350 wells surveyed for one-day groundwater snapshot
Around 350 Rakaia-Ashburton wells will be surveyed on August 26 as part of an ongoing Environment Canterbury programme to model and understand the groundwater system in mid Canterbury.
Environment Canterbury groundwater hydrologist Mike Thorley said the piezometric[†] survey will provide more information on the three-dimensional water flows in the aquifer system below the Rakaia-Ashburton Plains area.
“The survey is a huge logistical exercise as the wells need to be measured on the same day – Thursday 26 August – to provide consistent and useful information.
“This information will help the development and refinement of our groundwater model for the area, which is part of the ongoing scientific investigations work at Environment Canterbury.
“All available Environment Canterbury groundwater staff will be in the field measuring the water level inside the 350 or so wells, which were identified and checked earlier this year by two university students working on the project over the summer months.”
In addition staff from Environment Canterbury’s surface water section and NIWA will be measuring flows in the Rakaia and Ashburton rivers, which will provide additional information for the groundwater model.
“The survey of well pressure will give us a snap-shot of groundwater conditions and allow us to further develop our three-dimensional model of the water flows in the Rakaia-Ashburton aquifer system,” said Mike Thorley.
“Our aim is to understand how groundwater moves through Canterbury’s aquifers and the balance between groundwater and surface water, so Environment Canterbury can better manage the region’s freshwater resource.”
The survey is part of a two year water resource investigation across the Rakaia-Ashburton Plains area. The next field activity will be a follow-up well survey in late April or May 2011 at the end of the irrigation season which will provide information on the change in seasonal groundwater levels.
Every landowner with a well included in the project should have either received a letter, an email or been phoned by an Environment Canterbury staff member about the upcoming survey day.
The survey involves an Environment Canterbury staff member making a short visit to measure the groundwater level in each well. The measurements are not part of Environment Canterbury’s compliance activities and the data is for the scientific investigations programme only.
More information on Environment Canterbury’s groundwater model for mid Canterbury is available at:
http://ecan.govt.nz/advice/your-water/groundwater/3d-geological-model/Pages/Default.aspx