6.	SPECIFIC STUDIES AND EVALUATIONS OF INTERESTS

The following sections describe each of the interests that will be investigated. For each interest, a course of action is described and the agencies that will be asked to participate are identified. Approximate schedules are outlined along with cost estimates. A list of those who contributed to the detailed evaluations, which follow, is contained in Annex 5.

6.1	Wetland/Environmental Interests

6.1.1

Relationship to Water level Fluctuations

Water level fluctuations are a natural phenomenon in the Great Lakes due to natural climatic variability. For example, over the past 3000 years, Lake Michigan was less than half its current size during the mid-Holocene warming period about 8000 years ago and over the past 3000 years has seen extreme high and low lake levels approximately every 150 years (Thompson and Baedke, 1997). Outflows through the St. Lawrence River are also affected by water supplies from the lakes, and water levels in the river thus experience natural variation. The biological communities of the Great Lakes and the St. Lawrence River have, by necessity, evolved to adapt to the range of water levels and water level changes that occur on several scales, ranging from wind-driven tides or seiches that can occur several times daily, to seasonal changes each year, to longer episodes.

The biological effects of water level fluctuations in both lake and river are greatest in shallow water where even small changes in water level can result in conversion of a standing water environment to an environment in which sediments are exposed to the air, or vice versa. The localized effects of this change in the environment are most evident in the relatively immobile plant communities that occur in wetlands. In fact, the patterns of water level change are the driving force that determines the overall diversity and condition of wetland plant communities and the habitats they provide for a multitude of invertebrates, amphibians, reptiles, fish, birds, and mammals.

Due to Lake Ontario regulation, the extreme high water levels during the high water supply periods have been lowered, and the low levels during the very dry periods raised. As a result, shrubs and upland plants become established in the wet soils above the water line, canopy-dominating larger plants such as cattails crowd out other emergent plant species in shallow water, and a few competitive submersed species dominate in slightly deeper water. High water levels kill many of the shrubs and invading upland plant species; they also kill many cattails and other canopy-dominating shallow water emergents. When water levels recede, the bare sediments are exposed to the air, and the seeds of many other emergent plants are able to germinate and grow. The dominating species also grow from seed and eventually regain dominance, but the diversity of habitat provided by a diverse plant community remains for a number of years, and the plants are able to complete their life cycles and replenish the seed bank, awaiting the next cycle of high and low water levels. Extreme low water levels expose deeper nearshore areas to the air and kill the competitive submersed plant species; emergent plants grow from the exposed seed bank. When water levels go up again, many of the emergent species eventually die, a variety of submersed plants returns, and the competitive submersed species eventually dominate again, but habitat diversity for fish and other aquatic fauna has been increased for a number of years and the cycle of wetland rejuvenation has been repeated again. (Working Committee 2, 1993)

Variations in the seasonality of water level fluctuations (winter drying, winter flooding, lack of spring flooding), which are especially applicable to the St. Lawrence River, modify wetland species composition, abundance, and distribution. Such erratic variability is likely detrimental to wetlands, especially when water levels change in a rapid, unpredictable sequence.

Water level changes have seasonal implications for fauna that extend beyond the habitat provided by a diverse plant community. Access to habitat used by fish for spawning, adult-feeding, and rearing of juveniles may be precluded by low water levels, especially in early spring. Use of wetlands as staging areas for waterfowl may be precluded by low water levels in the spring or fall. Low water levels in the winter may restrict use of wetlands by muskrats. Although occasional low water levels may restrict fish access and wetland use by wildlife in some years, this is a natural condition that has historically resulted in differences in year-class strength and natural population dynamics. The occasional low water levels also improve habitat. However, if seasonal water levels are low every year and do not allow access to or use of critical habitat at the required time, an overall decrease in population will eventually result for all wetland-dependent species.

Changes in water levels and flows also affect fauna in open-water, fast-flowing habitats of the St. Lawrence River. These include impacts to fast-water spawning grounds resulting from siltation of gravel beds under reduced current velocities and spring flushing. Changes in water circulation, speed of currents, water-renewal time, and retention areas may also exert strong effects on the components of the pelagic zone (phytoplanktonic algae, zooplankton, and larval fish). The propagation and transmission of aquatic parasites through the food chain to fish and birds could be enhanced by low current-discharge conditions. Settlement and recruitment of zebra mussels is also favored under low current-discharge conditions. Reduction in current may also alter drift of larval and juvenile fish such as sturgeon, which rely on currents to reach to their rearing habitats.

6.1.2

Past Studies

Field studies conducted under the direction of the Natural Resources Task Group of Working Committee 2 of the IJC Levels Reference Study concluded that different wetland plant communities have developed at different topographic elevations in Lake Ontario in response to water level history. Plant communities at a higher elevation that had not been flooded since 1952 were dominated by grasses, old field plants, and shrubs; over half of the taxa growing at that elevation were upland species. Plant communities at a lower elevation that had not been dewatered since 1964 had the lowest species richness and were dominated by several submersed species. At elevations that were alternately flooded and dewatered on a more frequent basis, species richness of wetland taxa was greatest. However, many of the dominant taxa across all elevations were introduced species (exotics) or otherwise considered undesirable because of invasive, weed-like habits. The lack of high lake levels in recent years was cited as the likely cause for dominance by invasive emergent taxa; the lack of low lake levels was the likely cause for dominance of submersed species. Altered seasonality of water level changes was also noted (i.e., exaggerated wintertime drawdowns resulting in springtime water levels too low to flood wetlands) and cited as a deterrent to fish access to wetlands for spawning in the spring.

The Natural Resources Task Group sought to develop a draft regulation plan for Lake Ontario that increased the frequency and amplitude of high and low lake levels to more closely approximate natural conditions and thus reduce environmental impacts of regulation. A preliminary recommendation for accomplishing this task was developed based on pre-regulation lake level variability. Modeling of this regulation plan was based on actual past inflows and resulted in modeled lake levels in several years in the 1970s and 1980s that would likely be considered unacceptable by other interests. Therefore, another preliminary recommendation was developed that used the highest and lowest lake level constraints of the current regulation plan but added more variability in water levels between years. When potential responses of wetland plant communities to this proposed plan were compared with other regulation plans under evaluation, the proposed plan showed some improvement in increasing the area of wetland subjected to both flooding and dewatering conditions and thus increased habitat diversity. However, development and testing of this plan was based on biological and topographic data collection at a limited number of actual field sites. In addition, the required frequency of high and low water level events was determined from the modern record, which is too short to show long-term trends. The development process for the plan was also unable to address the seasonality problem, in which many wetlands remain dewatered during the critical seasons when they are used by fish and wildlife, because the topography information was not suited to the task.

Previous studies of Lake Ontario resources and problem areas have led to the development and implementation of Remedial Action Plans, some of which (Cornwall, Bay of Quinte, Hamilton Harbour) address specific concerns over the impacts of fluctuations of water levels on wetlands and other restoration projects. St. Lawrence River and Great Lakes Action Plans comprise a number of studies that provide background environmental information that could be used to address the issue of environmental impacts of water level fluctuations, including limnological characteristics, a detailed inventory of the shorelines of the St. Lawrence that characterizes riparian habitats, and a regional atlas of sensitive zones of the St. Lawrence River corridor for the sector between Cornwall and the Gulf of St. Lawrence. Pertinent information may also be found on various environmental aspects (habitats, fish, wildfowl) in the reports released for the St. Lawrence-FDR Power project Relicensing application. The seasonal habitats requirements of many species of fish, wildfowl and mammals relying on lacustrine wetlands and fast-flowing riverine habitats for different parts of their life cycle can be documented from studies carried out either directly within the Great Lakes-St. Lawrence Basin or indirectly derived from studies in neighboring basins.

6.1.3

New Study Scope, Data Collection Needs and Evaluation Methods

Studies required to determine the effects of past water level regulation on biological organisms and their habitats, water-depth and water-flow needs of plants, fish, and wildlife, and the potential effects of proposed new regulation plans on biota and habitat are similar on Lake Ontario, the international portion of the St. Lawrence River, and the lower St. Lawrence River. They will be approached in a similar manner in all regions. However, although similar in many respects, the specific requirements of the studies differ for the regulated water levels above the dam at Cornwall and the regulated levels and flows of the lower St. Lawrence River because they represent different types of ecosystems. Therefore, specific details of recommended studies are provided in separate subsections below for regions above and below the dam.

All Regions

In all regions, the important concerns relating to water level fluctuations are the seasonality of water levels, the range in amplitude of water levels across multiple decades, and the frequency of high and low water level events. The most important feature of water level fluctuations in shallow water areas is the resultant change in water depth, which is determined by lake or river level coupled with bathymetric and topographic data. Thus, a primary need in all regions is bathymetric and topographic maps with close contour intervals. Acquisition of these maps was addressed in Section 4.2 of this POS titled Common Data Needs, although additional detailed data collection will be required for wetland study sites in all regions. The composition and diversity of wetland plant communities in the lake and river will be studied in the field and correlated with changes in water depth through time to allow modeling and prediction of the effects of different water level fluctuation patterns on wetland habitat. The accessibility and availability of useful habitat for important fish, waterbirds, and mammals will be evaluated in both lake and river also. Critical aspects of this work are surveying the elevations of access routes between wetlands and the lake or river to identify water levels required to allow wetland access, gathering existing data on fish and wildlife use of study wetlands, searching the literature for information on the seasonal water-depth and habitat needs of various species, and evaluating the potential availability of those depths and habitats using the bathymetric/topographic data and plant community analyses.

The faunal studies will largely address the seasonality requirements of water levels. Wetland plant studies will address the multi-decadal range of water levels required to sustain viable wetland habitats. The required frequency of high and low water years across multi-decadal periods will be determined by using geological techniques to produce a long-term lake level curve for Lake Ontario. That long-term water level history can then be applied to flow characteristics in the St. Lawrence River to provide information on the natural variability of water levels and flows in the river. The influence of hydrology on wetlands has two components, amplitude and frequency. The long-term water level history is critical because it identifies the characteristics of both components that resulted in naturally sustaining wetland communities in Lake Ontario and provides the basis for recommendations on the optimal conditions that would best maintain diverse wetland habitats and associated biological communities.

The results of the studies described above will be used to formulate water level-regulation scenarios that best meet the needs of the affected biological communities in both Lake Ontario and the St. Lawrence River in terms of amplitude, frequency, and habitat access and use. Since lake and river habitats and communities differ, their optimal scenarios may differ. Releases of water from Lake Ontario will largely dictate conditions below the dam on the St. Lawrence River; releases that are optimal for one side of the dam may not be optimal for the other side. Therefore, lake and river study teams will coordinate efforts in scenario development to generate options that can best meet the needs of both lake and river without deleterious effects on the other. This effort will require considerable assistance in hydrodynamic modeling, which is also discussed in Section 7.0 titled Hydrologic and Hydraulic Evaluation.

In addition to scenario development, the results of the studies will be used to create models for use in evaluating scenarios proposed by other interests. These models will include reference to seasonality of water level changes as required by fish and wildlife, to the amplitude of water level fluctuations that result in habitat development, and to the frequency of high and low water level/water-flow events that determine cycling of habitat changes and result in habitat diversity.

1. Lake Ontario and International Portion of the St. Lawrence River

Information needs required to assist in development of refined criteria and a new regulation plan for Lake Ontario and portions of the St. Lawrence River above the dam at Cornwall must be centered on collection of more thorough topographic/bathymetric data at an increased number of wetland sites, concurrent collection of plant community data to reflect changes that have occurred since the Levels Reference Study data collection in 1991, collection of data relating to fish, waterbird, and mammal accessibility to and use of wetland habitat, and development of a long-term lake level record that defines the natural variability and frequency of changes in water levels, thus forming the foundation for understanding the conditions under which natural systems developed and can best be sustained. Site selection for study of modern wetlands will be based on several factors: wetlands protected from wave attack by barrier beaches or in river mouths, thus retaining organic sediments and developing a flatter topographic profile; wetlands exposed to wave attack, thus having predominantly inorganic sediments and a steeper topographic profile; wetlands identified as potentially critical spawning habitat for fish such as northern pike that enter wetlands in early spring; wetlands used as major staging areas for waterfowl or as feeding areas for shorebirds; wetlands historically used by muskrats during winter; wetlands without obvious signs of other human disturbances; and, to the extent possible, wetlands distributed geographically around the lake and in the international portion of the river.

