Tall grass, I know it is not grass.Long stalk and like grass on the top. Near our library in White Rock
It will either be moved indoors or allowed to die and be replaced annually. That's common in commercial settings. If by chance there is (pond) water and it's heated the root mass could easily survive and resprout in Spring.
Cyperus papyrus is a perfect resemblance. I would look what happens to that plant in winter. I am sure it was here last summer
Leaves and stalks more flattened than those of C. papyrus. Especially that flowering section at the front, with ribbon-like leaves included - and somewhat different flowering habit from C. papyrus. With about 600 species in the genus there is no need for it to be an extra familiar one like C. papyrus.