Meilhac, C.; Reeves, R.R.; Zemansky, G.M.; White, P.A.; Jebbour, N. 2009 Field investigation of groundwater-surface water interactions, Ruataniwha Plains. Lower Hutt, N.Z.: GNS Science. GNS Science report 2009/23127 p.
Abstract: Traditionally, management of water resources has focused on surface water or ground water as if they were separate entities. As development of land and water resources increases, it is apparent that development of either of these resources affects the quantity and quality of the other. Understanding groundwater-surface water interaction mechanisms are critical to successfully manage the water resources within catchments where there are high demands for water. The research described in this report was conducted to develop a better understanding of groundwater-surface water relationships in the vicinity of the Waipawa River in the Ruataniwha Plains of Hawke’s Bay, New Zealand. This programme of research was funded through the Crown Research Institute (CRI) Capability Fund (CF) that provides public funding to maintain, enhance, and foster current or new capabilities. This report summarizes the investigations and findings of a research programme developed by GNS Science (GNS) in collaboration with Hawke’s Bay Regional Council (HBRC). Specifically, this research was aimed at developing a better understanding of groundwater-surface water relationships in the vicinity of the Waipawa River to provide data for better modelling of this system and to improve the foundation for management of the water resources involved. Components of this research included: (1) assessment of stream-groundwater relationships using a more detailed potentiometric surface prepared from shallow groundwater elevation data, application of a heat tracer method to calculate streambed conductivity, and assessment of stream-groundwater relationships by differential gaging; (2) the application of surface geophysical methods to assess shallow aquifer properties and develop a relationship between geophysical results and hydraulic conductivity determined by aquifer testing; (3) the application of slug testing to determine hydraulic conductivity and comparison of slug test results with results from pump testing and geophysical surveys; and (4) the application of borehole geophysical methods (particularly, natural gamma logging) to assess aquifer lithology. (auth)