Can you be more specific? Do you want puddles, is it streaky, is the runway bumpy, are we going to be taking a picture of the image at the surface of the runway or a ways off? As a first shot given I'm not sure what we're doing just yet, I'd put two kinds of patterns in the color channel mixed with turbulence. One pattern would be asphalt, the other would be your water. Then I'd copy the same mixer into the reflection channel and mix different values until the "puddle" look was where you wanted it. This is just a first crack at it. Give us some more detail and we'll soak you! -Kix

-Kix