Are banks and waterways now obsolete in Australia's cropping areas?

Anyone who has witnessed rill and sheet erosion on  a cultivated paddock knows the damage can be severe.  Topsoils have been lost in  a large variety of soil specific slope situations in just one rainfall event  A lot of effort was put into designing and using banks and waterways in the early days of Soil Conservation services in Australia- even on very low slopes.( original post here was on the Charlton area )
Minimum tillage and improved management of weeds and soil structure has greatly limited the need for such works in many areas,   but should certain slopes still have some specific design structures ?( not those red soils again?)

Banks and waterways don't automatically stop sheet and rill erosion and  many of the early banks and waterways in the Charlton area  probably created higher erosion risks because they prevented a  full acceptance of the poor land capability.  We have learnt to resist some of these works to focus more on capability assessment , rejecting risky land use practices  and maintaining soil structure.
That great move aside -Are there still places where banks and waterways can be considered?

• Contour buffer strips?  
• Are they still being built anywhere in Australia ?
• Banks protecting low slopes below steep high water shedding  hills?
• Where soil types and are easily eroded ? (eg where loam topsoils are still in place)
  
• Would high cereal prices push some farmers to use marginal lands again? 
• Have we properly factored in the adverse effects of certain types of terrain  on the actual rainfall events and therefore estimated return periods  in some hill country ?( see previous posts)