Municipalities never propose projects just to take advantage of opportunities, but they certainly do to meet pressing and glaring needs among their residents. That is the case for all the projects I have seen. None of them could be considered hare-brained; all are essential projects that will upgrade the current infrastructure and, in some cases, develop infrastructure that does not currently exist, which is needed and that the municipality might not have been in a position to build with its own financial resources.
Those are the two most frequent cases.