As you may have noticed, I'm in but actually out (being a NWDA-member). But for anyone wanting to pick up some ideas, here goes....
I decided to pick the flooded road photo as reference. First I took the basic road leveler from my Mountainside Road Pack, but in this case a normally warped simple shape line would have done for the road. The warp seed was hit a few times until I had a nice curve ahead. The soft perlin terrain was stretched a bit, so the road would go across a series of heights and dips, and a flood could go through one of the dips, perpendicular to the road. I hit seed of the perlin a few times until I had a decent dip right in front of me, kind of like in the photo. Then I added another soft edged simple shape of about 30m, used that to deepen the flood area. The road simple shape was used as a basis for a tarmac and lines. Usually I add a color adjust shader between road and terrain shaders to adjust the hardness of the road edges.
An inverted color adjust shader (coming from the road simple shape) was used to blend the surface shader containing a stack of grassy colors and small displacements. Next in line is the road surface shader, blended by the color adjust shader coming from the simple road shape. I wanted to raise the roadsides across the stream a bit so I added a distance shader, which blends a surface shader, in which I displaced the inverted road by 60cm.
I also want to make the road a bit curved up in the middle, so I added a transform shader from the main road simple shape, decrease its X to 0.6 and fed that into a displacement shader (0.2m) in the road line.
For the distance some higher (wooded) hills were needed, so I added another distance shader, plus another perlin, hit seeds a few times and there were some nice hills further across the stream.
Basics done, so then I needed a mask for the front roadsides (grass, herbs). So from the soft road shape I added a color adjust shader, set the gamma to 0.15, the black point to 0.8, and added that and the initial road shape to a merge shader, subtracting the hardened color adjsut shader from the soft normal shape, voila, roadsides. I could thus play a little with the values and get the grasses cover slightly more or less of the road.
Then the water. This is a plane, not a lake, so I can adjust its length/width more easily. Basically I start with a water shader, with a brownish murky color as volume 1 density 0.5, and some small scale waves, and a raised patchiness with decreased size. I then wanted some curly waves kind of perpendicular to the stream, so I took a perlin fractal with decreased whiteness, stretched 3x in Z, hit seed a few times until I had a decent distribution of white stripes across the stream. With an added transform shader I could manouvre them in place. Used that to add to the function input of a displacement shader after the water shader. I then added another perlin (wave) fractal, blended by a 3x X-stretched perlin for some 'disturbance' in the flow direction of the stream. Used the internal displacement and decreased the color so some foam appeared on the tops.
The curly waves needed some foam as well, so I added a foam pattern fractal (you can use warped small scale ridges, or a set of warped voronoi blue nodes), blended by the first Z-stretched waves, but also added a transform shader (X translate 0.25m) to move the foam a little off the tops and into the 'curls' I am anticipating. For the curls next in line I added a twist and shear shader, gave the X a lean factor of 2.
Next I wanted some foam where the water flowed onto the road right in front of you. So another foam fractal was used as a blender for a surface shader (white color, displacement offset 0.01). The fractal was blended in turn by a distance shader, so the foam would go a few meters, and not cover the whole stream.
Now the foam is white and not reflective, because the reflectiveness sits in the first in line water shader, so I could have added another reflective (RT) shader, but actually I didn't. I could also elaborate on the foam, which I didn't. Setting the surface shader that provides the white color to 0.5 or so, to make the foam more 'transparent' for instance, or adding tiny fake stones as 'bubbles'.... I didn't.
By the way; I made the road very wet near the water (reflective shader, reflectiveness 2 and a distance shader, blended by an enlarged soft river shape), and overall reflectiveness at 0.5. I first made the mistake to make the road wet by Ray Traced reflectiveness, but that took so long to render that I broke it of.
A line of trees next to the road: used the same warped road shape, moved it X wise a few meters and hardened it using a color adjust shader. I also used this to make some sort of upheaval next to the road. If you want to do this properly you transform the basic lines before they are warped, by the way. And a distribution shader was used to place some copses of trees on top of the further hills.
It had to look rainy, so I made a soft fairly covered sky (two layers), and raised the light exposure in the camera to 1.4 (or it would be very dark). I also added a low very soft misty layer.
And of course I had to make the sign.
This render is a halfway iteration, next to come later.