Transfer Pathways Programme (TPP) : New research to determine pathway-specific contaminant transfers from the land to water bodies

Abstract

Land use (source) can only be defensibly linked to an effect on a receiving water body (receptor) if the critical transfer pathways and the hydrological and biogeochemical processes that occur along them are understood. Depending on the natural setting of the catchment and the contaminant concerned, surface runoff, interflow, artificial drainage, shallow and deep groundwater may be critical pathways. The Transfer Pathways Programme, which was successful in the MBIE 2015 investment round, has therefore been developed to quantify pathway-specific transfers of nitrogen (N) and phosphorus (P) that take lag times and attenuation potentials of the different pathways into account. The multi-disciplinary research team will be working closely with industry (DairyNZ) and council partners (Waikato Regional Council, Environment Canterbury, Marlborough District Council), as well as iwi on achieving the programme‟s aims.By 2018 we will have established how N and P transfer is partitioned across the pathways relevant in four case study areas (Wairau Aquifer, Ashley-Waimakariri, Hauraki, Upper Waikato). A catchment typology scheme will facilitate the application of transfer pathway understanding in other, less well studied catchments. Concurrently, we will apply an iterative modelling framework to integrate existing data of different types and quality, identify knowledge gaps, characterise and quantify fluxes, analyse uncertainty, and ultimately derive simplified models for management purposes. The quantitative understanding of the contaminant transfers through the various pathways together with the tools developed will enable stakeholders in land and water management to develop fit for purpose policies, management practices and mitigation measures. The research will thus help to maximise economic benefits from land use while achieving the water quality targets mandated by the community.