Why would the movement of water through cell walls be considered the apoplast and symplast pathway? I understand why it's considered the apoplast pathway (as the water is moving through a non-living part by diffusion) but should it not be considered symplast since that is only for when water moves through living structures? Thanks in advance.
The apoplast is the space outside the plasma membrane consisting of intercellular spaces where the material diffuses freely; it includes parts such as the cell wall and intercellular spaces.
The symplast consists of the cytoplasmic network of plant cells interconnected by plasmodesmata.
I suppose, in the motion of the upper stream of water (as indicated by the blue arrow in the diagram) you can see that to enter the symplastic pathway, the water has to first pass through the apoplastic pathway, in a sense. That is, it cannot 'teleport' directly into the cell's protoplasm, it has to pass through the cell wall.
Hope that clears things up.