Topographic data collection will consist of developing detailed maps of small wetlands or representative portions of larger wetlands and, in the case of barrier-beach-protected wetlands and shallow river-mouth wetlands, will include the topography/bathymetry of that portion of the wetland where hydrologic connection is made with the lake and fish access becomes critical. Plant community data will be collected by sampling along topographic contours that represent different flooding/dewatering histories associated with past lake level changes. Fish, waterbird, and mammal habitat requirements will be researched from existing literature, and available data sets on actual wetland use by those biological communities will be retrieved from cooperating federal, state, and provincial resource agencies. If critical data are not available, limited field data collections will be conducted.

Proposed new regulation plans that would benefit wetlands will be based on these data and evaluations of the amplitude and frequency of water level changes derived from long-term lake level studies. The potential response of wetland vegetation and associated habitat in Lake Ontario and the international portion of the St. Lawrence River to all new proposed regulation plans will be evaluated for both the protected/organic and the exposed/inorganic wetland types. These evaluations will be based on data that show the past response of plant communities at specific elevations to changes in lake level, which will then be overlaid on topographic/bathymetric models that allow potential distributions of plant communities to be weighted by the area encompassed by various water-depth intervals.

Seasonality of water level patterns in proposed regulation plans will be evaluated based on fish-access data derived from topographic/bathymetric surveys and area of wetland with suitable water depths for staging waterfowl, feeding shorebirds, or overwintering muskrats, each in the appropriate season. These data will be incorporated into the topographic/bathymetric model.

Reconstruction of long-term lake levels for Lake Ontario requires the collection of information that indicates past elevation of the lake and the time that the lake was at that elevation. These data may be from sites that are above water or below water. The rebound history of Lake Ontario resulting from melting of glaciers long ago is such that most of the lake level record is below water, although some above-water data exist as barrier beaches, spits, and beach ridges. Below-water data occur as sedimentary deposits in lagoons and drowned river mouths around the lake. Sediment cores will be collected to recover records of lake level history. The lake level signal within the deposits may be physical, biological, or chemical; the actual data needed vary between study sites. Data from above-water sources may consist of the elevation of specific sediments in old barrier beaches that define the lake level at the time the beach was formed; they may also be in the form of the elevation of fluvial terraces. Data from below-water sources may consist of the elevation of dateable horizons that contain indicators that can be used to approximate the water surface at the time of deposition. A long-term lake level study must collect data from several sites and use them to create individual "relative" water level curves for each site, which can then be combined by subtracting differences in rebound among sites. The result will be a lake level curve that indicates fluctuations observed at the outlet to the St. Lawrence River and long-term rates of rebound. This lake level curve will not only describe the high and low elevations of lake levels in the past, it will describe the frequencies at which Lake Ontario reached those elevations. The frequency information is required to define the timing of proposed high and low lake levels under all potential regulation plans that might benefit wetlands. This issue will be of critical importance when all interests attempt to reach consensus on a new regulation plan. The long-term lake level curve will determine whether wetlands require periodic high and low lake levels approximately every 13 years as suggested by the modern record, every 30 years as suggested by the Lake Michigan/Huron lake level record, or perhaps some different interval. Both frequency and amplitude information will also provide important information on expected responses of lake level to future climate changes and should benefit other interests in their efforts to plan realistically for potential extreme high and low water level periods in the future.

2. Lower St. Lawrence River

Studies directly pertaining to the environmental components on the St. Lawrence River can be divided into three groups: littoral and riparian habitats (wetlands), pelagic zone habitats, and vertebrate fauna. The biological information gathered on each of these topics will be integrated with topographic-bathymetric-hydraulic information into a model allowing the response of each component to variations in water level and habitat components to be identified.

Wetlands are the areas in which the impacts are the most obvious, and they offer the greatest potential to integrate impacts on fish, amphibians, reptiles, wildfowl, and mammals; specific studies are warranted to examine critical aspects of certain species' life cycles. Wetland distribution and characteristics will be updated through the acquisition of recent remote sensing information (aerial photographs or satellite imagery) and validated with field surveys. Because submerged vegetation cannot be quantified adequately from aerial photographs, a model allowing prediction of distribution and biomass from a set of environmental variables (depth, transparency, etc.) is required. In conjunction with knowledge of the current and past distribution of wetlands obtained through aerial photographs and satellite imagery, topographic-bathymetric information and water level modeling will allow changes in surface area of riparian habitats subjected to different hydrologic regimes to be quantified. Field studies are required to determine the speed of recovery of emergent and submerged vegetation following cycles of drying and flooding, both in terms of species composition and biomass. Given the dynamic nature of fluvial hydrology and the large spatial and temporal variability of riverine wetlands, multi-year monitoring of permanent sites may be required to model the response of shoreline habitats to water level fluctuations, to assess the speed of recovery of the vegetation after episodes of flood or drought, and to document the mechanisms by which aquatic plant communities adapt to such variations. Existing monitoring surveys aimed at hydrology, water quality, fish communities, and other bio-physical indicators will be maintained since they provide a unique, long-term data series that allows past conditions to be investigated.

Impacts on open-water, fast-flowing habitats in the St. Lawrence River will be evaluated and forecast by studying the relationship between water circulation (current speed, water-renewal time) and phytoplanktonic production, biomass accumulation (algal blooms), and proliferation of blue green algae responsible for noxious smell and toxins. Similarly, the relationship between discharge and zebra mussel recruitment will be monitored to assess the discharge threshold and the critical period over which proliferation is to be expected. The effects of reduced water circulation and lower current speed under low discharge on recruitment and habitat availability for open-water fish species such as sturgeon and walleye will be assessed. As with the information pertaining to riparian habitats, the interaction of biological information with physical characteristics of circulation will be documented by integration with a hydrodynamic model.

Certain species of vertebrate fauna (fish, wildfowl, and mammals) of particular interest (exploited, keystone, sensitive, or endangered species) may require specific studies to assess their individual responses to water level fluctuations, especially for those species that require complex combinations of seasonal flooding, temperature, and habitat requirements. The hydrologic conditions that are critical for different stages of species' life-history must be defined, including the seasonal timing, duration and frequency of flooding and dewatering of spawning, nesting, feeding, rearing, and overwintering habitats. The characteristics and locations of fish spawning and reproductive sites in the St. Lawrence River are known for a number of species; however, this information must be completed, assembled, and compared to other physical and biological data to quantify the availability (and vulnerability) of habitats for major fish assemblages. Complementary information on growth, migration patterns, and food-web processes will also be gathered, since these factors may also affect abundance, biomass, quality, and desirability of economically valuable species in the St. Lawrence River. Similar information will be assembled for waterfowl and mammals of particular interest. The surface area of habitat available for wildfowl under different water level scenarios, the carrying capacity of current habitats, and specific wildfowl requirements with respect to seasonal water levels will be assessed. This requires completion of information for each species and identification of keystone faunal assemblages for the St. Lawrence River. For each of these assemblages, habitat requirements will also be compared to current physical and biological conditions to locate and quantify the availability and vulnerability of habitats for vertebrate faunal assemblages.

The impacts of water level fluctuations on wetlands, open-water habitats, and vertebrate fauna will be quantified for different St. Lawrence River discharge scenarios, in order to assess the response of individual biological variables of interest. This will be achieved through the integration of biological and physical-environmental information using superimposition of multiple layers of information: bathymetry/topography, sediment composition, water circulation and currents, emergent and submerged aquatic plant distribution, biomass, and community types, and location of known spawning, nesting, and overwintering sites for given vertebrate species of particular interest. This requires major contributions from the information gathered under Section 7.0 (Hydrologic and Hydraulic Evaluation), especially since about 20% of the St. Lawrence River flow originates from the Ottawa River. Other physical-environmental data needs are described under the common data need section (section 4.2). Integration of biological data with physical data requires the organization of available biological information on a numerical, georeferenced basis at spatial and temporal scales that are mutually compatible and relevant to each variable. For this purpose, special emphasis will be placed on georeferenced information (aerial photographs, satellite imagery, georeferenced data bases), allowing the state of past and current resources to be mapped and superimposed on different types and levels of information through GIS applications at appropriate scales.

The next step lies in the elaboration of quantitative relationships (models) between given environmental and biological variables, allowing inference of the direction and magnitude of biological response to changes in discharge and water levels. For example, the topographic/bathymetric charts can be superimposed with maps of spawning grounds and bottom sediment composition. Water depth covering these areas over different critical periods for spawners can then be modeled from hydrologic information, thus allowing the sensitivity of known spawning sites and the availability of other potential spawning sites under various discharge scenarios to be assessed. Similar integration procedures will be used for other biological components to identify the water level/discharge conditions that maximize the surface area of wetlands, favor plant species and/or habitat diversity, maximize the surface area of different species' habitat for given (seasonal) life stages, or identify critical current conditions that minimize the proliferation of undesirable planktonic algae, parasites, and zebra mussel larvae.

6.1.4

Implications of Climate, Demographic, and Other Changes

In wetlands with wet soil and no standing water, the relative inputs of ground water will likely dictate water availability and the fate of the wetlands under climate-change conditions. Wetlands in basins restricted by steep adjacent uplands, offshore deep waters, or unsuitable substrate type will likely decrease in size; other wetlands in suitable settings might shift to lower elevations. Climate warming that resulted in decreased water supplies could force lower lake levels that have been absent from Lake Ontario since regulation began, expose sediments, and result in an increase in emergent vegetation. Low lake levels for extended periods could have serious impacts on fish access to wetlands and other critical habitats. In areas with extensive human development along the shore and armoring of the shoreline, the ability of wetland plant communities to shift position with respect to water depth would be restricted.

A lowering of freshwater flow and spring peak freshet flows in the St. Lawrence River and estuary would have major negative impacts on the ecosystem from Montreal downstream through the Gulf of St. Lawrence. The viability of the lower section of the river and the Gulf of St. Lawrence is highly dependent on the large freshwater inflow from upstream and the cyclical seasonal nature of this flow. If freshwater flow to the estuary were to be significantly reduced, upstream migration of the saltwater front and significant changes in freshwater-flow-induced currents in the lower river and Gulf of St. Lawrence would likely result and could be catastrophic to fisheries and current biological systems.

A reduction in water depth in the St. Lawrence River would result in greater pressure for additional channel dredging, which in turn would increase channelization effect, accentuate the hydraulic isolation (and the eventual drying up) of shallow areas, increase water temperature, plant biomass production, and local retention of organic matter. This would cause a further dewatering of valuable fish and wildlife habitat in the littoral areas, which are especially important in shallow fluvial lakes. These cumulative physical environmental modifications would markedly modify the surface area and the qualitative characteristics of fish and wildfowl habitats. Lower water levels would result in increased resuspension of shallow-water fluvial lakes and riverine sediments, with consequent effects on turbidity and the resuspension of in-place pollutants, especially in navigation channels. Lower pollutant dilution and increased resuspension may result in exposure of organisms to higher levels of contaminants.

Demographic changes that result in increased shoreline development could affect the nearshore environment. When shoreline protection is constructed, natural sediment-transport processes are altered, and erosion of barrier beaches and other protected wetland environments increases. Increases in human populations can result in construction of new highways near the lakeshore or across the river floodplain. Where these highways cross riverine wetlands adjacent to the lake, flow restrictions under bridges or through culverts also disrupt sediment transport processes and can result in excessive siltation in the wetland. Encroachment can result in direct loss of nearshore environment and chemical contamination of that environment.

6.1.5

Optimal Conditions

Studies to date indicate that optimal water levels for maintaining diverse wetland habitats and associated biological communities should mimic the natural pattern of fluctuations as nearly as possible. The natural pattern will be quantified by development of a long-term lake level history for Lake Ontario that describes water level changes over the past several thousands of years, as has been done for lakes Michigan-Huron (Thompson and Baedke, 1997) and is underway for Lake Superior. This long-term history can then be compared with daily values for water levels under pre- and post-regulation regimes to generate information on expected flows in the St. Lawrence River upstream and downstream from or influenced by major tributaries (especially the Ottawa River, which produces an important seasonal signal).

6.1.6

Study Organizations, Costs, and Schedule

1. Lake Ontario and International Portion of the St. Lawrence River

The suggested leads for the Lake Ontario/international portion of the St. Lawrence River component are the U. S. Geological Survey, Great Lakes Science Center located in Ann Arbor, Michigan and Environment Canada, Ontario Region located in Toronto, Burlington, and Guelph, Ontario. Support will be provided by other agencies including Department of Fisheries and Oceans, Ontario Ministries of Environment and Energy and Natural Resources, U.S. Fish and Wildlife Service, U. S. Environmental Protection Agency, New York State Department of Environmental Conservation and other academic and environmental organizations. A listing of suggested agencies is given in Annex 1.

