The management of the Central Valley Project in California is described. Organizational changes are analyzed and summarized. The management philosophy in the project's operations office is attuned to the complexities arising from technical and human involvement. Technical aspects of decision making are reviewed. The management of project operations is based upon organizational development theory. The paper illustrates that there is more to the successful implementation of contemporary management of river-basin operations than the design and use of mathematical models. The complete management system must account for the quality of the data and the goals and expertise of the people responsible for collecting and using the data. The development of modern river-basin management must be concerned with development of people as well as the creation of an efficient operating mechanism.