Over the last half century, humans have become the dominant force driving many of Earth's cycles. Intensive agriculture and urbanization have simultaneously increased nutrient loading of pastoral landscapes and decreased the capacity of these ecosystems to retain or remove excess nutrients. Widespread degradation of terrestrial and aquatic ecosystems has triggered the establishment of ecological observatories, including the Zone Atelier Armorique (ZAAr) in western France, a part of the International Long-Term Ecological Research network (ILTER). The ZAAr includes a patchwork of land covers and uses, including primary growth forests, intensively cultivated row crops, and ancient bocage fields surrounded by hedgerows. In addition to traditional ecological research at ZAAr, which integrated pedology, hydrology, geochemistry, and hydrogeology, the last 8 years have seen the development of multi-proxy and multi-scale approaches to address surface and groundwater quality. Here, we present a global analysis of this 8 year dataset, including biodiversity, vegetation, soil water storage, and stream and groundwater chemistry. Our results highlight a clear relationship between land use and surface water quality, while groundwater quality appeared largely unrelated to land use, suggesting strong differences in nitrogen removal rates. We observed differences among dry and wet years in nutrient fluxes, with multi-year memory effects apparent for some parameters. Given such complex interactions, including emergent dynamics and decadal to centennial time lags, we conclude that multidimensional observations such as those supported by the ZAAr and other ILTER sites, are critical to understanding socioecological systems in the Anthropocene.