classic waka stream

if the autumn leaves
had not flowed drifting along
the Tatsuta River—
who then would ever know
that autumn had reached its waters

Meaning
If the autumn leaves had not flowed along it, who would ever know that autumn had come to the waters of the Tatsuta River?
Commentary
Book Five Autumn Poems (Part Two)

Composed at the banks of the Tatsuta River.

Though the water itself shows little change through the seasons, the flowing autumn leaves reveal that autumn has come even to the river.
Author
Sakanoue no Koreyuki
Source
Kokin Wakashu
Other