Pressure control can be an effective means of leakage reduction in some situations. This paper first presents the results of an experimental study to determine the appropriate equation to describe leak flow. In general, the orifice equation is most appropriate for situations when the dimensionless OS number (defined in the paper) is large, which is the case for most systems. This means that flow emitters are a good way to model leaks. The second part of the paper describes the application of computer modeling to a realistic system and shows how a model can be used to evaluate pressure settings and estimate the leak reduction and possible pressure problems. In general, pressure reduction is most attractive when leakage and pressure are both relatively high, flow is controlled by a PRV or variable speed pump, and the terrain is relatively flat. Time of day control or control valves of tanks may be needed to make pressure control work.