The increasing availability of IoT sensors and off the shelf components creates opportunities for much more local business models, with entrepreneurs creating their own devices, infrastructure and services around IoT based sensing for hydrology. Nonetheless, most IoT-based sensing opportunities rely on sensors that were not originally designed for the purpose of hydrological observations. To move to much more local and affordable business around these sensors, we argue that 4 pillars are needed: free and open-source, use case oriented software; guidelines for hardware setups; documentation and a Community of Practice. We show the open-source OpenRiverCam framework for open-source image-based discharge monitoring as an example and derive lessons learned from several case studies with the framework.