In 1997, New York City adopted a mammoth watershed agreement to protect its drinking water and avoid filtration of its large upstate surface water supply. Shortly thereafter, the NRC began an analysis of the agreement's scientific validity. The resulting book finds New York City's watershed agreement to be a good template for proactive watershed management that, if properly implemented, will maintain high water quality. However, it cautions that the agreement is not a guarantee of permanent filtration avoidance because of changing regulations, uncertainties regarding pollution sources, advances in treatment technologies, and natural variations in watershed conditions. The book recommends that New York City place its highest priority on pathogenic microorganisms in the watershed and direct its resources toward improving methods for detecting pathogens, understanding pathogen transport and fate, and demonstrating that best management practices will remove pathogens. Other recommendations, which are broadly applicable to surface water supplies across the country, target buffer zones, stormwater management, water quality monitoring, and effluent trading.

Water is becoming increasingly scarce. If recent usage trends continue, shortages are inevitable. Aquanomics discusses some of the instruments and policies that may be implemented to postpone, or even avoid, the onset of “water crises.” These policies include establishing secure andtransferable private water rights and extending these rights to uses that traditionally have not been allowed, includingaltering in-stream flows and ecosystem functions. The editors argue that such policies will help maximize water quantity and quality as water becomes scarcer and more valuable. Aquanomics contains many examples of how this is being accomplished, particularly in the formation of water markets and market-like exchanges of water rights. Many observers see calamity ahead unless water supplies are harnessed and effectively conserved, and unless water quality can be improved. It is also clear that declining water quality is a serious problem in much of the world, as increasing human activities induce high levels of water degradation. Those who voice these concerns, argue the contributors to this volume, fail to consider the forces for improvement inherent in market political-economic systems that can address water issues. The contributors see water quality in economically advanced countries as improving, and they believe this establishes the validity of market-based approaches.

Environmental problems in coastal ecosystems can sometimes be attributed to excess nutrients flowing from upstream watersheds into estuarine settings. This nutrient over-enrichment can result in toxic algal blooms, shellfish poisoning, coral reef destruction, and other harmful outcomes. All U.S. coasts show signs of nutrient over-enrichment, and scientists predict worsening problems in the years ahead. Clean Coastal Waters explains technical aspects of nutrient over-enrichment and proposes both immediate local action by coastal managers and a longer-term national strategy incorporating policy design, classification of affected sites, law and regulation, coordination, and communication. Highlighting the Gulf of Mexico's "Dead Zone," the Pfiesteria outbreak in a tributary of Chesapeake Bay, and other cases, the book explains how nutrients work in the environment, why nitrogen is important, how enrichment turns into over-enrichment, and why some environments are especially susceptible. Economic as well as ecological impacts are examined. In addressing abatement strategies, the committee discusses the importance of monitoring sites, developing useful models of over-enrichment, and setting water quality goals. The book also reviews voluntary programs, mandatory controls, tax incentives, and other policy options for reducing the flow of nutrients from agricultural operations and other sources.