Suspected illegal construction next door?

The lot next to me has their whole back lawn tore up and looks to be preparing to pour a foundation for a new building back there. They've got forms up and the plumbers were laying out plumbing yesterday.

Our drainage sucks on a good day, so how this would affect the drainage is a big concern. Does anyone know who to call to check to see if this construction is permitted or not? Thanks for your help.