Serious question, but how does a town/municipality handle network maintenance? Many of these stories seem to feature a lot of grants, and one-time costs but I

Serious question, but how does a town/municipality handle network maintenance? Many of these stories seem to feature a lot of grants, and one-time costs but I don't see much about the cost required to upgrade the network over time. I'm assuming some of the fee users pay is earmarked for this?