Hi, David, you might find the articles at figure modeler/painters' Alan and Marion Ball's website, on a diorama they did, depicting the climactic fight in "The Last of the Mohicans" as illustrated by NC Wyeth. It's a 2-part SBS, available in pdf at this URL:
www.mb-miniatures.com/.../artikel.php
It may be of interest, because Marion modeled the waterfall that appears in the background in the painting. The technique might be something you could use to depict sprays of water.
My own thought would be to start with a piece of stretched clear sprue, or a piece of optical fiber, as a "backbone" for the arc of the spray, and then to use products like Woodland Scenics to create the spray itself, flowing from the arc.
In what scale are you building?