The efforts of geologists who have modelled materials lying underneath the Heretaunga Plains have played a primary and integral role in better understanding water issues in Hawke's Bay, an expert has said.
GNS Science mapping geologist Dr John Begg gave a presentation at the recent water symposium to give those in attendance a better understanding of the distribution and function of underground gravel layers and fine grained materials.
Having mapped and modelled the Bay for three years as part of an urban geological mapping project, Dr Begg said geologists' role in water quality issues was to provide water experts with information about the materials that ground water resides in.
"We know the materials that stop the surface water mixing with those underground aquifers. So if we can outline the distribution of those materials under the ground then it provides the groundwater people with a fantastic skeleton that they can build their ground water models on," he said.
Dr Begg said a key element in the underground equation was the role of the fine grained materials (aquitards) which sit atop the gravel layers (groundwater aquifers) and essentially seal the gravels to prevent water escaping to the surface and surface water mixing with aquifer water.