A neat solution to a nasty problem - he uses absorbent polymer beads and a measured does of salt to make a lightweight sand bag that absorbs floodwaters. The salt makes the bags more dense than the surrounding floodwaters so they stay in place. The flood water itself provides the mass as the beads expand.
When finished let them dry out in the sun and store for reuse.
Moderator, Treatment Free Beekeepers group on Facebook.