Jersey Shore? I drive by on i-80 during my daily commute
It is a nice town.
As a kid, I had a dog that enjoyed groundhog patrol. He was a 60-ish pound mix - german shepherd and husky. Groundhogs are tough, so I wouldn't turn a dog smaller than 50-ish pounds loose on one. Even that biggish dog may need a vet trip for stitches the first few times they tangle with a groundhog. They would probably just laugh at a cat.
I have multiple groundhogs at my current house. Putting up simple
chicken wire barriers around my
trees keeps them off. They are pretty lazy and will take the easiest meal. Unless there are mulberries involved - I have seen them climb trees for mulberries.
I also have a tendency to allow all kinds of delicious weeds to grow around my property, which they tend to eat instead of the stuff I want to eat. So far, they have let my hugels alone, so maybe something like a raise bed is a deterrent...