Table 2a gives a breakdown of costs in U. S. dollars for U. S. participation in evaluating Lake Ontario/international portion of the St. Lawrence River components.

Table 2a. Time and Cost Estimate - Wetland and Environmental Studies (U.S. $K)

Table 2b gives a breakdown of costs in Canadian dollars for Canadian participation in evaluating Lake Ontario/international portion of the St. Lawrence River components.

Table 2b. Time and Cost Estimate-Wetland and Environmental Studies (Cdn. $K)

2. Lower St. Lawrence River

The suggested lead for the lower St. Lawrence River component is Environment Canada, Quebec Region-Centre Saint-Laurent located in Montreal, Quebec with support from the Ministère de l'Environnement and Faune et Parcs Québec along with other academic and environmental organizations.

Table 2c gives the breakdown of costs for evaluation the lower St. Lawrence River component in Canadian dollars.

Table 2c. Time and Cost Estimate-Wetland and Environmental Studies for the lower St. Lawrence River (Cdn $K)

Note in Table 2c: Topographic data acquisition and hydrodynamic modeling steps are not included in the budgetary estimate presented above. In addition, some of the basic biological information required for the purpose of environmental assessment is currently gathered through regular programs of Environment Canada and Faune et Parcs Québec, via the St. Lawrence Action Plan Phase III (1998-2003). Those current programs will have to be modified and adapted to answer the specific questions asked by the IJC, so as to emphasize the integration of topographic-bathymetric-hydrodynamic information with biological data.

Table 2d. Total Time and Cost Estimates - Environment/Wetlands

6.2	Recreational Boating Interests

6.2.1

Relationship to Water Level Fluctuations

There are 200-250 marinas on the U.S. shores from Porter, New York to Massena, New York. In Canada there are over 200 marinas including yacht clubs from Niagara-on-the-Lake on Lake Ontario to Trois-Rivières on the St. Lawrence River. In addition, there are a number of publicly accessible ramps and docks. The boating season stretches from about the first of April through to the end of October. During this period boaters are susceptible to fluctuating water levels.

When water levels are low, some boaters do not have sufficient depths to launch their boats in the spring, haul out in the fall, or operate in shallow areas and entrance channels. Other problems include increased incidence of damage to propellers, shaft, and hull. When levels are high, fixed docks and buildings may become inundated. Other problems include reduced bridge clearances and submerged water hazards.

If boaters are unhappy with their access capabilities as a result of high or low water levels, this has a direct impact on marina owners and the local tourism industry. Typical losses may include summer and winter storage, crane fees, service fees and in some cases loss of retail sales. Dredging and floating docks are corrective measures but may be too costly and time-consuming for some. Historically, boater reaction to water access constraints have included: moving to another marina or area, quitting boating, or acquiring a smaller boat that requires less depth.

6.2.2

Past Studies

The 1981 report to the IJC by the International Lake Erie Regulation Study Board contains some information on the potential impacts on recreational boating if Lake Erie were regulated. Only marinas on the United States shores were studied.

The recent Levels Reference Study (1993) examined the impacts of water levels on recreational boating. Site specific marina and boater survey information was gathered for 43 U.S. marinas in the Alexandria Bay, New York area. Stage damage curves were prepared on a reach basis based on the survey results and used to evaluate numerous measures being examined as part of the Levels Reference Study.

The 1993 Reference Study also examined eight Canadian marinas in the Kingston - Brockville reach of the St. Lawrence River which were surveyed in October 1991. On Lake St. Louis, seven Canadian marinas were surveyed in the same period. Based on the data collected, available depths corresponding to the time of the survey, optimum depths, critical maximum and critical minimum depths were identified. The investigators also derived an average operating range for the marinas at the two sites. In addition, operating ranges were also developed based on the September-December 1991 mail survey results. A study conducted in 1998 by the Quebec Marine Trade Association and the City of Montreal examined recreational boating in Quebec and the development potential in the greater Montreal area. A 1998 report by Environment Canada, Fisheries and Oceans and the Quebec Ministry of Environment and Wildlife identified 69 marinas between Cornwall and Quebec City, 51 public ramps in the same sector and 30 docks.

6.2.3

New Study Scope, Data Collection Needs

In order to establish water level criteria for recreational boaters, it is necessary to develop a relationship between water level and boater impacts. It is proposed that some form of impacts model be developed which puts a value on the damages experienced by the recreational boating interest as a result of high or low water levels and the secondary or indirect effects on the local economy. The following outlines the tasks required to establish water level criteria for the recreational boating interest.

Task 1: Development of Water Level - Recreation Boater Impact Model

The basic premise for the impact model is that a boat has a minimum acceptable level to operate and a maximum level based on top of dock elevation or other physical parameter. There are various measurement standards and procedures to measure impacts. The evaluation method from the Levels Reference Study will be reviewed and updated as needed to develop a boater impacts model.

One practical measure of boater impacts resulting from incremental changes in water levels can be ascertained by estimating the corresponding number of boats that cannot be used due to high or low levels. Depending on the level of details and the method used to take into consideration the various interests, the impacts on recreational boating can further be expressed in monetary terms based on certain assumptions. Willingness to Pay (WTP) is a common standard used to express the monetary value of recreational outputs. Contingent valuation methods (CVM) obtain estimates of changes in recreational value by directly asking individuals about their willingness to pay (WTP) for changes in quantity of recreation at a particular site. Total WTP can be measured by aggregating individual values by summing the WTP for all users in the area. This method of evaluating impacts, among others, will be evaluated for use in this study. As a minimum, this study should evaluate boating impacts in terms of boater-days loss due to water level fluctuations.

The water level/boaters impact model can also be developed to predict financial impacts to marinas and indirect impacts to local economy.

Task 2: Physical On-Site Survey

To acquire data for the model, a field survey of all marinas on Lake Ontario and the St. Lawrence River will be conducted. Each marina's fleet mix distribution of required drafts can be ranked and matched with the marina's corresponding available depths. The number of boats that are impacted will be measured for changes in the water level. The data will be used as the primary basis for developing water level/boater impact curves. Each marina's water level vs. number of boats impacted curve will be aggregated for each major hydraulic reach on Lake Ontario and St. Lawrence River. Among the data to be collected are the water level operating range for which each marina was designed and built, and the number of years of operation for comparison against expected reasonable conditions for marinas to operate.

Physical characteristics and usage data will also be collected for public ramps and municipal docking facilities to capture impacts to boaters not using marina facilities and to develop impact curves for this boating sector.

Task 3: In-depth Marina Operator Surveys

To augment the field surveys, a questionnaire is proposed to capture views of marina operators regarding the physical and economic impacts of fluctuating water levels, changes in fleet, perceived optimum ranges, and criteria review. The information will be used to support the impact curves and to cross-reference on-site survey results. Also included will be a determination of the number of years of operation of each marina or yacht club.

Task 4: Boater Surveys

1. Permanent Base Boaters:

To capture current boating characteristics (including days of usage, number of passengers, favourite destinations and uses, i.e. sport fishing, etc.) attitudes, opinions, perceptions and estimated boating value of the permanent base boaters, a survey questionnaire will be administered to a sample of the boating population including charter boaters and sport fishing boaters.

2. Trailer Drawn Boaters:

To capture boating characteristics of the trailer drawn boater, a short survey will be developed and conducted at public ramps, boat shows and boater magazines. Results for this survey will be used to represent the views of the small craft/casual boater that may not be represented by the marina or permanent based boater surveys.

Task 5: Regional Impacts

To establish the relationship between the boating interest and the local economy, regional impacts to the tourist industry/service sector will be assessed.

Task 6: Data Management and Analysis

All data gathered will be stored in a Geographic Information System. The data will be analyzed to develop recreational boater impact curves. These water level/boater impact curves will form the basis for the boaters impact model.

Task 7: Model Application and Documentation

Once the data have been gathered and analyzed and impact curves have been developed, the model will be run with various water level scenarios including climate change.

6.2.4

Implications of Climate Change, Demographic and Other Changes

Water level changes brought on by climate changes could have significant impacts on the boating interest. Adaptation would be very costly and would include dredging, changing slips and docks, and relocating facilities. There may be considerable regulatory hurdles associated with adaptive measures such as dredging, particularly in areas where sediments are too contaminated to be sidecast. The proposed methodology outlined above will consider climate change scenarios through a sensitivity analysis.

The recreational boating industry has been growing steadily over the last 30-40 years. Boats are much larger and have greater drafts. Given that the number of marinas which can be built is limited, and given the effects of the demographic bubble (baby boomers) about to retire, saturation could be attained within the next 10-20 years. Growth in boat size may level off at an average length of 30-35ft. (10-12 metres), draft of 5-7ft. (1.5-2.1 m), and maximum 50ft. (15 m) at draft of 8ft. (2.4 m). Another factor is the cost of fuel. In periods when fuel costs are high, there is a tendency to deeper draft sailboats and vice versa. Whether these hold true is difficult to say, but consideration should be given to trends in the industry. The model will evaluate impacts to boaters based on future trends through a sensitivity analysis.

Since Sport Fishing and Charter Boats have different use patterns, separate impact curves will have to be developed for these activities.

6.2.5

Optimal Conditions

For each marina, there is a range of water levels where optimum conditions exist for the marina's operation and for all of its users. As water levels extend beyond this optimum range, adverse impacts will begin to occur. The optimum ranges for each marina (within a hydraulic reach) can be combined into one collective optimum range relationship which comprises a water level range where no adverse conditions exist for any marina within the reach or at least where adverse conditions are minimized. Preference indicators for the recreational boating interest were developed during the development and testing of Regulation Plan 1998, and another type of Lake Ontario regulation plans called the Interest Satisfaction Model. This information needs to be verified through comprehensive field surveys.

6.2.6

Study Organization, Costs and Schedule

The suggested agencies that will perform this work are listed in Annex 1. The following lists the proposed work items along with cost estimates and schedule. Depending on the levels of detail required of the study, the tasks will be ranked in order of importance and as to whether they help address the issues. The level of detail for field data collection should be consistent with the evaluation method and for this reason, early development and testing of the evaluation method is essential. A pilot study using several typical marinas to test the evaluation method will be conducted prior to any full scale field data collection program.

Table 3a. Time and Cost Estimates - Recreational Boating Studies (U.S. $K)

Table 3b. Time and Cost Estimate - Recreational Boating Studies (Cdn. $K)

6.3	Coastal Zone Interests - Riparian/ Shore Property Erosion and Flooding

6.3.1

Relationship to Water Level Fluctuations

The fluctuation of the water levels in the Great Lakes and St. Lawrence River affects most of the coastal zone interests either directly or indirectly. High levels as experienced in the mid-1940s, early 1950s, 1970s, mid-1980s and again in 1993 are of concern to those who live along the Great Lakes and St. Lawrence River shoreline since they can combine with other factors, such as storm waves or ship wakes, to cause serious flood and erosion damage. Low levels as experienced in 1934-36 and 1964-65 increase the shore area, but can also impact water intake structures, ramp and docking facilities, water quality, and can lead to the undercutting of shore protective works.

Lake Ontario is diverse geomorphically, with its shoreline falling into all shore types. The St. Lawrence River is dominated by a low plain shoreline. Both the Canadian side of Lake Ontario (particularly the western shoreline), and along the St. Lawrence River have a relatively high percentage of shore protection (10.7% and 12.7% respectively) due to intense residential and industrial development, while the U.S. side of Lake Ontario is largely unprotected with only 1.3% classed as artificial shoreline (Working Committee 2, 1993). Surveys conducted during the Levels Reference Study revealed that erosion is a more common problem than flooding to shoreline residents. Nevertheless, flooding has been a major concern, especially in several areas of the U.S. shore of Lake Ontario (particularly west of Rochester NY and along the eastern shore of the lake) and in the Montreal area of the St. Lawrence River. The percentage of property owners stating that they had experienced low water level impacts was almost the same as the percentage experiencing high water levels. This was despite the fact that these surveys were conducted following a 20-year period of above average water levels. The true impacts of below average water levels, especially for an extended period, are not well understood.

Stage damage curves used during the Levels Reference Study indicated the highest potential damages due to flooding are along the St. Lawrence River. Flood levels on the St. Lawrence River in the Montreal Region generally result from the combined effect of high St. Lawrence River flows, high Ottawa River flows and local inflows. High St. Lawrence River outflows may contribute to flooding on Lac Des Deux Montagnes and the Back Rivers (Rivière Des Prairies and Rivière Mille Iles) as well as on the main stem of the St. Lawrence.

