Hi Dan.
Since I think you're likely to ask a more general idea, feel free to ping me on my email. I'm new to HXL, but I think that beyond some generic things (like try first use HXL-proxy instead or go too deep on the programming part, since HXL-proxy is faster if just want to process data, even if you know programming) I think that your cooperative is likely to at least consider some extra conventions on attributes to use, since the base hashtags are likely to not cover some subjects. I may not know these attributes, but since your team is starting something big, it makes sense to start to have at least some HXL examples focused on your use cases.
Also, one member of HXL-CPLP actually is very into the topic of water-related subjects in Brazil. On this topic, I think months later, Diego could change more specific ideas with your group.
Att.
Rocha