Of course, poetry is all words and pictures in your mind... but my opinion is that young children will have trouble with this book simply because it uses words like "moreover," "anon," "laureate," "vocation," and many others that most adults would have to look up in a dictionary to fully understand.
One deliciously clever part of this book is that the text changes as the water flows over a waterfall. (You have to turn the book to read it, as the waterfall goes across the pages from left to right and the words are turned sideways to follow the flow!
If you're looking for a beautifully descriptive poem with lots of old English language, this is perfect. The illustrations are lovely and the poem itself is wonderful... but children may need quite a bit of explanation and assistance if they were to read or listen to this book.
As a teacher, I'd say a practical use might be to give sections of this poem to children (older grades) and have them practice their context clue and dictionary skills to figure out what the words mean.