Vox has an informative article with some visuals on the goal of social distancing in an epidemic. If you can reduce the total number of infections that is a bonus, but the primary goal is to reduce the peak number of infections happening at any one time. You can do this by delaying cases and spreading them out of time, so that the capacity of the health care system is better able to deal with them. This looks very similar to a stormwater or flood control engineer – often, our goal is also to reduce and delay the peak. Reducing the volume is a bonus if you can manage it. The lesson is not that epidemics are like hydrology, it’s that there are certain fundamental system structures that lead to fundamental behaviors, and they are shared between systems. A couple more that come to mind along the lines of this basic model are congestion pricing to spread traffic out over time, and batteries to store solar and wind energy and trickle them back over time.