Texture Scrolling

Like conveyor or river, when implementing these kinds of elements, I would consider to rolling repeated texture. 

Here's the following steps: (no script)

1. Use UI Raw Image, so you can manipulate UV Rect Offset. 

2. Change texture Wrap Mode to Repeat. 

3. Add an Animation to the element and manipulate the offsets in timeline.
[In order to make infinite loop, the last key should look the same as the first key]