Storms combined with high water levels were seen as the main cause of both flooding and erosion by Lake Ontario riparians. Those living along the St. Lawrence River, identified high water levels and ship wakes as the main causes identified for flooding and erosion (Working Committee 2, 1993). This is supported by a recent report (Davies, M.H. and Watson, D.A.W., 1999) that found that ship-driven waves may have substantial effects on shoreline erosion and property damages dependent on water levels relative to river banks. This is particularly the case with the islands in the St. Lawrence River, some of which have already disappeared completely.

From a geomorphological standpoint, fluctuating water levels and flooding and erosion are natural components of the lake and river dynamic processes. Although a reduction in the range of levels may reduce erosion of the back beach in some areas, accelerated erosion of the underwater portions of the nearshore profile are likely to occur. Many coastal areas will continue to erode to varying degrees regardless of changes in water level and flow regimes (Working Committee 2, 1993). The implications to coastal processes of an extended period of low water, and/or, of an increased water level range, particularly within the Great Lakes, has not been well investigated. Low water does not necessarily mean that wide sandy beaches will evolve throughout the system. During lower water levels less new sand will enter the system, and existing sand resources may, in certain areas be displaced further offshore. During low water levels, it is expected that there will be increased downcutting of the offshore cohesive bed, steepening the offshore portion of the profile. More boat grounding, greater need for dredging, increased icejam induced flooding and the mobilization of underwater contaminated sediments are other examples of low water impacts.

6.3.2

Past Studies

In 1972-73, record high water levels in the Great Lakes caused extensive shore property damages. The Government of Canada and Ontario surveyed the shoreline and subsequently prepared a report titled "The Canada/Ontario Great Lakes Shore Damage Survey" which compiled details of areas where flood and erosion risk are highest and recommended how future damage might be reduced (EC, OMNR, 1975).

In 1986, following another period of record high levels for this century, the governments of Canada and the United States asked the IJC to examine and report upon methods of alleviating the adverse consequences of fluctuating water levels in the Great Lakes - St. Lawrence River Basin. A comprehensive Levels Reference Study ensued and numerous studies were carried out on the impacts of water levels on the shoreline. With respect to the coastal zone, a shoreline classification was developed for the entire Great Lakes shoreline identifying the make-up of the shoreline on a reach by reach basis. Stage damage curves developed a decade earlier during the high levels of the 1970s were updated to reflect current dollar values and a critical review of these curves was completed. An extensive survey of shoreline property owners was undertaken to acquire input on damages and views for solutions to the problem. (Levels Reference Study Board, 1993).

Following the Levels Reference Study, and in response to recommendations made by the IJC, the Detroit District of the U.S. Army Corps of Engineers (USACE) initiated in 1996 a Lake Michigan Potential Damage Study to provide an extensive assessment of potential shoreline damages due to changes in Lake Michigan water levels over the next 50 years. (Nairn et. al., 1999). Likewise, the Buffalo District of the U.S. Army Corps of Engineers initiated the Lower Great Lakes Erosion Study which began in 1998 with a goal of developing a tool for the assessment of local and regional impacts associated with coastal projects on Lakes Erie and Ontario (Stewart, 1999).

No comparable basin-wide effort has been initiated on the Canadian side of Lake Ontario. However, a number of shoreline Conservation Authorities in Ontario have developed comprehensive shoreline management plans for addressing the flooding and erosion issue which may be of great benefit in conducting such a task.

In Quebec, detailed maps now allow the identification of sectors most prone to erosion in the St. Lawrence, from Cornwall to downstream of Quebec City (ARGUS for Environment Canada, 1996, Argus 1991), together with a variety of restoration techniques for different situations. Erosion studies were conducted for the Varennes Islands (Panasuk 1987) and the Contrecoeur Islands (Davies and Watson, 1999).

However, a commensurate understanding of climatic conditions (wind, discharge, ice) and human activities (boating, shipping, shore activities) on erosion is still lacking. The relative contribution of these factors must be established in order to identify which human activities can be managed to control/reduce flooding and erosion in the lakes and river.

In the U.S., a number of detailed studies have recently been carried out in association with the St. Lawrence - FDR Power Project Relicensing. These studies need to be carefully reviewed to determine their relevance and usefulness to this process. Wherever possible, efforts will be made to draw upon existing knowledge.

6.3.3

New Study Scope, Data Collection Needs and Evaluation Methods

To properly examine the criteria contained in the Order of Approval for the regulation of water levels and flows in the Lake Ontario-St. Lawrence River system and to respond to potential climate change/variability, it is necessary to be able to provide accurate erosion and flood predictions and be capable of predicting regional sediment transport and sediment budgets. To do this, flood and erosion prediction models need to be developed which account for shoreline geology, structures, sand supply, and environmental conditions such as still water levels, wind and ship waves, currents, vegetation, and ice cover. Various components to the modelling process will have to include the development of a detailed coastal zone database and/or digital terrain model; the development of relationships between still water level and wave propagation on shorelines for various hydraulic scenarios and vegetation distribution/state of growth; the quantification of the relative amounts of energy produced by currents, natural waves, commercial navigation and recreational boating waves; the determination of associated recession rates; wave runup, flooding and hydrodynamic predictions; longshore sand transport and sediment budget analysis; sandy and cohesive shore erosion predictions; predictions of the transport of eroded material from shorelines and potential redeposition/resuspension along shores and/or riverbed; and slope stability assessments. All of these components must be integrated and linked to translate input data into flood, erosion and low water level impact predictions.

The U.S. Army Corps of Engineers has already initiated development of a modeling and data management system for the U.S. shorelines of Lakes Michigan, Ontario, Erie and the St. Lawrence and Niagara River. No such work has been initiated on the Canadian side of Lake Ontario or the Niagara Rivers. Some models are being developed by the Canadian Coast Guard in partnership with Environment Canada and the Canadian Hydraulics Centre as pilot studies for the riverine environments of the St. Lawrence River.

Key data inputs to the various analytic procedures for Canada and the U.S. include:

• Topographic and bathymetric data (Digital elevation model)
• Coastal Zone Database and/or Digital Terrain Model
• shoreline geomorphology
• shore protection quality and quantity
• nearshore/sub-aqueous
• Planimetric features (e.g., roads, buildings)
• Digital orthophotos
• Land use and land use trends
• Property values, facilities and infrastructure elements
• Surficial and subsurface information for the lake/river bed
• Wave runup and flooding
• Sediment budget
• Historic estimates of recession rates
• Bluff height, slope, and the frequency of gullies
• Historic blufflines and shorelines
• Ice coverage and ice jams
• Ship wave climates
• Vegetation
• Hydrodynamic variables

In addition, point data are required which include:

• Ground level photos
• Sediment characteristics
• Borehole logs
• Dredging records
• Beach nourishment history
• Nearshore profiles
• Measured, hindcasted, and forecasted deepwater and transformed wave data
• Measured and forecasted water level data

As is evident, the analysis requirements are very data intensive. The following outlines the steps required to fully develop, populate and run a coastal flood and erosion prediction system so that accurate predictions of damage as a result of flooding, erosion and the impacts of changes in water level regimes can be made.

Step 1: Coastal Zone Database and/or Digital Terrain Model

A shoreline classification was developed during the Levels Reference Study in the early 1990s and revised and improved for Lake Michigan and the U.S. shores of Lake Erie and Ontario through the Lake Michigan Potential Damage Survey and Lower Great Lakes Erosion Study. The original classification was developed on a reach by reach basis. Work needs to be done to update this classification scheme for the Canadian shoreline of Lake Ontario, St. Lawrence and Niagara River to an appropriate resolution (e.g. 1x1 km or finer). The classification needs to be revised to improve the detail of information and provide more confidence in the nearshore geology and to add emergent and aquatic vegetation. This task includes reviewing more current information (e.g. erosion classification developed for the St. Lawrence River - Argus for EC, 1996), and holding a workshop with coastal experts. Data requirements include aerial photos (less than 1:10,000), nearshore profiles, bathymetric charts, topographic maps, video of the shoreline, any inventory of shore structures and mapping of bluff stratigraphy. The existing Geographic Information System (GIS) database system will be updated with the revised information. {Note: Required topographic and bathymetric data is addressed in section 4.2, Common Data Needs}

Step 2: Define Driving Forces for Erosion (Historic and Future)

This task has two purposes, the first is to quantify the relative amounts of energy contributing to the erosion process (including the effects of water levels, natural and boat-related waves, ice and vegetation) to provide model calibration and the second is to establish conditions for future scenarios. The task includes the development of water levels as influenced by river flows, ice effects and wind generated surge. Currents and ice cover and ice jams must be assessed and included in the modelling process where appropriate. Nearshore wind waves must be predicted. This can be done by using hindcast deepwater wave (hourly), water level (hourly where possible) and ice data. There is also a need for the development of a method for estimating ship wave climates on the St. Lawrence River. Previous studies by the Canadian Coast Guard and Public Works Government Services Canada to estimate ship wave climates will be reviewed along with more recent models being developed by the Canadian Coast Guard in partnership with Environment Canada and the Canadian Hydraulics Centre.

Step 3: Determine Recession Rates (Includes aerial photography)

To determine consistent recession rates for the shore, the current shoreline taken from aerial photos and/or airborne laser profiling systems should be compared with a historical shoreline. Historic aerial photos exist for the entire Lake Ontario - St. Lawrence River shoreline. The entire shoreline needs to be flown again to provide a recent shoreline coverage. This aerial photography/imagery coverage could also assist with the shoreline classification outlined above and in determining current land use and land use trends, and to develop recession rates representing different historic combinations of lake and river levels, natural and boat-related waves, ice and vegetation coverages. Airborne data can also be used for the evaluation of wetland impacts. The costs for flying the shoreline are covered in 4.2. The development of the Digital Elevation Model, the defining of historic and current bluff lines and the estimation of recession rates through the modelling process are considered here.

The historical recession rate database developed in the Levels Reference Study (Working Committee2, 1993) and based on existing literature, will be reviewed, updated and used to identify areas requiring additional recession rate development.

It may be that the shoreline classification completed in Step 1 can be used to identify those areas where recession is more likely. In a cost saving effort, these areas could be concentrated on. If accessing new shoreline data is not possible, older information may be utilized to help determine recession rates. This will, however, not provide a definition of the modern conditions, nor would it result in a consistent base for analysis.

Step 4: Determine Land Use/Zoning and Land Use/Zoning Trends:

1. Land Use and Land Use Trends:

Using existing land use maps, documentation, and aerial photographs of the shoreline, land use types will be determined at an appropriate resolution along the shoreline. Building on findings from the Levels Reference study and utilizing historic and current aerial photographs, meeting with planning officials and resource groups and reviewing planning documents, land use and land use trends will be determined along the shoreline and input to a digital database.

2. Hazard Zones:

Current municipal flood and erosion zoning requirements and other management practices in force will be documented and added to the GIS coastal zone database along with any plans for zoning changes. This data will be gathered at the same time as the land use data. The number of properties within zoned areas will be determined using existing digital basemaps and an assessment of the effectiveness of the zoning requirements will be made.

Step 5: Monitoring and Analysis of Test Sites on Lake Ontario and the St. Lawrence River to Support Numerical Model Investigations

To test/calibrate the flooding, erosion, sediment transport, and economic models, detailed site studies need be carried out. Detailed information will be complied for the study sites at or less than 1 km in length, including the shoreline geomorphology and subaqueous geology, shoreline bathymetry, topography, bluff heights and slope, sediment characteristics and distribution, property values etc.

Depending upon the characteristics of the site and the availability of previously collected data, the tasks required at the test sites may include:

• complete physical model erodibility tests of undisturbed samples of cohesive sediments
• estimate detailed recession rates for the study sites (i.e. for several snapshots in time) through development of digital orthophotos within the GIS
• complete hydrodynamic measurements, hydrographic surveys, and jet probing to determine sand thickness (reoccupying historic lines wherever possible) and grain size
• analysis of beach and nearshore sediments and geologic stratigraphy
• review role of bluff stability issues at sites with bluffs to determine lakewide methodology for considering the impact of bluff failure cycle on error band associated with predicted bluff positions
• complete numerical modeling of erosion to test capability of the model to predict (hindcast) erosion at each of the sites and along longer reaches over several kilometres or miles (considering longshore and cross-shore transport) and make any necessary modifications
• determine aquatic plant evaluations for various combined water levels and temporal and spatial variations
• consider impacts of shore protection (with different ages and design life) on future erosion rates
• near shore wave climatology for various water levels and periods of the year

Step 6: Lakewide-Riverwide Implementation - GIS

This task requires establishing the linkages between the modelling tools and a Geographic Information System (GIS). This will allow lakewide/riverwide implementation of the models. The task consists of setting up the system with the required GIS data layers (elevation data including topography and bathymetry, recent and historic bluff lines, digital land use data and planimetrics, orthophotos, and geological data).

