Technical Note on high-frequency, multi-elemental stream water monitoring: experiences, feedbacks, and suggestions from seven years of running three French field laboratories (Riverlabs)

Abstract. High-frequency and multi-elemental stream water monitoring are acknowledged as necessary to address data limitation in the fields of catchment sciences and freshwater biogeochemistry. In recent years, the development of stream bank analyzers and on-site field laboratories to measure various solutes and/or isotopes at sub-hourly measurement intervals is in progress at an increasing number of sites. This trend should likely persist in the future. Here, we share our experiences of running three French field laboratories (called Riverlabs) over seven years. This technical note gives an overview of the technical and organizational points that we identify as critical in order to provide guidelines for the successful implementation of future projects running such equipment. We therefore share the main stages in the deployment of this tool in the field, the difficulties we encountered and the procedures we used to identify and eliminate their causes. Some of the critical aspects discussed here relate to 1) Supply of the field laboratory: basic functioning of the pumping, filtration and analytical systems, 2) Data quality control and assurance via maintenance services and operations, 3) Data harmonization and coordination of the laboratory components, and 4) Team structure, skills and organization. Our two main conclusions for a successful, long-term functioning of these types of field laboratories are, first, the necessity to adapt several central components of the field laboratory to the local conditions (climate, section, topography, water turbidity, power) and, second, the need of diverse and in-depth technical skills within the engineering team. We believe that sharing these experiences, combined with providing some practical suggestions might be useful for colleagues, who are starting to deploy such or similar field laboratories. These considerations will save time, improve performance and ensure continuous field monitoring.