For the usual reason ... to get to the other side. Presumably he or she happened to wander into town in the course of travelling to another wetland habitat, searching for new territory and/or a mate. This semi-aquatic rodent isn't really a rat, it's related to voles.
When I first saw this guy he was sitting near the stairs by the Municipal Office, but by the time I got home and returned with my camera he had retreated to the relative saftey of a nearby window well. I prefer my subjects in more a natural setting, but my camera, a Canon PowerShot A530, can't take pictures of animals at even a short distance, so I took the opportunity to acquire whatever photos I could of Ondatra zibethicus.
