I don’t necessarily know the right way to do this, but when i was creating a well object I filled the center with a water material and was playing with the existing materials in the ark resources. If you take a look at the lake water material, simply search “water” with the filter “material” on it will be toward the beginning of list. But if you open up this material to edit it and you go into the “Graph” tab you can see exactly how they make it go up and down in time. The function is called UV Displacement.