Fluctuating flow and water levels in the St. Lawrence River, whether natural or human-induced, are of concern to the various stakeholders (government organizations, research scientists, industries and the general public) that have been involved for several years in managing water resources and their use, and in maintaining the physical chemical and biological integrity of the ecosystem. Such concerns are particularly justified in the current context of climate change, which is likely to significantly influence socio-economic and environmental policy decisions. In recent years, Environment Canada research scientists have been studying the problem of fluctuating flows and water levels in the fluvial portion of the St. Lawrence. Much of their research has been carried out in the context of the work of the International Joint Commission and, more specifically, the International Lake Ontario-St. Lawrence River Study Board, which has a mandate to evaluate the procedures and criteria used to regulate outflows from Lake Ontario and manage water levels in Lake Ontario and the St. Lawrence River. This document is the product of the work of several of the above-mentioned Environment Canada research scientists. It is a synthesis of the current state of knowledge and of certain recommendations relating to the possible impacts of fluctuating flows and water levels on various environmental and socio-economic factors.

Fluctuating flow and water levels in the St. Lawrence River, whether natural or human-induced, are of concern to the various stakeholders (government organizations, research scientists, industries and the general public) that have been involved for several years in managing water resources and their use, and in maintaining the physical chemical and biological integrity of the ecosystem. Such concerns are particularly justified in the current context of climate change, which is likely to significantly influence socio-economic and environmental policy decisions. In recent years, Environment Canada research scientists have been studying the problem of fluctuating flows and water levels in the fluvial portion of the St. Lawrence. Much of their research has been carried out in the context of the work of the International Joint Commission and, more specifically, the International Lake Ontario-St. Lawrence River Study Board, which has a mandate to evaluate the procedures and criteria used to regulate outflows from Lake Ontario and manage water levels in Lake Ontario and the St. Lawrence River. This document is the product of the work of several of the above-mentioned Environment Canada research scientists. It is a synthesis of the current state of knowledge and of certain recommendations relating to the possible impacts of fluctuating flows and water levels on various environmental and socio-economic factors.

Voices for the Watershed is a unique look at the singular and ecologically inter-connected region of the Great Lakes-St Lawrence watershed, including the headwater and upland regions. With contributions from experts from the United States, Quebec, and Ontario, this book offers an accessible introduction to the issues affecting the quality of our most essential and precious of natural resources - clean, fresh water - from headwater regions downstream to the Great lakes, the St Lawrence river, and ultimately the watershed's outflow to the sea. With thoughtful words and evocative photography, Voices for the Watershed promotes understanding and examines ecological problems, describing positive environmental actions and projects as well as ongoing concerns over the effects of pollution on wildlife and human health. The underlying themes throughout are that the drainage basins and ecosystems are under siege - from reckless land use decisions, soil erosion, acid rain, and massive habitat destruction - but that the situation is not hopeless. The authors feel strongly that education about the environmental threats - in the classroom and public forums - is essential to effecting positive change, and that conservation actions by citizen groups and individuals can be a driving force in effecting substantial reforms regarding environmental legislation and practices. Voices for the Watershed is an eye-opening look at not only the problems but possible solutions to help protect and preserve this resilient natural resource on which so many depend. Contributors include Gregor Beck, Anne Bell (Canadian Parks and Wilderness Society), J. Douglas Blakey (Upper Canada College), Serge Bourdon (Chateauguay Watershed Management Agency), Robert Brander (retired U.S. Forest Service and National Park Service), Dominique Brief (Alliance for Environmental Management), Louise Champoux (Environment Canada), Bruce Conn (Berry College), Kevin Coyle (National Environmental Education and Training Foundation), Brad Cundiff (Wildlands League), Jerry DeMarco (Sierra Legal Defence Fund), Jean-Luc DesGranges (Canadian Wildlife Service), Thomas A. Edsall (Western Basin Ecosystem), Peter Ewins (World Wildlife Fund), Louis-Gilles Francoeur (Le Devoir), Stephen Gates (Grey Owl Nature Trust), Elliott Gimble (Jewish Community Relations Council), Hallett J. Harris (University of Wisconsin-Green Bay), John Hull (Quebec-Labrador Foundation), Gail Jackson (independent consultant), John Jackson (Great Lakes United), Val Klump (University of Wisconsin-Milwaukee), Louise Knox (Hamilton Harbour Remedial Action Plan), Gail Krantzberg (Ontario=s Environment Ministry), Peter Lavigne (Watershed Consultants), Michel Letendre (Quebec Ministry of the Environment and Fauna), Bruce Litteljohn, Nadia Ménard (Saguenay-St. Lawrence Marine Park), Jeff Miller (artist), Phil Norton (Montreal Gazette), Jean Rodrigue (Environment Canada), Alec Ross (writer and journalist), Scot Stewart (naturalist), Rae Tyson (USA Today), Fred Whoriskey (Atlantic Salmon Federation), with a major personal narrative by Michael Keating (environmental writer and consultant).

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.