MODELING HYDROLOGIC IMPACT OF WITHDRAWING THE GREAT LAKES WATER FOR AGRICULTURAL IRRIGATION1

ABSTRACT: Growing interest in agricultural irrigation in the Great Lakes basin presents an increasing competition to other uses of Great Lakes water. This paper, through a case study of the Mud Creek Irrigation District in the Saginaw Bay basin, Michigan, evaluates the potential hydrologic effects of withdrawing water for agricultural irrigation to the Great Lakes. Crop growth simulation models for corn, soybeans, dry beans, and the FAO Penman method were used to estimate the difference in evapotranspiration rates between irrigated and nonirrigated identical crops, based on climate, soil, and management data. The simulated results indicate that an additional 70–120 mm of water would be evapotranspirated during the growing season from irrigated crop fields as compared to nonirrigated identical plantings. Dependent upon the magnitude of irrigation expansion, an equivalent of about 1 to 5 mm of water from Lakes Huron-Michigan could be lost to the atmosphere. If agricultural irrigation further expands in the entire Great Lakes basin, the aggregated potential of water loss to the atmosphere through ET from all five Great Lakes would be even greater.     

PRECIPITATION AUGMENTATION-PROBLEMS AND PROGRESS1

ABSTRACT: Advances in the science of weather modification have provided an opportunity for significant progress in the area of precipitation management. Coordination of efforts and intensification of both laboratory and field research could lead to major advances within the decade. In view of the important decision-making role played by society, however, it is necessary that our scientific efforts be coordinated with a public relations program designed to inform and educate the public on the role and potential of artificial precipitation augmentation. In addition, careful consideration must be given to those social and legal issues related to weather modification. Environmental impact, land use, economic potential and damage liability are aU factors of importance in any comprehensive analysis. Rational solutions to questions in each of these areas is dependent upon the establishment of a sound scientific basis for operational weather modification, which should be the first priority.     

Relative cancer risks of chemical contaminants in the great lakes

Anyone who drinks water or eats fish from the Great Lakes consumes potentially carcinogenic chemicals. In choosing how to respond to such pollution, it is important to put the risks these contaminants pose in perspective. Based on recent measurements of carcinogens in Great Lakes fish and water, calculations of lifetime risks of cancer indicate that consumers of sport fish face cancer risks from Great Lakes contaminants that are several orders of magnitude higher than the risks posed by drinking Great Lakes water. But drinking urban groundwater and breathing urban air may be as hazardous as frequent consumption of sport fish from the Great Lakes. Making such comparisons is difficult because of variation in types and quality of information available and in the methods for estimating risk. Much uncertainty pervades the risk assessment process in such areas as estimating carcinogenic potency and human exposure to contaminants. If risk assessment is to be made more useful, it is important to quantify this uncertainty.     

EFFECTS OF DIVERSIONS ON THE NORTH AMERICAN GREAT LAKES1

ABSTRACT: Water level fluctuations of the Great Lakes often have created regional controversies among the states and Canadian provinces that share this vast resource. Even though the 100-year range of their water levels is only four to five feet, episodes of high and low Great Lakes water levels have been a recurring problem throughout the twentieth century. The possibility of increased diversion and consumptive use has exacerbated the existing conflicts over how to manage this water resource. A research project evaluated the effects of interbasin diversion on the Great Lakes system and on the industries that depend on the maintenance of historical water levels, namely hydropower and commercial navigation. The simulation approach employed in this research and some of the important findings are presented. The approach is similar to that used in recent government studies of Great Lakes water level regulation. Several significant modifications were made specifically addressing the diversion issue. Aggregate annual impacts to hydropower and shipping resulting from a diversion of 10,000 cubic feet per second were found to vary from 60 to 100 million dollars. Increases in impacts as a function of diversion rate are nonlinear for the navigation industry.     

