Federal agencies have taken steps to include the public in a wide range of environmental decisions. Although some form of public participation is often required by law, agencies usually have broad discretion about the extent of that involvement. Approaches vary widely, from holding public information-gathering meetings to forming advisory groups to actively including citizens in making and implementing decisions.

Proponents of public participation argue that those who must live with the outcome of an environmental decision should have some influence on it. Critics maintain that public participation slows decision making and can lower its quality by including people unfamiliar with the science involved.

This book concludes that, when done correctly, public participation improves the quality of federal agencies' decisions about the environment. Well-managed public involvement also increases the legitimacy of decisions in the eyes of those affected by them, which makes it more likely that the decisions will be implemented effectively. This book recommends that agencies recognize public participation as valuable to their objectives, not just as a formality required by the law. It details principles and approaches agencies can use to successfully involve the public.

Hydrologic regimes play a major role in determining the biotic composition, structure, and function of aquatic, wetland, and riparian ecosystems. But human land and water uses are substantially altering hydrologic regimes around the world. Improved quantitative evaluations of human-induced hydrologic changes are needed to advance research on the biotic implications of hydrologic alteration and to support ecosystem management and retoration plans. We propose a method for assessing the degree of hydrologic alteration attributable to human influence within an ecosystem. This method, referred to as the "Indacators of Hydrologic Alteration," is based upon an analysis of hydrologic data available either from existing measurment points within an ecosystem (such as at stream gauges or wells) or model-generated data. We use 32 parameters, organized into five groups, to statistically characterize hydrologic variation within each year. These 32 parameters provide information on ecologically significant features of surface and ground water regimes influencing aquatic, wetland, and riparian ecosystems. We then asses the hydrologic pertubations associated with activities such as dam operations, flow diversion, groundwater pumping, or intensive land-use conversion by comparing measures of central tendency and dispersion for each parameter between user-defined "pre-impact" and "post-impact" time frames, generating 64 indacators of Hydrologic Alteration. This method is intended for use with other ecosystem metrics in inventories of ecosystem integrity, in planning ecosystem management activities, and in setting and measuring progress toward conservation or restoration goals.

The US Federal Energy Regulatory Commission (FERC) has proposed a "Cluster Impact Assessment Procedure" (CIAP) for analyzing cumulative impacts from hydropower projects on the resources of a river basin. While the CIAP is based on analyses of perceived magnitudes of impacts, it avoids any interpretation of the potential for basin-wide interaction among the projects leading to an accumulation of their effects in the resources. A measure of an "impact interaction potential" (IIP) is suggested here to describe the functional side of cumulative impacts. This tendency of a project cluster to cause cumulative impacts, or its "cumulativity", is examined through subbasin disaggregations of projects and resources. A dispersion of the project's impacts across subbasins I evaluated using linear algebra and principles of information theory. The formalized algorithm is programmed in BASIC and proposed as an IIP Assessment Loop in the CIAP. The IIP loop attaches to the Multiple Projects Assessment Phase as a causal interpretation of cumulative impacts, complementary to the effects analyzed via the CIAP's use of weighted summations. Use of the algorithm is demonstrated with a hypothetical project cluster in the Salmon River Basin (Idaho).