

Ashley-Waimakariri groundwater and surface-water study

Environment Canterbury has begun a major study of the water resource in the plains area between the Ashley and Waimakariri rivers, north of Christchurch .

Regional Council hydrogeologist John Weeber says the study aims to better understand the water balance. It will examine the amount of water entering the system from rainfall and runoff, the amount of water used for irrigation, as well as water exiting the system via rivers and streams, evaporation, and groundwater flows.

“The study will provide valuable information on the interaction between groundwater and spring-fed streams in the area. It will also help to better understand the effects of water takes, to improve the reliability of water supplies, as well as helping to avoid adverse effects on spring-fed streams,” says John Weeber.

Two students have been employed by Environment Canterbury to work over the summer months on a pilot project to gather initial information and develop methods and procedures, ahead of the full study in 2010 and 2011.

Postgraduate Geology student Adam Smith is reviewing the Environment Canterbury well database as well as visiting wells in the area to confirm their location and check their suitability for the study.

Adam Smith, who will begin a Masters degree in Engineering Geology next year, says his studies this year included work on Canterbury groundwater.

“I have completed projects on the isotopes present in Canterbury groundwater, which help identify the age and source of groundwater. I really enjoy the complexity of the groundwater system and am looking forward to working on this water investigations study,” says Adam.

John Weeber says some wells in the area are already monitored by Environment Canterbury but additional wells are needed to build a better understanding of the interaction between ground and surface-water.

“If people think they may have a well that will provide good information please contact us and let us know the details.”

Another key aspect of the study is gathering information on flow-rates from consented takes in the area.

Penny Slade, a second year science student at the University of Canterbury , is helping to check and gather the surface-water field information. She will also work next summer to help process and analyse the flow data as part of the full study.

The full study will include a survey of the water level in wells in early winter (after the irrigation season) and again during the 2010/2011 summer irrigation season.

“The results of this major study will enable Environment Canterbury to better manage water in the Ashley-Waimakariri area, as well as helping to ensure better environmental outcomes,” says John Weeber.

“It will help build our understanding of where water comes from, what happens to water in the area between the two rivers, and where it goes.”

Note: All water consent holders in the Ashley-Waimakariri plains area will be contacted as part of the study.

Land-owners will be notified prior to Adam, Penny or other Environment Canterbury staff visiting their properties.

ENDS