EFFECT OF INFLUENT PHOSPHORUS REDUCTIONS ON GREAT LAKES SEWAGE TREATMENT COSTS1

ABSTRACT: Controlling phosphorus sources, such as laundry detergents, for eutrophication control has been the aim of water resources management in many areas. However, the advisability of limiting phosphorus in raw wastewater continues to be debated. One aspect that has received little attention is the cost savings at sewage treatment plants practing phosphorus removal. It is estimated, based on available data and observations where detergent phosphorus has been reduced, that cost savings could range from about $0.20 to $1.70 per capita per year for an influent reduction of about 1.5 mg/L of phosphorus. These savings result mostly from a decrease in the amount of chemicals needed to remove phosphorus at the plant as well as a decrease in sludge production. For the U.S. Great Lakes basin, total annual savings amounting to several million dollars are projected given a basin-wide ban. Although estimates of cost savings are presented for the Great Lakes basin, the results are applicable to other areas where phosphorus controls are being considered.     

LAKE ONTARIO REGULATION UNDER TRANSPOSED CLIMATES1

ABSTRACT: The implications of Lake Ontario regulation under transposed climates with changed means and variability are presented for seasonal and annual time scales. The current regulation plan is evaluated with climates other than the climate for which it was developed and tested. This provides insight into potential conflicts and management issues, development of regulation criteria for extreme conditions, and potential modification of the regulation plan. Transposed climates from the southeastern and south central continental United States are applied to thermodynamic models of the Great Lakes and hydrologic models of their watersheds; these climates provide four alternative scenarios of water supplies to Lake Ontario. The scenarios are analyzed with reference to the present Great Lakes climate. The responses of the Lake Ontario regulation plan to the transposed climate scenarios illustrate several key issues: (1) historical water supplies should no longer be the sole basis for testing and developing lake regulation plans; (2) during extreme supply conditions, none of the regulation criteria can be met simultaneously, priority of interests may change, and new interests may need to be considered, potentially requiring substantial revision to the Boundary Waters Treaty of 1909; (3) revised regulation criteria should be based on ecosystem health and socio-economic benefits for a wider spectrum of interests and not on frequencies and ranges of levels and flows of the historical climate; and (4) operational management of the lake should be improved under the present climate, and under any future climate with more variability, through the use of improved water supply forecasts and monitoring of current hydrologic conditions.     

HYDROLOGIC IMPACT OF WEATHER MODIFICATION1

ABSTRACT: Weather modification is being proposed as a routine method of augmenting agricultural water supplies in the Southern Great Plains. This paper discusses some of the potential hydrologic impacts of weather modification. Previous work in assessing hydrologic impact is covered; the conclusion is drawn that the work is insufficient. An approach based on hydrologic models is suggested that can consider uncertainties about the effect of weather modification on rainfall and some uncertainties about the effect of model error on impact conclusions.     

EFFECTS OF THE URBAN ENVIRONMENT ON HEAVY RAINFALL DISTRIBUTION1

ABSTRACT: A network of 225 recording raingages was operated over an area of 5200 km² in the St. Louis region during 1971-1975, in conjunction with an extensive investigation of urban effects on precipitation. Study of urban-induced effects on the frequency of heavy rainstorms has revealed a pronounced increase in the occurrence of storms producing 25 mm (1 inch) or more of rain. The increase is greatest in an area that is frequently in the path of storms passing across two urban-industrial regions. Analyses of raincells (rain intensity centers) within heavy convective storms shows a pronounced increase in water yield from cells exposed to potential urban effects, compared with those exposed only to the surrounding rural environment. Naturally-occurring heavy cells tend to undergo the greatest enhancement from urban exposure. Other analyses indicate an above-average frequency of excessive rain rates for periods of five minutes to two hours downwind of the urban-industrial complex. It is concluded that urban-induced intensification of short-duration rainstorms is sufficient to merit inclusion in the design and operation of urban-area hydrologic systems that control the flow of surplus storm water.     

Flooding and erosion hazards on the ontario great lakes shoreline: a human ecological approach to planning and management

Understanding flood and erosion hazards in the context of developing coastal management plans requires an appreciation for variations in climate, geology, vegetation, land uses, human activities and institutional arrangements. On the Great Lakes, fluctuating water levels are characterized by temporal variations in their magnitude and frequency and their impact on flooding and erosion also differ from site to site. The traditional planning and management mechanisms in Ontario, through the use of emergency responses and land use setbacks, have been insufficient in resolving the rising costs of damage to property due to flooding and erosion along the Great Lakes shoreline. There is a need to develop an alternative management model with a focus on understanding hazards in the context of their natural and human components. A case study of the preparation of a resource survey for the Saugeen Valley Conservation Authority illustrates the development of a human ecological approach and its applicability in developing shoreline management plans for the Great Lakes.     

