Here are two samples with the full range of Solid Bitmaps 10 through 90, plus a solid black polygon. The first is Sue's first suggestion and the second adds her second tip.

Edge Fade, Inner - Edge Width 2.5, Inner Opacity 80, Outer Opacity 25

Edge Fade, Inner - Edge Width 2.5, Inner Opacity 80, Outer Opacity 25 plus Glow Radius bumped to 0.5

I think bumping the Glow radius to 0.5 is nice. And these are working nicely, so I don't think I will try importing other water fills to see if any of them work. I'm leaning towards Solid 90 because for my poor eyes at least, I really have to zoom in on the pure solid one to see the stonework behind the water.

Thank you for your help, Sue! Looking forward to plotting out my main city's sanitation system over the next few weeks. Sewers make for such great adventure options -- emergency exits when you're being besieged, or for plotting out heists. I imagine a lot of crime lords dump a lot of evidence (and bodies) in the sewers...

Hmmm, I'm not seeing much of a difference, but there's some glare on my screen at the moment. Here they are:

First Edge Fade off, second one on

First Edge Fade on, second one off

Both Edge Fades off

And here's the FCW file:

On today's Live demo, which was about Sinister Sewers, I asked for recommendations for what to use as a fill style for pure water uncontaminated with sewage (such as water runoff from storm drains). I had been using Effluent 05, but on another Water sheet with a transparency effect. Sue recommended trying one of the Bitmap Solid fill styles.

Here's a practice attempt, with the five effluent fills above and then five on the solid bitmaps below (from Solid 10 Bitmap through Solid 50). The five below are on a Water 2 sheet in case anyone recommends effects different than the regular Water sheet. Right now, I put the same effects on Water 2.

I am leaning towards Solid 40 Bitmap for storm drain runoff (since that water will have dirt and other impurities), and maybe something like Solid 20 Bitmap for pure water (for example, if dwarves are using this technology for a subterranean aqueduct).

Thoughts? (If this is too difficult to see here, I can post it in my Gallery if that has a better resolution.)

The clouds (or smoke?) are great! Are they from a symbol set or did you use a different technique?

Realized I didn't have any stains or scum, so added a bit. Really love how this template includes so many different effects options for adjusting the coloring.