If you have a wide water flow like what you are showing the most common method is to have them all flow over into a collecting trench that runs along the base of them effectively turning all the D's in the same row as the E into E's.
s - water source
f - flowing water
d - block
e - empty
The diagram unfortunately starts to get a little too complicated for me to do in ASCII, hehe. Basically the water flows from the sources to a trench that is one block lower so items fall into it, then the trench floats things down it. You generally use something like signs to make it so the water from above does not flow down into the trench as well.
The problem is, if the water in minecraft feels it should flow into a solid wall, it will, making dead zones in your flow where the current can not carry things. The latest flow I have had ended up using Corner source locations to get the water to all flow into a single hole at the center of a circle. Not sure if that design could work for you if you really need that single block area for flow reasons.