This is master record for 3D hydrogeological models used to describe and model behaviour of NZ groundwater systems

NitrateWatch project (SSIF Project 6) is gathering nitrate data from around New Zealand. Our goal is to provide this information visually to our stakeholders via a map interface • NitrateWatch is aimed at generating new knowledge about nitrates in rural drinking water across New Zealand. • We aim to highlight nitrate hot spots and benchmark nitrate levels for rural drinking water by collecting data from drinking water samples submitted by rural residents. • A further goal is to improve stakeholder engagement through working more closely with iwi, Regional Councils, district Councils, Government agencies and local communities in readiness for future cooperation. • Data generated from this project serves as a talking point to showcase GNS’ leadership in the groundwater/drinking water space. • Our data provides future opportunities for GNS groundwater staff to build new projects leveraged off NitrateWatch

This is master record for NZ hydrogeological models used to describe and model behaviour of NZ groundwater systems

Groundwater boreholes are represented by point data with each point having attributes describing location, depth and water levels, if known. Additional attribution characterising aquifer type has been added to the original data for the purposes of this project. The data layer is part of the 'Geology of the Middlemarch area' 1:50 000 dataset covering a part of of East Otago around Middlemarch township.

This data set provides an update of New Zealand’s depth to hydrogeological basement map. Depth to hydrogeological basement can be loosely defined as the ‘base of aquifers’; or more strictly as ‘the depth to where primary porosity and permeability of geological material is low enough such that flued volumes and flow rates can be considered negligible’. For more detail on the process and methods, see Westerhoff et al. (2019). New Zealand groundwater atlas: depth to hydrogeological basement. Lower Hutt (NZ): GNS Science. 19 p. Consultancy Report 2019/140. DOI: https://doi.org/10.21420/FQXD-VY44 Cite data as: GNS Science. (2019). Depth to hydrogeological basement [Data set]. GNS Science, Ministry for the Environment. https://doi.org/10.21420/FQXD-VY44 Cite report describing the data as: Westerhoff et al. (2019). New Zealand groundwater atlas: depth to hydrogeological basement. Lower Hutt (NZ): GNS Science. 19 p. Consultancy Report 2019/140.

This dataset is a model-derived steady-state mean water table at the New Zealand nationwide scale with a resolution of 250m x 250m. These data are described in Westerhoff et al. (2018) – URL: https://hess.copernicus.org/articles/22/6449/2018/ . The model used aimed for a solution that obtains a nationwide overview of groundwater that bridges the gap between the (too-)expensive advanced local models and the (too-)simple global-scale models. The model is inspired by an existing, global-scale, groundwater flow model and improved by feeding in national input data of New Zealand terrain, geology, and recharge, and by slight adjustment of model parametrisation and model testing. The resulting nationwide maps of hydraulic head and water table depths show that the model points out the main alluvial aquifers with fine spatial detail. DOI: https://doi.org/10.21420/KZ52-NT28 Cite Dataset as: GNS Science. (2018). National water table model [Dataset]. GNS Science. https://doi.org/10.21420/KZ52-NT28

The LIMS Water Dating Lab Information System contains sample submission information for tritium, CFC, SF6, radon, stable isotope, and C14 samples submitted to the Water Dating Lab. The LIMS records data on sample processes and pretreatment. Once the results have been checked and pass QC then these results are uploaded to the LIMS masterlist. The database creates results reports as the user requests. The results are reported by email to commercial clients. invoicing is independent of the database, however invoice numbers are recorded in the database for reference. The Water Dating Lab manages the digital databases, paper records and physical remains of submitted materials.

