How to Make a River

Pre-wash your long swaths of fabric, even if they are PFD (Prepared for Dyeing). There is still a lot of goop to get off of PFD fabric. I used 2 12-yard lengths and 2 18-yard lengths.
Prepare your dye. I used Setacolor, and used about 1 part dye to 5 or 6 parts water for this first wash. (Then about 1:1 for the accent colors.)

Using gloves, dip each section of the cloth into the dye. Dip a section, then pull it out of the dye, wrap undyed fabric around it and squeeze to get the excess dye into the undyed fabric. Having white patches is OK.

Lay out the fabric. Natural wrinkling will occur. Since Setacolor is photosensitive, the wrinkles will be lighter in color than where the fabric is flat. This makes for great water! I chose to lay the fabric in the shade so that the contrasts would be subtle (also I have a shady yard!)

Add bits of complimentary colors. My base color was Turquoise. I brushed on bits of Emerald and Cobalt with a 4 inch paintbrush. Pushing hard on the brush made interesting variations from the grass and rocks underneath the fabric.

Finally, sprinkle salt onto the wet fabric. This is a great addition to give it a watery look.

I added fish while the fabric was still wet. They looked AMAZING for the first 15 minutes, then began to bleed. What I Learned: Add fish after the fabric is dry.