Although there may be alternatives to lakewide-riverwide implementation of the system, any alternatives would require careful review in order to be fully justified and defensible.

Step 7: Application for Future Scenarios

1. Flooding

Assess flooding potential for a range of conditions considering static lake level, surge, wave runup and overtopping at an appropriate level of resolution. On the St. Lawrence River factors will include a variety of conditions for the Ottawa River and local inflows and ice jams.

2. Erosion

Sediment budget information is required for cohesive and sandy shorelines in order to link the coastal analysis per site to a lakewide basis. Sediment budget analysis includes considering the impact of changing sand cover due to both natural and human influences on past and future erosion rates. This is a key issue to consider in order to assess future "what if" scenarios. A preliminary review of the impact of harbors and related structures on sand bypassing must be conducted.

Recession rates will be developed and analyzed on a lakewide-riverwide basis using the historic and recent bluffs through a comparison of predicted (hindcast) and determined actual recession rates. Any necessary adjustments will be made to reasonably represent actual rates. The coastal erosion models will then be applied to determine recession rates for future water level scenarios including climate change scenarios. Transport of eroded material and potential redeposition/resuspension along shoreline and/or riverbed will be simulated for expected future conditions.

3. Low Water Impacts

Very little information exists on the implications of low water to the coastal system of the Great Lakes - St. Lawrence River system. The modelling tools developed will be applied to consider the full range of possible future level scenarios. Determining the implications of lower water levels is a key component to this study, especially in consideration of possible climate change scenarios.

Step 8: Damage Assessment

Once predictions of flooding, erosion and low water impacts can be made, an assessment of total potential damages will have to be determined. It is generally accepted that existing stage-damage curve relationships are no longer adequate and must therefore be updated, or, a new impact assessment methodology developed and applied. Site studies, damage curves, land use information, existing digital data on structures, or some combination of these will be used.

6.3.4

Implications of Climate, Demographic and Other Changes

Isostatic rebound or the vertical uplifting of the earth's surface after the removal of the tremendous weight of glaciers, has occurred since glacial time. On Lake Ontario, the eastern outlet end is rising with respect to the western inlet end at a rate of about 17 centimetres per century (EC, 1993). The result is that the shore at the western end of the lake is experiencing a gradual increase in water level. In addition, there may be tectonic warping of the basin causing differential subsidence. This has implications for Great Lakes datum and to the regulation plan which bases its criteria on datum levels. Isostatic rebound should be considered in any revised regulation plans.

The shoreline is a desirable place to live. The demographics of the shoreline continue to change particularly on Lake Ontario where population levels continue to rise. Land use trends, land use zoning and other management techniques used along the shoreline will be addressed in the proposed studies. Considering this desirability, and as was recommended in the Levels Reference Study, prudent coastal management practices are encouraged at local, as well as higher, agency levels.

Climate change scenarios and the potential impacts to flooding, erosion, sediment transport and sediment budgets will be evaluated.

6.3.5

Optimal Conditions

Erosion: The Levels Reference Study (Working Committee 2, 1993) made some attempt to determine whether a reduction in the range of lake levels would significantly effect recession rates. Preliminary results did conclude that about 45% of the Lake Ontario shoreline and as much as 63% of the St. Lawrence River shoreline would experience some reduction in recession as a result of a 50% reduction on water level range. However, these estimates are quite coarse and reflect only a very significant reduction in water level range which would never be operationally achievable, nor desirable from an environmental view point. An optimum range was not determined, but could be estimated using the described refined coastal data base and flooding and erosion analysis system.

Flooding: A reduction in maximum Lake Ontario and St. Lawrence River levels - particularly during the spring and fall storm season and the Ottawa River freshet - will reduce the probability of flooding. Maximum and minimum levels have been established in the current Criteria for Lake Ontario (Criteria (h), (i) and (j)). The current criteria do not provide maximum and minimum levels for the St. Lawrence River, however, condition (i), which contains the criteria, does state that the project works shall be operated "in such a manner as to provide no less protection for navigation and riparian interests downstream than would have occurred under pre-project conditions and with supplies of the past as adjusted, defined in criterion (a)"… This has been interpreted and applied by the board and the Commission over the past 40 years as establishing specific limits, in terms of levels and flows, for supplies as they occurred in nature.

6.3.6

Study Organization, Costs and Schedule

The agencies that could undertake these evaluations are listed in Annex 1. The following outlines estimated costs to undertake the proposed methodology for predicting flood and erosion damages to Lake Ontario - St. Lawrence River shoreline interests.

Table 4a. Time and Cost Estimates - Coastal Zone Studies (U.S. $K)

Table 4b. Time and Cost Estimates - Coastal Zone Studies (Cdn. $K)

6.4	Commercial Navigation Interests

Commercial navigation, for the purpose of this study, includes vessel operations associated with the movement of commercial cargoes, commercial fishing, tug and barge operations, cruise/tour operations, ship construction/repair operations and government vessel operations.

From a quick review of the needs and nature of commercial navigation in the Lake Ontario-St. Lawrence River system, it is recognized that there are three distinct sections :

1. The commercial traffic on Lake Ontario which is affected to a limited degree by water level fluctuations. The level fluctuations on the lake are relatively long term and in small increments and the Seaway/Great Lakes traffic is limited to Seaway draft (U.S. & Canada).
2. The traffic within the Seaway limits; captive traffic, influenced more by Lake Ontario outflows and river level fluctuations than traffic on Lake Ontario (U.S. & Canada).
3. The deep sea traffic to and from Montreal to the Atlantic. This sector includes mainly sea-going traffic. As well, the ship channel to Montreal is open year-round and is impacted by water level fluctuations, a factor of Lake Ontario outflow and flow from the Ottawa River. Ice in the St. Lawrence River can also affect the levels in the area.

This section follows the approach of splitting the area and activity to be studied into three zones.

6.2	Relationship To Water Level Fluctuations

b) Lake Ontario

Changing water levels on Lake Ontario affects two major transportation interests: vessel owners and port/dock operators. Vessel owners affected would include all U.S., Canadian and foreign vessel owners whose vessels would have to use Lake Ontario in their commodity movement. Port/dock operators affected are those (U.S. or Canadian) located on Lake Ontario. These interest groups may also be associated with related transportation interests that comprise part of the regional transportation infrastructure, including truck, rail and barge systems. The major concern of these two most directly affected interest groups is to avoid adverse changes in expected long-term levels of net commercial income of shippers and ports.

Related issues such as marginal changes in transport times, additions or deletions to the commercial navigation fleet required to move the expected commodity volumes, change in the level of use of locks, channels or terminals resulting from impacts of measures to deal with water level changes are additional impacts of water level changes.

b) St. Lawrence River - Seaway

The St. Lawrence River from just above Montreal to Kingston can be divided into three sections with distinct hydraulic characteristics. The water level for the upper section of the St. Lawrence River from Kingston to Moses-Saunders Power Dam near Massena/Cornwall is primarily influenced by water levels on Lake Ontario and the outflow through the power dam, and may also be influenced by the gates open settings at the Iroquois dam. The level in the middle section from Massena/Cornwall to Beauharnois Canal is affected primarily by the flow from upstream (the Moses-Saunders plant) and releases at the Beauharnois-Cedars complex. The downstream section of the St. Lawrence River from Beauharnois to St. Lambert is further affected by the outflow from the Ottawa River which enters Lake St. Louis upstream of South Shore Canal.

Two factors are critical to safe and efficient navigation; the available depth of water, and the currents created by water flow. Within each of these sections of the St. Lawrence, navigation conditions are impacted by both the absolute water levels, and the flow rates at any moment. Above Cornwall, depths in the various sections of the river are largely a function of the level of Lake Ontario, and the volume released. Flow rate, and the currents generated in various sections of the river, are in turn dependent on the slope of the river, which is affected by the open setting of the various control structures, at Iroquois, Cornwall/Massena, & Beauharnois-Cedars. Higher flow rates require greater slopes on the river, and may actually result in lowering water levels on Lake St. Lawrence just above Cornwall/Massena, even when Lake Ontario levels may be high. Low flow rates, which would often be the case at periods of low Lake Ontario levels, may actually produce higher than normal depths on Lake St. Lawrence, though the Port Montreal would be at low levels. Thus, there is a complex relationship in these reaches of the St. Lawrence River between Lake Ontario levels and flows and the water depths and currents with which shipping must contend.

The other major factor affecting the water level fluctuation, particularly in Lakes Ontario, St. Lawrence, St. Francis and St. Louis is the speed and direction of prevailing wind. For instance, a strong and steady easterly or northeasterly wind during the fall when the river level is normally low is of particular concern in Lake St. Lawrence because the water level could easily drop up to 20-25 cm.

The Seaway navigation channel was originally designed and constructed to handle a maximum flow of 8800 cms (310,000 cfs) without exceeding the maximum ship maneuvering velocity of 1.22 mps (4.0 fps). Water supplies for Lake Ontario for the period 1860-1954 were used in the project design. However, there has been some experience with operations at higher flows at periods of very high Lake Ontario levels. As a practical means of determining the velocity in various reaches of the St. Lawrence River, the water level differentials between gauges are regularly monitored during the high outflow period.

As a result of favorable water level conditions during the certain periods of the year coupled with some subsequent channel dredging and vessel speed reduction, in certain reaches of the St. Lawrence River, the Seaway entities increased the maximum permissible draft from 7.92m to 8.00m in 1992. The annual benefit to the shipping industry for this draft increase has been estimated to be $3.0 million (Cdn.). In addition, the Seaway navigation season is now routinely extended beyond what was expected, both at the opening of navigation, in the latter part of March and at the closing of navigation in the latter part of December. This requires careful coordination with other interests, particularly during the critical period of ice formation each year.

c) St. Lawrence River - Port of Montreal & Downstream

The deep sea traffic arriving and departing the Port of Montreal and other ports on the St. Lawrence River downstream of Montreal, is affected primarily by the following factors :

1. the outflow from Lake Ontario
2. the outflow from the Ottawa River, and
3. local tributary flows.

In the open-water season, the main factors affecting water level fluctuations are the outflow from Lake Ontario and the Ottawa River. The Ottawa River outflows are regulated to a minor degree so that the regulation of that river does not play a significant role in the water level fluctuations in the Montreal area, as the primary intent in that case is to provide short-term storage of the upstream reservoirs; the river flows are essentially determined by the basin supplies. The river flow, however, can fluctuate greatly, influenced by the freshet in the spring and local basin precipitation. Therefore, the primary focus in this instance will be on the water level fluctuations caused by flow changes from Lake Ontario, but including consideration of the impact of Ottawa River flows. As a rule of thumb, a change in the Lake Ontario outflow of 1,000 m³/s will result in approximately 40 cm water level fluctuation in the Port of Montreal.

In the winter, the traffic to and from the Port of Montreal continues, supported by ice cover management, including ice booms and ice breaking operations.

The Port of Montreal, and others such as Sorel, Trois-Rivières and Bécancour are inland river ports and, therefore, the traffic to these ports must make use of the full depth available at the time of their voyage. Additionally, the deep sea traffic in the St. Lawrence River ports does have some seasonality which must be taken into consideration.

The levels in the Port of Montreal generally react to Lake Ontario outflow changes within 18 to 24 hours. This will have to be better understood, particularly given the micro-management strategies frequently being adopted by the Board in the last few years, as well as when operating under Criterion (k) conditions or other critical situations.

Finally, the operations of Hydro Quebec at the Beauharnois/Cedar facilities can impact the water levels in Montreal. While the storage capacity on Lake St. Francis is rather limited, again, given micro-management of recent years, there could be instances where levels in the Port would be affected significantly. This situation needs to be better defined.

Any Criteria additions or revisions resulting in extreme low/high Lake Ontario outflows could impact significantly on the Port of Montreal area and downstream. The impacts must be analysed and the need for appropriate measures will be assessed/determined.

