The first reason to capture data is help ourselves better understand the situation in our own community and then "discover" new information by the analysis and display of data. Certainly GIS mapping is one of the great tools we can use. But, there ought to be more data that we can convert and display using maps.
Recently I was told a story of elected officials being briefed by their emergency management team and being very surprised about the risks facing their community. There are some who would say, "Shame on the emergency managers for that condition to exist." But, I think it is not that uncommon. Emergency management and disasters are not a high priority for most until there is an actual disaster. Today as I write this, the elected officials in Houston are finding out much more about the flood risk and drainage problems that exist in their community thanks to record rains and flooding.
It is data that tells the story. More data, better stories, more engagement and with open data, more opportunity for others to use what we have and perhaps in return help us improve our own programs.