Groundwater nitrate nitrogen levels in Canterbury, New Zealand have been gradually increasing. A project was carried out from 2016 to 2019 to seasonally monitor 51 randomly selected wells of varying depths between the Ashburton and Rakaia rivers. The objective was to identify the variability in nitrate nitrogen levels in groundwater and to see how concentrations vary seasonally, sub-regionally, by depth and over time. This area is primarily farmland built on gravelly alluvial plains overlaying tertiary sediments of braided river deposits and greywacke. The project was initiated by farmers wanting to engage with the process of better understanding trends in water quality in their region. The sampling was carried out by the Foundation for Arable Research working closely with hydrologists to ensure protocols and procedures were consistent and valid. Recharge of aquifers further from the rivers and coast is achieved through a combination of rainfall, irrigation, snow melt and infiltration from rivers. Piezometric contours running between the two rivers illustrate that water movement is from the foothills to the coast, with groundwater levels becoming shallower approaching the coast. The sampling found there to be no differences in nitrate levels from north to south but concentrations increased as groundwater moved down the catchment accumulating as it moved towards the coast. Four wells were consistently over the maximum acceptable level for safe drinking water of 11.3mg NO3-N/L but the majority of wells had acceptable levels of nitrate nitrogen over the duration of the project. The information has enabled farmers to develop a better understanding of the high and low risk zones in the area. Importantly the participatory approach involving researchers and farmers has enabled the farmers to engage with regulatory bodies in constructive dialogue to develop outcomes that meet the environmental, economic and social needs of farmers and the community.