The traffic to the Port of Montreal depends extensively on adequate foreknowledge of the water level conditions. A significant portion of the traffic comes from overseas destinations and requires loading and schedule planning to ensure that, on arrival, the vessels will have adequate water depth to accommodate their passage safely. The Port of Montreal in particular depends significantly on one-to-four-week forecasts provided by the Canadian Coast Guard to define the maximum allowable drafts to which large deep draft ships may load. These large vessels loaded to the anticipated capacity of the waterways can suffer significant disruption, and consequently economic losses, as a result of rapid and unexpected fluctuations in the water levels. As a minimum they may encounter delays in their arrival schedules, but more likely they could be required to offload in other ports such as Halifax, Sorel or Quebec. The negative impact of inadequate knowledge of the water level conditions therefore, is not only on the performance of shipping lines but also on the Port. The Port of Montreal is currently completing a major channel deepening project which will provide an additional one foot depth for traffic to and from the Port. Stability and predictability of the water levels is vital to the commercial shipping activity in this major international waterway and must be managed as best as possible with the necessary information and technical tools.

6.4.2

Past Studies

a) Lake Ontario

A wide range of studies have dealt with Lake Ontario commercial navigation interests, either as a component of a larger study, or as a study of Lake Ontario alone. A number of these studies are listed below.

1. "Levels Reference Study, Great Lakes-St. Lawrence River Basin", submitted to the International Joint Commission by the Levels Reference Study Board, 1993.
2. Task Group 4, Working Committee 3, "Commercial Navigation Work Group Report" , Levels Reference Study, International Joint Commission, July 1993.
3. "The Economic Impacts Of The Great Lakes/Saint Lawrence Seaway System", prepared for the St. Lawrence Seaway Development Corporation by Martin O'Connell Associates, Sept. 1992.
4. "The Great Lakes, An Environmental Atlas and Resource Book", by Environment Canada, U.S.E.P.A., Brock University, Northwestern University, 1987.
5. "The Economic Impact Study of Major Marine Initiatives", prepared for the Canadian Coast Guard by Hickling Corporation and Booz Allen Associates, December 1996.

b) St. Lawrence River - Seaway

There are numerous past studies and/or reports related to the river hydraulics and its effects to the commercial navigation.

The Power Entities maintain seven (7) water level gages, namely, Kingston, Ogdensburg, Cardinal, Iroquois, Morrisburg, Long Sault and Saunders along the upper St. Lawrence River. In addition, there are CHS gages in Summerstown in Lake St. Francis and Pointe Claire in Lake St. Louis. Alert and minimum elevations for commercial navigation at each gage locations are fully described in a report entitled;

1. "A Compendium on Critical Water Level Elevations in the Lake Ontario-St. Lawrence River System" by the International St. Lawrence River Working Committee, December 31, 1994.

In addition, there are a number of other reports available, including;

2. "St. Lawrence River Direction and Velocity Measurements" Report#1, #2 and #3 by SLSDC, 1976/77, 1978, 1982 and by SLSMC.
3. "St. Lawrence River Discharge Measurements" by COE, Detroit District, 1976 and 1987
4. "Vessel Speed and Wave Studies (7 volumes)" by St. Lawrence Seaway Authority, 1970-1974
5. Sounding/Sweeping results by SLSMC/SLSDC
6. Annual Seaway Traffic Reports (1959-1998)

Some of the more important/recent past studies in which the subject of commercial navigation has been addressed are :

1. Montreal Harbour Satisfaction Curves. Ed Eryuzlu, February 25, 1994. Unpublished.
2. A report on 1998 water levels of the Great Lakes and the St. Lawrence River. Environment Canada, Cornwall. January 1999.
3. "A Compendium on Critical Water level Elevations in the Lake Ontario-St. Lawrence River System" dated December 31, 1994 (as above).
4. "The Economic Impact Study of Major Marine Initiatives", prepared for the Canadian Coast Guard by Hickling Corporation and Booz Allen Associates, December 1996.
5. Canadian Waterways National Manoeuvring Guidelines : Channel Design Parameters. Waterways Development, Manrine Navigation Services. November 1998.
6. Stage Discharge Relationships in the reach of the St. Lawrence River, Montreal to Trois-Rivières. Department of Transport, March 1968.

6.4.3

New Study Scope, Data Collection Needs, and Evaluation Methods

To the extent feasible, compatible methodology will be used in all three zones of the system.

The studies discussed below in detail will naturally take into account other interests, recognizing however, that all other identified interests will be covered in the Plan of Study.

1. Lake Ontario

The scope of work relating to commercial navigation on Lake Ontario (U.S. and Canadian) will rely heavily on existing information with respect to Lake Ontario port infrastructure, vessels used in moving commercial tonnage (U.S., Canadian and Foreign vessels) on Lake Ontario, historical Lake Ontario tonnage levels, origin/destination routes for lake Ontario ports, vessel operating characteristics, vessel operating limitations (Coast Guard Load Line Limits, maximum vessel operating draft on the Seaway system, etc.).

In addition to the material already available additional data will be required to allow assessment of the impacts of various flow regimes.

1. Information on the physical commercial navigation system needs to be collected/updated (ports, channels, locks). Information on all commercial ports involved as origin or destination points for waterborne commerce using Lake Ontario will need to be developed. Port data would include controlling depths, dredging needs, dock locations, depth at dock and loading capabilities/rates, etc. The maintained depths and widths of all connecting channels/locks on the various trade routes will also be needed, as these are effectively restricting depths/widths for all ships in the system.
2. Meetings/interviews/surveys will be needed with the vessel operators and port/dock operators to identify key linkages between changes in water levels and resulting major impacts on their operations. These data will quantify the impact of changing water levels/flows on their operations.
3. Sources of data, needed for the characterization and development of an evaluation, model will need to be identified. A range of potential data sources will be contacted. A source of information on the currently maintained channel depths at U.S. ports would be the U.S. Army Corps of Engineers. Sources of data on maintained depths at various port docks would be from the dock owners themselves, "Greenwoods Guide To Great Lakes Shipping" or the United States Coast Pilot 6. Again, parallel data sources will be needed for all Canadian ports, channels and docks.
4. Major commodity traffic and trade routes will need to be identified. Vessel movements for a representative season will need to be collected for all vessels transiting Lake Ontario. The level of detail needed on waterborne commerce movements would include the vessel name, the commodity carried, the number of tons of commodity carried, the origin port, the destination port, the origin port date and the destination port date. Potential sources of these waterborne commerce movements would be the U.S. Waterborne Commerce Statistics Center in New Orleans, La. And Statistics Canada.
5. Vessel characteristics such as length, width, maximum vessel draft by time of season, tons of various commodities (iron ore, coal grain) carried at mid summer draft, tons per inch immersion factors, presence of bow or stern thrusters and type of vessel power plant would be needed.
6. Information on port infrastructure, dock locations and maintained channel depths at the various docks would be needed to develop port/dock impacts for fluctuating water levels

The methodology for evaluation will be based on existing commercial navigation transportation cost models and regional impact models. A Levels Impacts
Transportation Model will be developed which will concentrate on identifying the change in net commercial income of shippers and port/dock operators between an established base condition and alternative water level regimes. One component of the model will concentrate on developing changes in vessel operating costs due to changing water levels. The second component would concentrate on developing changes in income/utilization to port/dock operators due to changing water levels.

2. St. Lawrence River - Seaway

In order to allow for review of the potential to alter, or add to, the existing criteria governing operation of the present works, and to understand the effects on commercial navigation, additional information will need to be developed, and a methodology designed to allow assessment of the impact of various flow regimes,

1. Data needs to be developed to better understand the relationships between water depths and flows in the St. Lawrence from Lake Ontario to Montreal, and the currents that are created within the shipping channels, particularly during high flow periods. Time series of levels and currents at various key locations (including those already equipped with gauges) need to be developed, over a multi-year period, so as to encompass all seasons in which commercial navigation operates, including periods of high flow conditions (over at least two, and preferably 3 years). This program will be integrated with the work to be undertaken in Section 7.1, to develop a 2-D hydrodynamic model for the Kingston to Cornwall/ Massena area.
2. Hydrodynamic phenomena, such as squat and bank suction, are generally well understood, but additional work is required to fully appreciate the impact of such factors on ships maneuvering in these specific channels, particularly during low water periods. Literature review will be undertaken to determine if similar situations elsewhere have been evaluated in the necessary depth, but it may also be necessary to instrument and record the motions of a number of typical ships which are regular traders through this area. The database thus obtained will allow evaluation of adequacy of present or proposed side and bottom clearances during transit.
3. Maneuvering characteristics of modern ships have changed considerably since the Seaway system first opened, and considerable experience has also been gained in control of ships passing through these channels. Officers and pilots of ships using the channels on a regular basis will be surveyed to determine their views with respect to any difficulties caused by the present range of depths, and of currents, experienced over the past years of operation, including both high levels and flow and low levels and flow conditions.

Using the data thus gathered, as well as economic indicators such as efficiencies per inch of immersion and timeliness of cargo delivery, a methodology similar to the Lake Ontario model will then be developed to allow for consideration of the impact on levels and flows in these sections of the St. Lawrence River as a result of the introduction of new criteria or the amendment of existing criteria. This analysis will include specific consideration of (as a minimum);

• The examination of the potential to raise or lower alert and minimum navigation elevations by varying incremental amounts along the entire St. Lawrence River under the existing channel conditions, and the related impacts on all interests,
• Impact to navigation in Lakes St. Francis and St. Louis reaches of the St. Lawrence River under the extreme low outflow conditions, including the potential for amended Seaway operating procedures for the management of such situations, and the resulting impact on industry.
• Impact to commercial navigation in the upper St. Lawrence River and South Cornwall Channel under the extreme high outflow conditions. Remedial works/measures including physical improvements to increase channel capacity, required to maintain acceptable commercial navigation conditions (i.e. current velocity and minimum water level) will not be considered at this stage, but amended Seaway operating procedures may be considered.

Rather than carrying out such evaluations for all possible combinations of levels and flows, the final analysis of impacts should await the development of proposed criteria amendments or proposed new criteria, which can then be tested and evaluated to determine the impact on Seaway operations. Therefore, the data collection and development of an analysis framework will proceed within the first three years, but testing of possible new or amended criteria will be carried out, once these have been proposed, in the fifth year of the overall review.

3. St. Lawrence River - Port of Montreal & Downstream

In the case of the St. Lawrence River deep-draft traffic, there is a need to address:

1. The seasonal patterns of deep-draft traffic to the Port of Montreal for the proper assessment of revisions to criteria and their impact on the Port of Montreal. The traffic patterns in the Port have changed significantly in comparison to that at the completion of the project;
2. The volume of the traffic that is impacted by limited water depths, i.e. there is no need to gather data on all commercial traffic to the port but traffic that requires, say 25' draft and more;
3. Approximations of lost business resulting from inability to make full use of loading capacity to/from the St. Lawrence Ports, and approximations of added benefit experienced when levels above datum and mean levels are available.
4. The effects of short-term Lake Ontario outflow changes on levels in the Port of Montreal area.
5. The effects of Hydro Quebec operations at Beauharnois-Cedars on levels in the Port of Montreal, in relation too short-term water storage on Lake St. Francis.
6. The impact of winter operations of Lake Ontario regulations on the water levels in the St. Lawrence River in the Montreal area and downstream. This will include risk of flooding of the Port facilities and surrounding areas, including downstream.
7. Means to reduce the risk of extremely high Lake Ontario outflows impacting the Port of Montreal operations and downstream areas.
8. Options and means to reduce the impact in the Port of Montreal during extreme low flows from Lake Ontario.
9. The limitations/constraints impacting requirements of Port of Montreal and Seaway traffic, and potentials for constraints resulting from operations of the Seaway.

Studies and appropriate data and information on these issues will be essential not only in minimizing possible adverse impacts in the Port of Montreal area but also may facilitate better management of Lake Ontario outflow fluctuations, including any changes in the current operational criteria.

An evaluation methodology compatible with that developed for the upper portion of the system will be developed which allows for consideration of the impacts on Port of Montreal and downstream commercial navigation activity, which might be caused by new criteria, or the amending of existing criteria.

6.4.4

Implications of Climate, Demographic and Other Changes

Changes in climate (global warming) or demographics (population location, population increases) can have impacts on the levels and flows of the Great Lakes - St. Lawrence River system.

Most advanced computer models currently predict that water supplies to the Great Lakes and St. Lawrence River will be reduced over the next century(refer to the Section 4.3).

