1. Rock Fractures and Fluid Flow: Practical Problems -- 2. Physical Characteristics of Fractures and Fracture Patterns -- 3. Physical Properties and Fundamental Processes in Fractures -- 4. Fracture Detection Methods -- 5. Hydraulic and Tracer Testing of Fractured Rocks -- 6. Field-Scale Flow and Transport Models -- 7. Induced Changes to Fracture Systems -- 8. Case Histories -- 9. Technical Summary -- App. A. Committee's Statement of Task. Scientific understanding of fluid flow in rock fractures - a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storage - has grown significantly in the past 20 years. This volume presents a comprehensive report on the state of the field, with an interdisciplinary viewpoint, case studies of fracture sites, illustrations, conclusions, and research recommendations. The book addresses these questions: How can fractures that are significant hydraulic conductors be identified, located, and characterized? How do flow and transport occur in fracture systems? How can changes in fracture systems be predicted and controlled? The committee provides a geomechanical understanding of fracture formation, reviews methods for detecting subsurface fractures, and looks at the use of hydraulic and tracer tests to investigate fluid flow. The volume examines the state of conceptual and mathematical modeling and provides a useful framework for understanding the complexity of fracture changes that occur during fluid pumping and other engineering practices.