This is a textured construct. Here a "hill" morphed construct with a ground texture of 8192x8192 pixels, and with a hi-res plane (from the props folder) to "play" water. The background trees are painted on the "sky" texture in Blender.

If interested, I could make a video in the Poser2Blender2Poser series, (when my hand injury gets better) , because there are 2 ways to do this.

FireFly render with a single Infinite light.