The water supply estimations provided by these climate models need to be looked at as a plausible range of conditions that could prevail in the future. Whatever future scenarios are utilized in this study to address climate change will be evaluated for their impact on Lake Ontario, the Seaway, and the Port of Montreal operations using the analytical approaches described herein.

6.4.5

Optimal Conditions

1. Lake Ontario

The Levels-Impacts Transportation Model could be developed to provide outputs that would indicate various optimal conditions from the perspective of commercial navigation users. For example outputs could be developed that would indicate what percent of commercial navigation traffic would have no impacts from various water level regimes (i.e. if Lake Ontario water levels were maintained at chart datum, what percent of the commercial navigation fleet servicing Lake Ontario would have excess carrying capacity.). Alternatively, the model could be configured to determine what is the maximum water column that could be utilized by vessels carrying various commodities. This maximum water column could then be converted to a lake level. Other optimal indicators for commercial navigation could be developed as they become identified in the study process.

2. St. Lawrence River - Seaway

Generally, constant water levels near the maximum annual mean would give the most satisfactory result in terms of the trade-offs between levels and currents, but this is an overly simplistic approach, as there are also seasonal variations impacting significantly on water levels in Lake St. Lawrence, Lac St. Louis and Lake St. Francis. Detail on the optimal conditions in the St. Lawrence River sections from the perspective of commercial navigation users operating in the Seaway system will be described by the proposed subcommittee Study Team, within the first year of the project, so as to provide necessary guidance to other working committees.

3. St. Lawrence River - Port of Montreal & Downstream

In general terms, high water levels tend to favor the use of deeper draft, and hence more economic vessel loads. The Port of Montreal has generally been able to rely on water levels that are at least at or above chart datum, and there have been significant periods in which the water levels over the period of regulation have allowed for several feet additional draft for large ships, while maintaining safe under keel clearance limits. The Port of Montreal market their services aggressively throughout much of the world, with one of their strongest selling points being consistent and reliable service, year round. Therefore, the predictability of water levels in the St. Lawrence River becomes as important as the actual level. Considerable effort is put into forecasting water levels for days and even weeks in advance, but if the actual levels encountered upon arrival are substantially below those expected, large container ships may be to diverted to Halifax or make an extra stop at Sorel or Quebec City to partially offload their cargo. This may add significantly to the costs of the overall shipping operation and makes the St. Lawrence River ports less attractive, so forecasting accuracy is essential.

6.4.6

Study Organization, Costs and Schedule

The three study teams (or representatives), in each of the sections a), b) and c) below, will come together as a single binational Commercial Navigation Study Team to consider all aspects of the work.

While there are normal differences in the nature of the commercial navigation activities in the three zones in the system, there is a need to provide compatible outputs of the studies. This will include identification of the interests that depend on commercial navigation on the Lake Ontario - St. Lawrence River system and how they would be affected under various scenarios. Therefore, the studies will not be limited to economics, but will include other types of outputs where appropriate.

1. Lake Ontario

Work will be overseen by a binational Study Team. Representatives for this section will include the Corps of Engineers, The Canadian Coast Guard, Transport Canada, one U.S. and one Canadian port manager, and the Great Lakes Pilotage groups. Contracted resources may be used in some cases such as in data collection, but it is envisaged that the Corps of Engineers would carry out the main Transportation Model development, with input from Canadian authorities represented on the steering committee. Table 5 a and b give estimates of the cost associated with evaluating criteria in terms of commercial navigation interests located at Lake Ontario ports.

Table 5a. Time & Cost Estimate - Commercial Navigation, Lake Ontario (U.S. $K)

Table 5b. Time & Cost Estimate - Commercial Navigation, Lake Ontario (Cdn. $K)

2. St. Lawrence River - Seaway

The identified work will be overseen by the binational Study Team. Representatives for this section will include from the Seaway Entities, the U.S. Army Corps of Engineers, the Canadian Coast Guard, local Pilotage representatives, and the Environment Canada Great Lakes Regulation office in Cornwall. Actual development of the required data including conduct of tests and measurements, can be conducted through private sector contractors.

Estimated Cost:

Table 5c. Time and Cost Estimate-Commercial Navigation, St. Lawrence Seaway

3. St. Lawrence River - Port of Montreal & Downstream

As with the St. Lawrence and Lake Ontario reaches, a binational Study Team will oversee the work. Representatives for this section will include the Port of Montreal, the Canadian Coast Guard, Environment Canada, and the Laurentian Pilotage Authority, and the U.S. Army Corps of Engineers. The identified work (listed in Section 6.4.3 c) can best be performed by a private consultant. This may be combined with all or parts of other works identified under this Study Plan. As well, another important assumption is that the evaluations of the interests will not be done in terms of purely economic values; since that approach has not led to meaningful results in the past. Finally, the work/studies identified here are designed to help the principle objective of facilitating criteria review, including the potential of new criteria being introduced.

The costs estimated are:

Table 5d. Time and Cost Estimate-Commercial Navigation, Montreal & Downstream

Table 5e. Total Time and Cost Estimates for Commercial Navigation

6.5	Hydroelectric Power Interests

6.5.1

Relationship to Water Level Fluctuations

1. Power from the River

Although water level changes effect hydropower generation, power generated depends on several factors - head, flow, continuity, and efficiency.

• Head is the vertical distance that water falls across the turbines to create power. Higher head, (i.e. the greater distance for the water to fall), means higher power.
• Flow is the amount of water that falls through the turbines, which converts potential energy to electrical energy.
• Continuity can be described as the reliability of the river flow.
• Efficiency is the percentage of the potential energy of the water transformed to electrical energy. Given the history of the other three values above, turbines at hydropower stations are designed to minimize the waste of energy and are carefully shaped for high efficiency.

2. Lake Ontario - St. Lawrence River Flow Relationships

In the Lake Ontario - St. Lawrence River system the following relationships must be understood as they relate to Lake Ontario water levels as explained below.

• Relatively higher water levels on Lake Ontario means relatively higher flows as directed by the regulation plan. This translates into more electricity generated. However, as the flow increases at the power stations, the headwater level (water elevation at the upstream side of the powerhouses) must decrease since the slope from the lake to the powerhouses will increase. At the same time the tailwater (water elevation at the downstream side of the powerhouse) increases. Effectively, this lowers the head for which to generate electricity.
• Relatively lower water levels on Lake Ontario means relatively lower flows as directed by the regulation plan. This translates into less electricity generated. However, as the flow decreases at the power stations, the headwater increases. At the same time the tailwater decreases. Effectively, this increases the head.
• When flows increase or decrease too much, adverse impacts can result. When flows increase too much, the efficient use of the water is lessened. In fact, a point is reached when an increase in flow does not increase the electricity generated. Higher flow will result in lower efficiency and may result in the powerhouse capacity being exceeded, necessitating spillage. When flows are too low, the total electricity generated is much lower, and cannot meet the demands of the power system. Thus electricity needs to be obtained from other sources at higher prices.

The hydro plant operators understand these changing relationships and attempt to maximize the efficient use of the water from regulation. The fact that the St. Lawrence River is one of the most dependable flowing rivers in the world is due to the huge surface area of the Great Lakes that form the largest series of reservoirs in the world. Any changes in regulation may not have a very large impact on hydropower from year to year. However, the timing of the flow distribution within the year has the greatest effect on impacts to the hydro plant operators. From a power generation standpoint, it is ideal to generate electricity to meet electricity demand. Typically the highest demand has been in the winter months. However, an increase in the summer peak demand over the last decade has moved the summer peak closer to the winter peak.

3. Lake Ontario - St. Lawrence River Ice Management

The regulation plan, controlling Lake Ontario outflows and the economics of power production, depend upon the capability of the critical sections of the international section of the St. Lawrence River to pass the prescribed volume of water through the channels during the winter months. This capability is achieved through the establishment of a smooth and stable ice cover by reducing velocities in the various channel reaches. This in turn requires a reduction in the outflow of Lake Ontario, sacrificing power generation on the short-term, while the ice cover forms, for the sake of greater reliability in power production and regulation on the long-term.

Winter operations are influenced by the hydrologic conditions on the Great Lakes basin and the meteorologic, hydraulic and physical conditions of the International Rapids Section of the river. Experience gained over the period since regulation began, has demonstrated the need to maintain the hydraulic capacity of this section of the river in order to meet the extraordinary requirements placed upon the system by hydrologic supply conditions. Although the Plan 1958-D restricts Lake Ontario mean outflows of no more than 6230 m³/s in January, from 6800 m³/s to 7930 m³/s in February and 7930 m³/s in March, the Board has directed discretionary flows well in excess of these values under favourable ice conditions in order to deal with the high supply conditions that have occurred since regulation began. Although recorded outflows higher than Plan have demonstrated the capacity of the channels, under favourable conditions, the resulting head losses and related inefficiencies remain a serious concern to the hydropower interest, as do the risks to the other users of the system.

6.5.2

Past Studies

"Winter Operations - International Rapids Section of the St. Lawrence River", proceedings of the International Symposium on Ice, International Association of Hydraulic Research. Bartholomew, J., T.E. Wigle, and C.J.R. Lawrie. 1981

"Ice & River Control", Journal of the Power Division American Society of Civil Engineers, Bryce, J.B. November 1968.

"Effects of Peaking and Ponding Within the St. Lawrence Power Project Study Area - Analysis of Historic Data", report to International St. Lawrence River Board of Control, Ontario Hydro and the New York Power Authority. Carson, R.K., and R.P. Metcalfe. March 1994,

"Hydropower Evaluations for the Mainstem Projects in the Great Lakes-St. Lawrence Basin", reports to Working Committee 3, Levels Reference Study. Irvine, Leonard and Taylor. March 1993 and addendum May 1993.

"Regulation of Great Lakes Water Levels, Appendix F, Power", International Joint Commission. 1973.

"Studies to Improve the Regulation of Lake Ontario", status report of the International St. Lawrence River Board of Control Working Committee to the St. Lawrence Board. 1975.

"Update of Studies to Improve the Regulation of Lake Ontario, report to the International Joint Commission", International St. Lawrence River Board of Control. January 1980.

"An Updated Regulation Plan for the Lake Ontario - St. Lawrence River System, report to the International Joint Commission", International St. Lawrence River Board of Control. June 1997. (This report cites preference indicators supporting hydropower interests. These indicators will be further examined in the study).

Levels Reference Study Board, March 1993a, "Hydropower Evaluation for the Mainstream Projects in the Great Lakes - St. Lawrence River Basin", report to Working Committee 3, Existing Regulations, System-Wide Regulation and Crisis Conditions.

6.5.3

New Study Scope, Data Collection Needs, Evaluation Methods

It is felt that sufficient information is available to evaluate the hydropower interest. New studies or additional data collection are not required.

Evaluation of alternate regulation plans or regulation studies will be performed using existing in-house computer models. The models utilize flow, head, and turbine-generator efficiency to simulate power plant operation. The resultant energy production is compared to base case scenarios.

The hydropower entities have developed operational evaluation models. These models could be adapted to evaluate the impact of different regulation alternatives on the hydropower industry. Costs associated to impact evaluation are related to the model set-up, execution and interpretation, and presentation of results.

6.5.4

Implications of Climate Change, Demographics, and Other Changes

Climate change, whether resulting in lower or higher available flow, will impact hydropower production. Rehabilitation of power plants anticipates higher inflow into the 21^st century. As a result, turbine best efficiency flow capacities are being increased 5-10%.

Climate change can not only effect the supply of electricity, but also the demand for electricity. In addition, changing demographics have altered the demand for electricity. Increased temperatures result in lower winter demand for electricity, offset by higher summer demands. Increased populations in general increase electricity demand throughout the year. Higher summer peak load demands might be attributed to increases in the overall population, increases in air-conditioning, as well as the increase in the number and use of dual residences in the summer for recreation.

From a power generation standpoint, it is necessary to generate electricity to meet electricity demands. The cycle of annual electricity demand at the beginning and during the early life of the project produced peak demands during the winter months, December through March. Recent demand forecasts suggest that Great Lakes basin utilities will be facing a shift from a winter peaking system to a summer peaking system.

