Aotearoa New Zealand is making significant investment in reducing nitrate discharges to water via national policy and standards such as the National Policy Statement for Freshwater Management (2020), regional plan rules, and ultimately on-farm actions, in response to pressures from the community to reduce the impact of intensive land use on groundwater quality and stream health.
The expected nitrate loss reduction associated with any given policy, plan rule, or on-farm action is typically estimated via modelling (e.g. Overseer) with significant uncertainty margins. Existing groundwater water quality monitoring systems are predominantly designed to provide a regional-scale indication of nitrate concentrations and long-term trends and are therefore not able to determine the effectiveness of nitrate loss mitigations within the desired timeframes (e.g. 5-10 years) and spatial resolution. This means that the effectiveness of implementing new nitrate management approaches may not be known for several decades (and sometimes much longer), and the needs of stakeholders, kaitiaki, communities, and regulators to track progress towards nitrate targets in receiving waters are not being met.
The Mitigation Effectiveness Monitoring Design programme is funded by Our Land and Water, which is part of the National Science Challenge, and seeks to tackle the mismatch between current monitoring network infrastructure and traditional monitoring network design approaches. It considers the requirements for successful mitigation effectiveness monitoring design by researching spatial and temporal water quality variance and developing interactive web tools and guidance for regulatory bodies, communities, and stakeholders.
The toolkit will inform users how to monitor specific freshwater attributes; when, where, how often and for how long, with what technology, and at what potential cost. This will be achieved by evaluating existing network performance, network improvement options and new network designs and facilitating a Te Ao Māori based approach. Case studies are an important part of the research.
KSL is leading the groundwater science part of the programme, investigating spatial and temporal variance in groundwater nitrate, and developing numerical and AI models to support the design of successful monitoring networks, improved freshwater quality outcomes, and better mitigation investment decisions. The work will be completed by the end of 2023.