MODELING THE IMPACTS OF WATER LEVEL CHANGES ON A GREAT LAKES COMMUNITY1

ABSTRACT: Recent research that couples climate change scenarios based on general circulation models (GCM) with Great Lakes hydrologic models has indicated that average water levels are projected to decline in the future. This paper outlines a methodology to assess the potential impact of declining water levels on Great Lakes waterfront communities, using the Lake Huron shoreline at Goderich, Ontario, as an example. The methodology utilizes a geographic information system (GIS) to combine topographic and bathymetric datasets. A digital elevation surface is used to model projected shoreline change for 2050 using water level scenarios. An arbitrary scenario, based on a 1 m decline from February 2001 lake levels, is also modeled. By creating a series of shoreline scenarios, a range of impact and cost scenarios are generated for the Goderich Harbor and adjacent marinas. Additional harbor and marina dredging could cost as much as CDN $7.6 million. Lake freighters may experience a 30 percent loss in vessel capacity. The methodology is used to provide initial estimates of the potential impacts of climate change that can be readily updated as more robust climate change scenarios become available and is adaptable for use in other Great Lakes coastal communities.     

Water Quality and Plankton in the United States Nearshore Waters of Lake Huron

Our goal in the development of a nearshore monitoring method has been to evaluate and refine an in situ mapping approach to assess the nearshore waters across the Great Lakes. The report here for Lake Huron is part of a broader effort being conducted across all five Great Lakes. We conducted an intensive survey for the United States nearshore of Lake Huron along a continuous shoreline transect (523?km) from Port Huron, Michigan, to Detour Passage. A depth contour of 20?m was towed with a conductivity-temperature depth profiler, fluorometer, transmissometer, and laser optical plankton counter. Multiple cross-contour tows (10-30?m) on the cruise dates were used to characterize the variability across a broader range of the nearshore. The cross-contour tows were comparable with the alongshore contour indicating that the 20-m contour does a good job of representing the nearshore region (10-30?m). Strong correlations were observed between water quality and spatially associated watershed land use. A repeat tow separated by several weeks investigated temporal variability in spatial patterns within a summer season. Strong correlations were observed across each variable for the temporal repeat across broad- and fine-scale spatial dimensions. The survey results for Lake Huron nearshore are briefly compared with a similar nearshore survey in Lake Superior. The biomass concentrations of lower food web components of Lake Huron were notably approximately 54-59?% of those in Lake Superior. The towed instrumentation survey supported the recent view of a change in Lake Huron to an ultra-oligotrophic state, which has been uncharacteristic in recent history.     

WEATHER MODIFICATION: AN ECONOMIC ALTERNATIVE FOR AUGMENTING WATER SUPPLIES1

ABSTRACT. Experimental results of cloud seeding in Southwestern Colorado suggest that runoff can be increased by 25 percent over a 3,300 mile area. There is a need to estimate the economic consequences in the Colorado River Basin. The evidence presented suggests that weather modification is an economically feasible means to provide additional water for the basin. Compared with other proposed means of augmenting water supplies, weather modifications appear to be one of the least cost alternatives. A very low proportion of weather modification costs are fixed; thus the program is easily reversible. Also, a relatively small increase in daily precipitation covers the direct costs of operation. Benefits of water produced by weather modification included power production and irrigation of forage crops. In the long run, if additional water is used for higher valued fruit and vegetable production, or for domestic and industrial purposes, its value would rise sharply. Preliminary investigation of extra-market costs and benefits suggests that while they have little effect on the benefit-cost ratio, they may be very important to individuals and groups affected. The distribution of costs and benefits is important as the benefits accrue to downstream users and some of the costs are incurred by Coloradoans. There is a need for further research on the long-run economic effects of weather modification programs, particularly with respect to extra-market factors.     