6.5.5

Optimal Conditions

1. Lake St. Lawrence - New York Power Authority & Ontario Power Generation

1. Minimize the frequency of flows above best efficiency.
   • Efficiency flow varies with head. In addition, modifications to turbine machinery result in changes to the efficiency flows. Average operating head at the Moses-Saunders power plant over the past 37 years is 24.8 metres. A long-term modification program will change the 24.8 metre efficiency flow from approximately 7840 m³/s to approximately 8400 m³/s by 2012. Currently, the efficiency flow at 24.8 metre head is 8200 m³/s.
2. Minimize the frequency of flow/level combinations that result in Long Sault levels above 73.9 metres.
   • Generally, elevations above 73.9 metres require Iroquois Dam to be operated to reduce the Lake St. Lawrence level.
   • An approximation of this would be to minimize the frequency of flows below 6000 m³/s.
3. With ice cover, minimize frequency of flows above 7400 m³/s.
   • Flows generally less than 7400 m³/s are preferred to reduce the risk of ice cover failure. Maintenance of a strong ice cover allows flow capacity to be maintained throughout the winter period.
   • The physical condition of the ice plays an important role in the capacity under ice cover conditions. Stronger ice has allowed flows higher than the nominal 7400 m³/s to be released while weak ice has limited flows to less than this amount in a few cases.
4. Minimize the frequency of flows above 6230 m³/s (220,00 ft³/s) during ice cover formation.
   • To permit ice formation, channel enlargements were designed to ensure the maximum velocity in any cross-section of the channel between the Lotus Island and Iroquois Point, and from above Point Three Points to below Ogden Island, does not exceed 0.69 m/s (2.25 feet/s) at an outflow of 6230 m³/s (220,000 ft³/s).
   • Although the start of the ice cover formation period has been recorded each year since 1960, the duration of the formation period has not been recorded. As a result, determining this period for each year is not possible. Each winter, ice first begins to form downstream of the International Section and then progresses upstream. This timing is highly variable depending on the weather. Ice in the International Section has begun to form anytime from early December to late January.
5. Minimize the magnitude of average week to week flow changes, except as needed for ice management.
   • Hydro plant equipment requires periodic servicing. Normally, the servicing is scheduled during the low flow periods in order to avoid spillage. Large week to week flow changes or fluctuations can disrupt a planned outage schedule and power production plan. In some cases, the flow changes may cause unnecessary spillage.
   • Large week to week flow changes can cause large fluctuations in the level of Lake St. Lawrence. The largest week to week changes in elevation have occurred during the winter and are due to ice restrictions and winter regulation flow changes.
6. Pass relatively higher flow in the high demand periods of the winter and summer.
   • Annual electricity demand curves, at the beginning and during the early life of the project, peaked during the winter months of December through March.
   • Changing demographics and changing climate in the Great Lakes basin over the later part of the century have resulted in a growth of the summer demand for electricity. It is anticipated that by 2005 Ontario will shift from a winter peaking to a summer peaking system on a weather normal basis.
7. Maximize the energy production
   • The St. Lawrence River is one of the most dependable flowing rivers in the world due to the size of the watershed. Any change in the regulation may not have a very large impact on hydropower from year to year. However, the timing of the flow distribution within the year has the greatest effect on impacts to the hydro plant operators. It is more beneficial to generate more power when power demand is greatest. Typically highest demand has been in the winter months. However, an increase in the summer peak demands over the last decade has moved the summer peak closer to winter peak demands.

2. Beauharnois-Cedars Complex

The Beauharnois-Cedars Complex is composed of two powerhouses. The complex is not located within the international section of the St. Lawrence River and therefore is not subject to the authority of the IJC. However, water that flows through the St. Lawrence control works for Lake Ontario run downstream through this complex. Thus, there is a downstream impact of the Beauharnois-Cedars Complex caused by Lake Ontario regulation.

The head is 24 metres at Beauharnois and 12 metres at Cedars. The best efficiency flow at Beauharnois, with all the units available (36 units), is 7300 m³/s and the production factor is 0.20 MW/ m³/s. The maximum flow capacity is 8200 m³/s. Between 7300 and 8000 m³/s, the average incremental flow efficiency is approximately 0.10 MW/m³/s (50% of the best efficiency point), which is similar to the best efficiency of the Cedars powerhouse (0.10 MW/m³/s). Between 8000 and 8200 m³/s at Beauharnois, the incremental flow efficiency is close to zero. The minimal flow at Cedars is 300 m³/s. The maximum flow with the 17 units available at Cedars is 1700 m³/s.

In summary, with 36 units available at Beauharnois and 17 at Cedars, best efficiency is obtained up to a maximum inflow of 7600 m³/s (7300+300). The efficiency falls to 50% for the incremental flow between 7600 and 9700 m³/s and the flow is spilled above 9700 m³/s.

Because of the large number of units and the limited capacity of Beauharnois, the maintenance program has an important impact on the capacity of the powerhouses. The number of units available is 32-33 at Beauharnois and 14 at Cedars and should be considered to be more representative of the normal conditions. In practice, the production factor is 0.2 MW/m³/s for inflow from Moses-Saunders up to 7000 m³/s and 0.1 MW/m³/s for incremental inflow between 7000 and 8400 m³/s and 0.0 MW/m³/s above 8400 m³/s.

As the local inflow to Lake St. Francis varies typically between 0 and 1500 m³/s during the year, with an average of 200 m³/s, these inflows have an important impact during the freshet.

These characteristics of the Beauharnois-Cedars Complex have two main impacts on the requirements to maximise the production:

• flows must be as stable as possible throughout the year (except as required during the formation of an ice cover). For example, it is much more efficient to pass 7000 m³/s all the time than 6000 m³/s and 8000 m³/s 50% of the time each.
• accurate flow forecasts for the longest period possible is very important in reducing the impact of the maintenance program.

3. Ice Management at Beauharnois-Cedars

The ice cover at Beauharnois begins about one week earlier than at Moses-Saunders. During the ice cover formation, the flow in the Beauharnois canal must be lowered to an average of 4500 m³/s for about two weeks (including a maximum of 4000 m³/s for 1 day) and the maximum safe flow at Cedars is 1800 m³/s (maximum flow which can be managed with gates under remote control). In practice, the maximum flow of 6230 m³/s used for ice formation at Moses-Saunders is valid also as an average for Beauharnois-Cedars. Under lower Lake Ontario supply conditions, the value of 6100 m³/s is more adequate. In any case, the flows are subject to daily adjustments. After the ice cover formation, the ice restriction limits the flow at about 7000 m³/s in the Beauharnois canal for the rest of the winter.

In conclusion, the following typical conditions must be taken into consideration:

1. Minimize the frequency of flows above 8400 m³/s.
2. Minimize the frequency of flows below 6000 m³/s.
3. Minimize the frequency of flows above 6100 m³/s during ice cover formation.
4. Pass relatively higher flow in the high demand periods of the winter and summer.
5. Minimize the magnitude of average week to week flow changes, except as needed for ice management.
6. Flexibility in the regulation plan to vary the timing of flow reductions for ice formation.
7. Flexibility in the regulation plan to vary the timing of flow increases to meet energy demands.
8. Flow must be foreseeable several weeks in advance.

6.5.6

Study Organization, Cost & Schedule

The studies and evaluations would be conducted by the power entities listed in Annex 1 and results evaluated by the overall Study Team. Study organization, cost and schedules are highly dependent on the number of evaluations required by the criteria review study. Each time a regulation plan is developed and resultant outflow and head determined, a coordinated assessment of the impact to hydropower would need to be undertaken. It is anticipated that a response time for an impact evaluation would be in the order of two months with an estimated cost of $20,000 U.S. and $60,000 Canadian per evaluation. For budget purposes, a total of ten evaluations, spread over years 4 and 5 of the Study was assumed.

6.6	Domestic, Industrial and Municipal Water Uses

6.6.1

Relationship to Water Level Fluctuations

In general, municipal water supplies are unaffected by fluctuating water levels in the Lake Ontario-St. Lawrence River system. The reason for this is that most, if not all, municipal water intakes are located such that the depth of water over them ranges from 20 to 40 feet. This affords them a measure of protection from damages resulting from both commercial and recreational boating activities. It also protects them from damage caused by icing conditions and floating materials. It has been found that the quality of water supplies taken from these depths is far superior to that taken from shallow water depths.

During the fall (low water period) of 1998, individual "shore well" water supplies along the shores of eastern Lake Ontario experienced problems which required expensive corrective action by the owners in order to provide adequate potable water. The problem was noted on both sides of the border as well as the Thousand Islands section of the St. Lawrence River. Similar experiences have occurred in the Lake St. Lawrence area during periods of high discharges from the system.

On the U.S. side of the system, the New York State Department of Health strictly regulates municipal water intakes. The Ontario Ministry of the Environment and Energy and the Ministère de l' Environnement du Quebec , Quebec, as well as local conservation authorities are responsible on the Canadian side. Current regulations require that new facilities be installed at depths which make them unaffected by fluctuating water levels in the system, even levels that could exceed those set by the Orders of Approval.

6.6.2

Past Studies

The report to the governments by the International Joint Commission titled "Great Lakes Diversion and Consumptive Uses" issued in January 1985 addressed the issue of "Domestic, Industrial and Municipal Water Uses". In addition, the "Levels Reference Study, Great Lakes-St. Lawrence River Basin" submitted by the Levels Reference Study Board to the IJC in March 1993 touched on the same subject to a degree. However there has never been a complete study of the potential problems that water level fluctuations might cause to domestic, industrial or municipal uses.

6.6.3

New Study Scope, Data Collection Needs and Evaluation Methods

To adequately assess the potential for problems caused by the fluctuation of the levels of Lake Ontario and the St. Lawrence River as far as Trois-Rivières, Quebec, a complete inventory of the municipal and industrial water intakes and treatment facilities (locations) must be undertaken. Private domestic water intakes present a more serious problem that will be discussed separately.

1. Municipal and Industrial Supplies

A typical inventory of a municipal or industrial supply must, of necessity, include the following steps:

1. Identification of the facility having water supply intakes in either Lake Ontario or the St. Lawrence River. This will require multiple meetings with regulatory agencies, review of any files and/or information available in New York, Ontario and Quebec.
2. Site visit to include acquiring pertinent data and available maps of the facility and intake. At this time, it is estimated that there are approximately 100 sites to be visited, and information from each to be gathered and cataloged.
3. Interview with the facility operator to determine any past or potential problems caused by fluctuating water levels.
4. Inclusion of acquired data into database.
5. Cataloging of all maps, plans and/or diagrams for future reference.

2. Private Domestic Supplies

As previously stated, identification and inventory of private domestic water supplies would be a cost prohibitive exercise due to their unregulated nature as well as the sheer number of private users. Rather than attempt to identify and catalog users, a more effective procedure would be to interview known parties with recorded problems from water level fluctuations. From the results of those interviews, guidance could be provided to them and others through pertinent agencies or municipal governments for possible corrective measures and/or proper methods of installation of private supplies to minimize effects from water level fluctuations.

After all data is collected and duly recorded into a database, evaluation of the affects of wide swings in the levels of the pertinent bodies of water can be analyzed. Suggested corrective measures can be made for those systems that could possibly be adversely affected. The database could be used by other agencies having cogent interests in the results of the study. Some of those agencies might be:

• The New York State Department of Health
• The New York State Department of Environmental Conservation
• The U.S. Army Corps of Engineers
• Local Municipal jurisdictions of New York
• The Ministries of the Environment of Ontario and Quebec
• Environment Canada
• Fisheries and Oceans Canada
• Local Municipal Jurisdictions of Ontario and Quebec

6.5.4

Implications of Climate, Demographics and Other Changes

The importance of domestic, and sanitary water uses is recognized in the Boundary Waters Treaty which accords them a certain preference. Climate change could have a significant impact on the intakes that facilitate this use. Scenarios, which predict that lower water levels will occur, will affect the ability of intakes to draw water. However, each site will be affected differently and the inventory which will take place will determine the extent of the impact.

Demographics may increase water use which can have two affects in terms of water intakes: lower levels can reduce the ability of the intake to draw water and increased demand for water may stress the capacity of existing intakes to supply water. The inventory will include an itemization of intake characteristics that will allow the assessment of demographic impacts to be made.

6.6.5

Optimal Conditions

Since each intake and municipality is different, optimal conditions will be assessed on a case-by-case basis. Once each site is assessed, generalities will be identified and an optimal condition for overall use will be defined.

6.6.6

Study Organization, Costs and Schedule

Because of the great amount of time required to accomplish the large number of site visits, the study organization for those tasks perhaps should be private consulting engineering companies in New York State, as well as in Ontario and Quebec provinces, and other agencies as listed in Annex 1, the results of which will be evaluated by a binational Study Team.

Table 6a. Time and Cost Estimates - Water Uses Studies (U.S. $K)

Table 6b. Time and Cost Estimates - Water Uses Studies (Cdn. $K)