Suffolk County Water Bar construction notes
The above link is one of the best set of construction instructions I've ever seen, it even gives when this method is appropriate and where the diverted water
should go next.
Most of this type of water diverting should be designed to fit the terrain you have. Just like swales, there are places they just don't work like they are supposed to work so you have to do something different to not make the problem worse than it is already.
Slopes over 10 degrees are a good example, my drive has a 38.6 degree slope with a drainage ditch on the up hill side, I have installed coffer dams to catch the subsoil that does erode in the drainage so it doesn't all end up down at the valley, covering the road surface.
My south facing slope is still in the process of being terraced into planting sized platforms with the back side of each acting like a swale to soak in all the water they can hold.
Our path ways use water bars to divert water from them to grassy swales along the top of our ridgeline, this water used to take top soil away but now the top soil is stable and only the water moves slowly to our
berms on the down slope.