Jan van Schilfgaarde, USDA Agricultural Research Service and National Research Council Committee on Irrigation-Induced Water Quality Problems In 1982, a startling discovery was made. Many waterbirds in Kesterson National Wildlife Refuge were dying or suffering reproductive failure. Located in the San Joaquin Valley (Valley) of California, the Kesterson Reservoir (Kesterson) was used to store agricultural drainage water and it was soon determined that the probable cause of the damage to wildlife was high concen trations of selenium, derived from the water and water organisms in the reservoir. This discovery drastically changed numerous aspects of water management in California, and especially affected irrigated agriculture. In fact, the repercussions spilled over to much of the Western United States. For a century, water development for irrigation has been a religiously pursued means for economic development of the West. The primary objective of the Reclamation Act of 1902 was, purportedly, the development ofirrigation water to support family farms which, in turn, would enhance the regional economy (Worster, 1985).

As the world population increases, there is increasing competition for waterquantity as well as quality. Provided here is an up-to-date perspective on Available Water Resources (Part I), Water Conservation and Technology inAgricultural Systems (Part II), Problem Water Uses and Treatment (Part III),and Management and Policy Evaluation (Part IV). The book is an invaluable source of information for water resource planners, managers and policy makers, researchers and students, and irrigationists.

This work presents models that characterize the relationships between quantity and quality of irrigation water application, and agricultural production and the environment. A comprehensive modeling approach addressing both the benefits of irrigation and the potential negative effects is introduced. Physical-biological concepts are combined with economic and engineering principles to demonstrate the usefulness of the model for analyzing various water management and policy issues. Decision makers on all levels should find the modeling approach interesting and useful in the management issues from the farm to national levels.

This volume brings together a number of prominent economic studies all of which deal with key water quality issues. The studies focus on the economic aspects of water quality including identifying the polluters' actions and incentives, designing and comparing control mechanisms, analyzing the costs and benefits of water quality programmes, and finally managing transboundary water quality. They all make recommendations for improving water quality through changing incentives, programmes and/or policies.

Water is often seen as a free commodity. However, this is rarely the case as demand for water is increasing significantly across the world. This book focuses on the key roles of irrigaiton and drainage in the debate on water. Irrigation is a major player in the demand for water and already accounts for between 70-80% of the total world consumption.

Centralized, top-down management of water resources through regulations has created unnecessary economic burdens upon users. More flexible decentralized controls through the use of economic incentives have gained acceptance over the past decade. The theme of this book is the increasing efforts throughout water-scarce regions to rely upon economic incentives and decentralized mechanisms for efficient water management and allocation. The book begins with a section of introductory chapters describing water systems, institutions, constraints, and similarities in the following regions: Israel and the Middle East, Turkey, California, Florida, and Australia. Four of these regions face similar climates with wet winters and dry summers. Florida has a more even seasonal distribution of rainfall, yet it uses similar management strategies in controlling groundwater demand and water quality. The book concludes with a section on water management case studies. These case studies examine issues of conflict related to both water quality and water quantity. While the case studies address both international and intranational concerns in specific regions of the world, they portray broad principles that are applicable to many regions.

In December 2002, a group of specialists on water resources from the United States and Iran met in Tunis, Tunisia, for an interacademy workshop on water resources management, conservation, and recycling. This was the fourth interacademy workshop on a variety of topics held in 2002, the first year of such workshops. Tunis was selected as the location for the workshop because the Tunisian experience in addressing water conservation issues was of interest to the participants from both the United States and Iran. This report includes the agenda for the workshop, all of the papers that were presented, and the list of site visits.