Priority – enhancing understanding and adaptation

Annex 9: groundwater quality

The purpose of this annex is to gain a better understanding of how groundwater influences Great Lakes water quality and ecosystem health, and to identify priority areas for future action.

Groundwater may represent as much as over 40 percent of the water entering the Great Lakes, either directly (via groundwater discharge along the coasts) or indirectly (via discharge into rivers and streams that then discharge into the lakes). As a result, the continued flow of good quality groundwater plays an important role in Great Lakes water quality and ecosystem health. Groundwater-transported contaminants and excessive nutrients can impair the quality of the waters of the Great Lakes, particularly the nearshore region, with potential effects on aquatic species, recreational waters and water supplies.

Because groundwater is an important source of water and a potential source of contaminants and excessive nutrients and a pathway for transfer to the Great Lakes, groundwater quality is linked to the successful delivery of key commitments in other annexes, including areas of concern, lakewide management, harmful pollutants, nutrients, and habitat and species.

Some areas near the Great Lakes are known to have contaminated groundwater. In some cases, initiatives are underway to direct management and/or implement remediation actions in these locations. They include numerous contaminated site risk assessment and remediation projects undertaken by private industry across the province, provincial contaminated site remediation efforts such as the Deloro Mine Site, and some of the work done through the Federal Contaminated Sites Action Plan, and the federal remediation of the Port Hope Area. These actions will protect or improve the water quality of the Great Lakes.

This annex includes commitments to update a binational state of groundwater science report, identify priorities for future research, and identify priority areas and sites for monitoring, management or remediation actions to address groundwater impacts and stressors.

Result 1

A binational state of groundwater science report, based on collecting and compiling groundwater science findings, is updated and made available.

Canada will, with Ontario’s support:

1. By 2022, in cooperation with the United States, update the 2016 binational state of groundwater science report synthesizing relevant and available groundwater science; and
2. Assemble technical and scientific expertise to:
   1. Update the state of groundwater science as it pertains to implications for Great Lakes water quality and ecosystem health; and
   2. Identify priorities for groundwater science.

Result 2

Improved understanding of groundwater-surface water interactions and their influence on the Great Lakes water quality and ecosystem health to inform management actions and decisions.

Ontario will, with Canada’s support:

1. Support the development of surface water-groundwater conceptual and numerical models at Great Lakes, basin, watershed and aquifer scales; and
2. Undertake and promote monitoring and research to improve understanding of groundwater influences on Great Lakes water quality and ecosystem health.

Ontario will:

3. Maintain its provincial groundwater, surface water and integrated climate change monitoring and use these data to update Ontario’s contribution to the binational Great Lakes groundwater ecosystem indicator and explore groundwater-surface water interactions.

Result 3

Improved understanding of groundwater impacts and stressors on Great Lakes water quality and ecosystem health and identification of priority areas for the development of monitoring, management or remediation actions.

Canada and Ontario will:

1. Facilitate the coordination, sharing and exchange of information and research to improve understanding of groundwater impacts on Great Lakes water quality and ecosystem health; and
2. Identify priority sites or areas where point sources may impact the water quality and ecosystem health of the Great Lakes, including nearshore areas.

Annex 10: climate change impacts and resilience

The purpose of this annex is to continue to build understanding of climate change impacts, advance the integration of this knowledge into Great Lakes adaptation strategies and management actions, and help communities build climate resilience.

Climate change impacts are being observed in the Great Lakes. Some of the most evident impacts include warmer water temperatures, changing precipitation patterns, extreme variability in lake levels, decreased ice coverage, and increased lake evaporation and extreme weather events.

National efforts to help Canadians adapt to climate change complement the commitments under this annex. Natural Resources Canada’s Adaptation to Climate Change program facilitates the development and exchange of information, knowledge and tools required to plan and implement practical measures that increase climate resilience. Regional adaptation planning, decision-making and action are supported through this program with the aim of helping communities and industry prepare for and adapt to local climate change impacts including increasing droughts, floods, coastal erosion and snow and ice storms. Canada also works with many partners to improve our ability to predict and manage flood risk.

Ontario’s climate change programs and efforts will support the commitments of this annex. This includes improving our understanding of climate change impacts by investing in regional scale climate change projections using the latest global climate model data. Ontario is also undertaking a provincial climate change impact assessment to further support communities, businesses and municipalities, including those in the Great Lakes watershed, in identifying vulnerabilities and impacts across the Province. Further, Ontario is developing an on-line tool to support the sharing of information by making practical climate impact information available for the public and private sectors. Ontario will continue to work with partners across the province to support local leadership and to build climate change adaptation knowledge.

Climate change affects physical, chemical and biological processes and aquatic ecosystems in the Great Lakes. It also impacts people, public health, communities, and infrastructure in the Great Lakes basin. For example, warmer water temperatures can result in increased algae blooms, changes to the rates of biological productivity, and effects on water quality; extremes in water levels pose significant risks to the Great Lakes including implications for water quality and ecosystem functions (see also the nutrients, harmful pollutants, lakewide management and groundwater annexes); changes in precipitation patterns may affect shoreline processes and increase the concentration of nutrients, which may in turn increase harmful and nuisance algae blooms; and native fish and wildlife habitats, populations and diversity may be affected by changes to ecosystem functions and by new or expanded ranges of invasive species (see also the aquatic invasive species and habitat and species annexes).

