Freshwater modeling in Aotearoa New Zealand

Freshwater modeling is vital for addressing environmental and societal challenges. In two workshops preceding this article, we revealed issues in current modeling practices in New Zealand, with a focus on catchment-level water quality modelling. Predominant were low trust in models, lack of transparency, and models unfit for purpose. This article uses a root-cause analysis to explore these issues, identify causes, and propose solutions. We find that current best practices and research are a good foundation but insufficient to fulfill our freshwater research and management needs. We advocate for long-term national strategies with centralized funding, standardized documentation, data, models, evaluation techniques, and communication methods, along with a centralized open-access platform for collaboration. Our vision is to streamline modeling projects, enhance the accessibility and reliability of models, and foster more effective decision-making processes for the sustainable management of freshwater ecosystems.