Depth of Flow on the Downstream Side of the Bridge/Culvert

For abutments with a short setback (setback less than five times the hydraulic flow depth in the channel) or a negative setback use the hydraulic depth in the channel

For abutments with an medium or long setback, use the average depth of flow (hydraulic depth) in the overbank section between the channel and the abutment.

Please note that this information can be obtained from the ABSCOUR calculations.