This annex contains commitments that will: improve our understanding of climate change impacts on Great Lakes water quality and ecosystem health; assess existing and future climate change vulnerabilities and risks; advance the integration of climate change considerations into Great Lakes management strategies; share climate change information with the Great Lakes community including decision-makers and resource managers; and help communities build climate change resilience and adapt to climate change.

Result 1

Enhance knowledge and understanding of existing and future climate change impacts in the Great Lakes.

Canada and Ontario will:

1. Maintain the monitoring of Great Lakes water levels and streamflow, via the cost-shared Ontario Hydrometric Network and binational work with United States federal and state agencies; and
2. Collaborate with others to apply national level climate research and modelling to regional scale projections for climate change elements such as air and water temperature, wind speeds, ice, humidity, streamflow, precipitation frequency, duration and intensity, and seasonal shifts, where feasible.

Canada will:

3. Maintain the monitoring of climate and weather variables, such as wind, temperature, precipitation, evaporation, wave height, water temperature, ice cover and Great Lakes water levels;
4. Improve the understanding of observed climate trends and variations and their effects on physical, chemical and biological processes affecting the Great Lakes; and
5. Provide support for the coordination of Synthetic Aperture Radar monitoring of the Great Lakes through the RADARSAT Constellation Mission.

Ontario will:

6. Work in collaboration with the academic community and others to update regional scale climate projections using latest global climate model data;
7. Share available down-scaled regional climate change data projections for the Great Lakes basin in Ontario;
8. Maintain Provincial networks for monitoring stream water quality and groundwater quantity and quality in the Great Lakes basin;
9. Operate and enhance existing integrated monitoring stations to support an understanding of how climate changes are influencing groundwater and stream water that potentially feed nutrients and contaminants into the Great Lakes; and
10. For Lake Ontario, extend seasonal coverage of water quality monitoring to capture extreme events and events that occur in the winter.

Result 2

Assess existing and future climate change risks and vulnerabilities of the Great Lakes.

Canada and Ontario will:

1. Building on national and provincial-level climate change impact assessments, explore the development of a Canada-Ontario Great Lakes climate change impact assessment;
2. Consider climate change impacts and changing climatic conditions in the development of management strategies and action plans under the agreement;
3. Provide support for the development and implementation of regional Great Lakes adaptive management initiatives with a focus on impacts to Great Lakes water quality and ecosystem health, including initiatives related to lake level uncertainties, vulnerabilities and risks; and
4. Assess vulnerabilities of aquatic species and ecosystems to projected changes in climate including trends and variation in temperature and ice cover.

Canada will:

5. Improve regional scale models and analytical tools (e.g., Intensity Duration and Frequency or IDF curves, water level and wind/wave analyses) in order to increase understanding of the risks, vulnerabilities and opportunities associated with climate change impacts to the Great Lakes; and
6. Support the Province, which is the lead jurisdiction for flooding and flood mitigation, as Ontario directs municipalities using established legislation and technical guidance towards continued advancement in the identification of areas subject to natural hazards, and supports municipal use of floodplain maps to inform statutory obligations under the Planning Act.

Result 3

Share information on climate change impacts, risks and vulnerabilities with the Great Lakes community, and advance the integration of climate change considerations into Great Lakes management strategies.

Canada and Ontario will:

1. Share climate and climate change impact-related data and information, including regional scale climate model outputs and research results, having implications for climate change impacts on Great Lakes water quality and ecosystem health with Great Lakes agencies, organizations and communities;
2. Communicate ongoing developments in science, strategies and actions to address climate change impacts within the Great Lakes;
3. Share data and expertise on water levels and water budgets of the Great Lakes, where feasible, as they relate to Great Lakes water quality and ecosystem health in order to promote the understanding of the impacts of climate change and advance action on climate change adaptation; and
4. Share information and results from the Provincial Climate Change Impact Assessment and the Canada in a Changing Climate series of reports.

Result 4

Communities are better prepared to adapt to climate change and build resilience.

Canada and Ontario will:

1. Work with others to increase the ability to implement adaptation actions and promote the use of adaptive management tools in the Great Lakes basin;
2. Explore opportunities to help Great Lakes communities consider climate change impacts to Great Lakes water quality and ecosystem health including, but not limited to, shoreline erosion, drought, and flooding, as part of community adaptation planning and initiatives to build community resilience; and
3. Work through the Adaptation Policy Committee of the Canadian Council of Ministers of the Environment, to continue to advance work on adaptation, including work related to natural infrastructure, assessing risks associated with climate change, and measuring progress.

Ontario will:

4. Undertake a compilation of local (municipal and community) climate change planning and initiatives completed or underway in the Great Lakes watershed.