Assessing Risk in Operational Decisions Using Great Lakes Probabilistic Water Level Forecasts

/ A method adapted from the National Weather Service's Extended Streamflow Prediction technique is applied retrospectively to three Great Lakes case studies to show how risk assessment using probabilistic monthly water level forecasts could have contributed to the decision-mak-ing process. The first case study examines the 1985 International Joint Commission (IJC) decision to store water in Lake Superior to reduce high levels on the downstream lakes. Probabilistic forecasts are generated for Lake Superior and Lakes Michigan-Huron and used with riparian inundation value functions to assess the relative impacts of the IJC's decision on riparian interests for both lakes. The second case study evaluates the risk of flooding at Milwaukee, Wisconsin, and the need to implement flood-control projects if Lake Michigan levels were to continue to rise above the October 1986 record. The third case study quantifies the risks of impaired municipal water works operation during the 1964-1965 period of extreme low water levels on Lakes Huron, St. Clair, Erie, and Ontario. Further refinements and other potential applications of the probabilistic forecast technique are discussed.KEY WORDS: Great Lakes; Water levels; Forecasting; Risk; Decision making     

Great Lakes management: Ecological factors

Although attempts to improve the quality of the Great Lakes generally focus on chemical pollution, other factors are important and should be considered Ecological factors, such as invasion of the lakes by foreign species, habitat changes, overfishing, and random variations in organism populations, are especially influential. Lack of appreciation of the significance of ecological factors stems partly from the inappropriate application of the concept of eutrophication to the Great Lakes. Emphasis on ecological factors is not intended to diminish the seriousness of pollution, but rather to point out that more cost-effective management, as well as more realistic expectations of management efforts by the public, should result from an ecosystem management approach in which ecological factors are carefully considered.     

MODELING OF THE GREAT LAKES WATER SYSTEM1

There have been two predominate approaches to the modeling of the Great Lakes water system: physical models and mathematical models. The physical models have been of individual lakes whereas the mathematical models have varied from models of individual processes such as evaporation occurring in one portion of one lake to models which include all water quantity components for all five Great Lakes. The assumptions and limitations of the two approaches are presented along with the kinds of results to be expected from each type of modeling. Examples of previous modeling efforts are given to illustrate these assumptions, limitations, and results. Other areas requiring further research are outlined.     

Implementing Ecosystem-basedManagement: Lessons from the Great Lakes

Under the US-Canada Great Lakes Water Quality Agreement, a Remedial Action Plan (RAP) Program was formalized to identify and implement actions needed to restore beneficial uses in the most polluted areas of the Great Lakes (i.e. Areas of Concern). It was further required that individual RAPs embody a systematic and comprehensive ecosystem approach (i.e. an approach which accounts for interrelationships among land, air, water and all living things, including humans, and involves user groups in comprehensive management). Careful review and analysis of the RAP Program offers an opportunity to gain a better understanding of ecosystem-based management for other watersheds, and to identify important principles and elements which contribute to effective implementation. Principles which are considered essential for effective implementation of ecosystem-based management include: (1) broad-based stakeholder involvement; (2) commitment of top leaders; (3) agreement on information needs and interpretation; (4) action planning within a strategic framework; (5) human resource development; (6) results and indicators to measure progress; (7) systematic review and feedback; and (8) stakeholder satisfaction. The Great Lakes RAP experience with ecosystem-based management also demonstrates the need for a transition from a traditional,command-and-control,regulatory approach of governmentalagencies toward a more co-operative,value-added,support-basedrole. Review of RAPs in all 42 Areas of Concern provides compelling evidence that successful application of ecosystem-based management is dependent on broad-based stakeholder involvement in decision making, along with strong partnerships which encourage collaboration, co-operation and adaptability in management actions.     

