Looks like some sort of Iris....Blue Flag?

It's either Acorus calamus or Iris pseudacorus. Those ripples in the blade are the clincher, can't remember whether Wcorus had it ( or not). Acorus leaves would smell if crushed.

I think I'd go for Acorus calamus if pushed. Iris pseudacorus are already in bloom and tend to grow much more densely.

Acorus calamus has the waviness on the leaf, also a single prominent vein a little to one side of the middle of the blade. The spicy-sweet smell of the leaves is distinctive.