This publication provides introductory technical guidance for civil engineers, mechanical engineers, electrical engineers and other professional engineers, construction managers and electric power system managers interested in hydroelectric power systems. Here is what is discussed: 1. COMPUTER SIMULATION OF POWER POTENTIAL, 2. POWER PLANT SIZING, 3. POWER OPERATIONS, 4. POWER PLANT STRUCTURES, 5. GENERATOR VOLTAGE, STATION SERVICE AND CONTROLS, 6. HIGH VOLTAGE SYSTEMS, 7. GENERATORS, 8. TURBINES, 9. OIL, COMPRESSED AIR, PLUMBING AND FIRE PROTECTION SYSTEMS, 10. WATER SUPPLY, UNWATERING AND DRAINAGE, 11. PUMPED STORAGE.