First, the "water" received several coats of Modelmaster's Gloss varnish, then I glued the clumps of tall grass: I picked a small portion with a tweezers, cut with a sharp scissors, dipped one end in white-glue and placed on the "water", trimming the excess once everything dried.
The vegetation on the river bank is a mix of Heki grass (in the blue bottle cap), and dried tea leaves. I brushed a bit of water+dish washing soap+white glue where I wanted to place it, then used the big brush to pick some up and beated it off gently with the tootpick, blowing the excess off once everything was dried, again.
Finally, I airbrushed a really thin coat of Desert Yellow to blend everything and give it a dusty look (covering the water with tissue paper beforehand).
This is the end for this project, now onto painting the Flak 40, I guess.