Hawkes Bay Regional Council commissioned SkyTEM Australia to collect SkyTEM data for 3D aquifer mapping. In February 2020, 1235 km of SkyTEM data were collected over the Poukawa and Otane Basins. Data processing was carried out by GNS Science to remove electromagnetic noise. The retained data was used to develop both smooth and sharp resistivity models for the area. The standard depth of investigation varies from 60 to 490 m for the smooth resistivity model. External Quality Control was provided by Aarhus University HydroGeophysics Group. The data is owned by Hawkes Bay regional council. Cite as: Rawlinson, Z.J.; Westerhoff, R.S.; Kellett, R.L.; Pederson, J.B.; Maurya, J.B.; Foged, N. 2021 Hawke’s Bay 3D Aquifer Mapping Project: Poukawa and Otane Basin SkyTEM data processing and resistivity models. GNS Science consultancy report 2020/138. 76 p. [June 2021]

Hawkes Bay Regional Council commissioned SkyTEM Australia to collect SkyTEM data for 3D aquifer mapping. In January/February 2020, 2610 km of SkyTEM data were collected over the Heretaunga Plains, including four offshore lines. Data processing was carried out by GNS Science to remove electromagnetic noise. The retained data was used to develop both smooth and sharp resistivity models for the area. The standard depth of investigation varies from 12 to 650 m for the onshore smooth resistivity model and from 20 to 72 m for the offshore smooth resistivity model. External Quality Control was provided by Aarhus University HydroGeophysics Group. The data is owned by Hawkes Bay regional council. A series of 3D models were developed using the same horizontal regular grid as the existing Heretaunga numerical groundwater model (that will be revised in a subsequent piece of work). The 3D models utilise 100 x 100 m grid cells horizontally and 2-m-thick grid cells vertically. The primary objective was to provide detailed 3D models and hydrogeological interpretations suitable to be utilised by subsequent numerical modelling and online visualisation tools. 3D model datasets were created and saved in an accessible .csv format, with x,y,z defining the centre of each grid cell. This format enables rapid model visualisation in an interactive online webmap and as 3D block models within a Leapfrog viewer file Cite as: Rawlinson ZJ, Foged N, Westerhoff RS, Kellett RL. 2021. Hawke’s Bay 3D Aquifer Mapping Project: Heretaunga Plains SkyTEM data processing and resistivity models. Wairakei (NZ): GNS Science. 90 p. Consultancy Report 2021/93. (Final report on processing and resistivity modelling) Rawlinson ZJ. 2023. Hawke’s Bay 3D Aquifer Mapping Project: 3D hydrogeological models from SkyTEM data in the Heretaunga Plains. Wairakei (NZ): GNS Science. 69 p. Consultancy Report 2023/57 (3D Hydrogeological modelling)

Hawkes Bay Regional Council commissioned SkyTEM Australia to collect SkyTEM data for 3D aquifer mapping. In January/February 2020, 3941 km of SkyTEM data were collected over the Ruataniwha Plains. Data processing was carried out by GNS Science to remove electromagnetic noise. The retained data was used to develop both smooth and sharp resistivity models for the area. The standard depth of investigation varies from 20 to 640 m for the smooth resistivity model. External Quality Control was provided by Aarhus University HydroGeophysics Group. The data is owned by Hawkes Bay regional council. A series of 3D models were developed with 100 x 100 m grid cells horizontally and 2 m thick grid cells vertically. The primary objective was to provide detailed 3D models and hydrogeological interpretations suitable to be utilised by subsequent numerical modelling and online visualisation tools. 3D model datasets were created and saved in an accessible .csv format, with x,y,z defining the centre of each grid cell. This format enables rapid model visualisation in an interactive online webmap and as 3D block models within a Leapfrog viewer file. Cite as: Rawlinson ZJ, Reeves RR, Westerhoff RS, Foged N, Pederson JB, Kellett RL. 2022. Hawke’s Bay 3D Aquifer Mapping Project: Ruataniwha Plains SkyTEM data processing and resistivity models. Wairakei (NZ): GNS Science. 79 p. Consultancy Report 2022/38. (Acquisition and resistivity modelling) Rawlinson ZJ. 2024. Hawke’s Bay 3D Aquifer Mapping Project: 3D hydrogeological models from SkyTEM data in the Ruataniwha Plains. Lower Hutt (NZ): GNS Science. 60 p. Consultancy Report 2023/117 (3D Hydrogeological modelling)