River-related ceremony readings

How about this - by TS Eliot (you could even be cheeky and change "Thames" for "River" or the name of another river...
There, in a meadow, by the river’s side,
A flock of nymphs I chanced to espy,All lovely daughters of the flood thereby,With goodly greenish locks, all loose untied,As each had been a bride;And each one had a little wicker basket,Made of fine twigs, entrailed curiously,In which they gathered flowers to fill their flasket,And with fine fingers cropt full featouslyThe tender stalks on high.Of every sort, which in that meadow grew,They gathered some; the violet pallid blue,The little daisy, that at evening closes,The virgin lily, and the primrose true,With store of vermeil roses,To deck their bridegrooms’ posiesAgainst the bridal day, which was not longweet Thames, run softly, till I end my song.