A Decision‐Analytic Approach to Managing Climate Risks: Application to the Upper Great Lakes1

Brown, Casey, William Werick, Wendy Leger, and David Fay, 2011. A Decision‐Analytic Approach to Managing Climate Risks: Application to the Upper Great Lakes. Journal of the American Water Resources Association (JAWRA) 47(3):524‐534. DOI: 10.1111/j.1752‐1688.2011.00552.x Abstract: In this paper, we present a risk analysis and management process designed for use in water resources planning and management under climate change. The process incorporates climate information through a method called decision‐scaling, whereby information related to climate projections is tailored for use in a decision‐analytic framework. The climate risk management process begins with the identification of vulnerabilities by asking stakeholders and resource experts what water conditions they could cope with and which would require substantial policy or investment shifts. The identified vulnerabilities and thresholds are formalized with a water resources systems model that relates changes in the physical climate conditions to the performance metrics corresponding to vulnerabilities. The irreducible uncertainty of climate change projections is addressed through a dynamic management plan embedded within an adaptive management process. Implementation of the process is described as applied in the ongoing International Upper Great Lakes Study.     

CLIMATIC VARIATION AND SURFACE WATER RESOURCES IN THE GREAT BASIN REGION1

ABSTRACT: There is mounting evidence that increasing amounts of atmospheric carbon dioxide may lead to significant changes in global climate during the next century. The possible effects of such climatic changes on surface runoff in the Great Basin Region of the western United States has been investigated by applying water balance models to four watersheds in Nevada and Utah. The most probable change, a 2°C increase in average annual temperature coupled with a 10 percent decrease in precipitation, would reduce runoff from 17 to 28 percent of the present mean, with drier basins showing the greatest change. Decreasing precipitation by 25 percent causes runoff reductions of 33 to 51 percent. Equivalent changes to a cooler and wetter climate show corresponding increases in runoff of approximately the same magnitude, but such a shift is not considered likely. Based on projected water requirements for the year 2000, a change to a warmer and drier climate would cause severe water shortages in many parts of the Great Basin.     

POTENTIAL CLIMATE CHANGE IMPACTS ON WATER RESOURCES IN THE GREAT PLAINS1

ABSTRACT: This paper reports on the current assessment of climate impacts on water resources, including aquatic ecosystems, agricultural demands, and water management, in the U.S. Great Plains. Climate change in the region may have profound effects on agricultural users, aquatic ecosystems, and urban and industrial users alike. In the central Great Plains Region, the potential impacts of climate changes include changes in winter snowfall and snow-melt, growing season rainfall amounts and intensities, minimum winter temperature, and summer time average temperature. Specifically, results from general circulation models indicate that both annual average temperatures and total annual precipitation will increase over the region. However, the seasonal patterns are not uniform. The combined effect of these changes in weather patterns and average seasonal climate will affect numerous sectors critical to the economic, social and ecological welfare of this region. Research is needed to better address the current competition among the water needs of agriculture, urban and industrial uses, and natural ecosystems, and then to look at potential changes. These diverse demands on water needs in this region compound the difficulty in managing water use and projecting the impact of climate changes among the various critical sectors in this region.     

Managing mercury in the great lakes: an analytical review of abatement policies

Mercury, a toxic metal known to have several deleterious affects on human health, has been one of the principal contaminants of concern in the Great Lakes basin. There are numerous anthropogenic sources of mercury to the Great Lakes area. Combustion of coal, smelting of non ferrous metals, and incineration of municipal and medical waste are major sources of mercury emissions in the region. In addition to North American anthropogenic emissions, global atmospheric emissions also significantly contribute to the deposition of mercury in the Great Lakes basin. Both the USA and Canada have agreed to reduce human exposure to mercury in the Great Lakes basin and have significantly curtailed mercury load to this region through individual and joint efforts. However, many important mercury sources, such as coal-fired power plants, still exist in the vicinity of the Great Lakes. More serious actions to drastically reduce mercury sources by employing alternative energy sources, restricting mercury trade and banning various mercury containing consumer products, such as dental amalgam are as essential as cleaning up the historical deposits of mercury in the basin. A strong political will and mass momentum are crucial for efficient mercury management. International cooperation is equally important. In the present paper, we have analyzed existing policies in respective jurisdictions to reduce mercury concentration in the Great Lakes environment. A brief review of the sources, occurrence in the Great Lakes, and the health effects of mercury is also included.