Backdrop at Mason Park Bridge

[P5se Camelback]

You might give that a try ... it would enhance the appearance of light and shadow, but do so subtlely. You might also consider darkening the first tree on the left of the backdrop a bit to more closely resemble the saturated color of the 3-dimensional trees right at the backdrop, and then darkening the next tree also, although not quite as much.

As for the water ... the problem appears to be that the "water" on the horizontal plane, although a darkish color, reflects a considerable amount of light due to the gloss coating on its surface, much as real water does. The same does not happen on the vertical "water" on the backdrop.

Because of the two intersecting perpendicular planes, the chances of getting a reflection from the vertical plane to appear the same as the reflection off the horizontal plane is like hoping for snow in July. [You might have a chance if you live in Independence Pass, CO.]

I think that a possible solution, though it may be a daunting task, might be to attempt to mix a color similar to the color of the "reflected light" color of the water on the horizontal surface. (Try it on a piece of paper first.)