Jean, I like the way your version resolves the question of the waters overflowing. It reminds me of Spring runoff and the danger in the mountains of flashfloods -

    "I'd write it by the river where the waters o'erflow..."

And, it is always a fine balance between "making sense", "corruptions", and "its all pretty". I could never say that just because I may not be able to make sense out of something I don't enjoy hearing it or singing it. When you go back over all of the versions that have been posted here, there are many subtle changes and shades of meaning with just this one phrase. For instance, between your version and that posted by Richie, which says,

    "I would send it by the river where the waters overflow."

There is a difference between "writing by the river" and "sending it by the river". And as Michael has pointed out, in Mary Jane Queen's version, the waters "don't overflow". As I tried to read carefully back through this thread, I found this explanation from GUEST Terry McDonald, back on April 29, which is interesting:

"I've interpreted the version I know as fitting in very neatly with the emigrations from Wiltshire and Somerset to Upper Canada in the 1820s and 1830s. Many of these emigrants, whose passage was paid for by the parish were ex soldiers, and their letters home were published at the time in order to encourage other poor people to emigrate.

In 'my' version one of the verses is

'I wished I was a poet and could write a fine hand
I'd write my love a letter, so she'd understand
I'd send it by the islands, where the waters overflow,
And I'd think on Pretty Saro, wherever I go.'

Letters out of Upper Canada (like the emigrants who came in) would have been carried thought the St lawrence and through its rapids and the many islands between Quebec, Montreal and Kingston"

Terry, if you are still in touch, do you have specifically Canadian versions of this song? Can you say more?

But even here, it it is the waters rather than the islands that are overflowing. I'm still curious about islands overflowing. Even when a line gets changed, it then gets repeated over and over. I wonder what kind of images come to mind when you hear about "islands overflowing".