Some may question the inclusion of this work of art in this community, because it wasn't made by using, depicting, or replicating any natural processes - but it was made to be affected by many natural processes, over time.
In this way the work is a clock of sorts - it marks the point in time where the water is at a certain level - the work is only 100% viewable at that time. Because of this the work can change multiple times a year as the water level fluctuates.
But this isn't the only way that the environment plays a part in not only how you see the artwork, but whether you see it. Because this artwork is situated within a natural environment, it's subject to the same natural processes of sediment deposition, erosion, and the general movements of water as anything else in that environment. This is intentional, and part of the installation of this work.
Though it may seem counter-intuitive to include this piece of art, to me it embodies the very ideology of natural process art in a way that few other works have done. It has been hugely influential and inspirational to me throughout my life.
https://en.wikipedia.org/wiki/Spiral_Jetty