Since the 1950s,the International Joint Commission (IJC) of Canada and the United States has issued water regulation and management plans for Lake Ontario and the St. Lawrence River. Changes in recreational, environmental, navigational and other uses of the water system have prompted the IJC to consider replacing the current water regulation plan in operation for more than 40 years. IJC's goals for a replacement plan include sound scientific foundations, public participation, transparency in plan development and evaluation, and inclusion of environmental considerations. To help develop and select the new plan, the IJC supported a 5-year, $20 million Lake Ontario-St. Lawrence River Study (LOSLR Study). The LOSLR Study uses models to compile and integrate data gathered from a series of commissioned studies of wetlands, species at risk, recreational boating, fisheries, coastal erosion and flooding, commercial navigation, hydropower, industrial, municipal and domestic water intakes, public information and education, and hydrologic modeling. This report reviews a portion of the study that focused on wetlands and species at risk and three of the models that were used. The report finds that the overall breadth of the LOSLR study is impressive, and commends the scale and inclusiveness of the studies and models. In terms of informing decision making, however, the reviewed studies and models show deficiencies when evaluated against ten evaluation criteria, including treatment of uncertainty, quality control/quality assurance, thorough documentation, and empirical foundations. Among the report's recommendations is a need for more thorough documentation of study methods and findings, stronger and more consistent quality control, and more attention to how uncertainty should be addressed to better inform decision making. This NRC study was conducted in collaboration with the Royal Society of Canada.

Where water control works or other measures appeared to be economically and environmentally practicable, the Commission was asked to determine the full costs and benefits, and indicate how the various interests on either side of the boundary would be affected. The Commission was also asked to determine the need for, and costs of, remedial or compensatory works or measures to offset costs to the interests that may be adversely affected by any proposed regulatory measure.

Water resources are under extreme pressure today all over the world. The resulting problems have given rise to many activities which reflect the growing concern about them and the importance of effective management.As water increasingly becomes a precious resource on which the well-being of future generations depends, it is essential to discuss issues concerning quality, quantity, planning and other related topics.Containing papers presented at the Fourth International Conference on Water Resources Management, this book examines the recent technological and scientific developments associated with the management of surface and sub-surface water resources. The wide variety of subjects covered are as follows: Water Resource Management and Planning; Waste Water Treatment and Management; Water Markets and Policies; Urban Water Management; Water Quality; Storm Water Management; Water Security Systems; Pollution Control; Irrigation Problems; Reservoirs and Lakes; River Basin Management; Hydrological Modelling; Flood Risk; Decision Support Systems; Groundwater Flow Problems and Remediation Technologies; Coastal and Estuarial Problems; Soil and Water Conservation and Risk Analysis.

The International Joint Commission's Levels Reference Study Board report of March 1993 recommended that the "Orders of Approval for the regulation of Lake Ontario be revised to better reflect the current needs of the users and interests of the system." In April 1999, the International Joint Commission informed the governments that it was becoming increasingly urgent to review the regulation of Lak [...] The volunteers of the Public Interest Advisory Group have been central to the success of the undertaking, contributing significantly and uniquely to the work of the Study Board. [...] The Study Board has agreed that long-term deviations from plan rules and flows have the effect of changing the intended performance of the plan(s) as designed and the benefits that flow from the plan(s). [...] Lawrence River Water Levels and Flows FINAL REPORT The basic data and information collected, the research undertaken, the models developed and the body of knowledge accumulated during the Study have many possible and potential uses beyond the review of the Commission's Lake Ontario regulation criteria and plan. [...] Lawrence River Water Levels and Flows vii FINAL REPORT Divergent Viewpoints The majority of the Study Board stands behind the planning approach, the research program and the findings and conclusions presented in this report.