If some glass plane blocks are were a source block would be created, a source block will be created there, causing the water to flow into other panes and flow through by itself.

To reproduce, create a 3x3 hole with the inside as so:
a=air
w=water
p=pane

waw
app
wpa

Water will flow into the center pane and though the others after, causing the air block in the bottom right to be filled with water.

Picture order: