The book guidess readers in systematization, calculation, and design hydraulic impulse turbines, specifically Pelton and crossflow turbines, using algorithms that generate computer programs capable of providing a range of viable results within the limitations of currently available market technology. The turbines discussed in this volume have diverse applications—the Pelton can be used in micro-power plants as well as  large-scale power plants applications, and crossflow turbines are used mainly in smaller projects—and operate under   conditions ranging from  relatively high heads to s medium to low heads. The authors explore why impulse turbines are less commonly used in certain parts of the world  compared to reaction turbines, like the Francis and Kaplan turbines, that have been more widely employed, additionally they discuss how impulse turbines can be  particularly suitable for regions that have rugged topographies.