Maybe “Vanessa” is a Dem, or maybe “Vanessa” is a duck and therefore not expected to be particularly intelligent.
Other than the lack of water, though, that courtyard is a pretty good choice for a nest: No predators and relatively sheltered, and “Vanessa” seems to have solved the water access issue, so she can’t be that dumb. My guess is that if no one had ever helped her get to water, she’d have found a different nesting location next year.
Maybe it was a field or pond when she or her mother were hatched. Aren’t ducks, geese creatures of habit? — they will return to nest where they were hatched. Likewise for geese. And this may continue to happen over many generations.