Canada-Ontario Lake Erie action plan

Canada and Ontario have released the final Lake Erie Action Plan. The plan has more than 120 actions to help reduce how much phosphorus enters Lake Erie.  These actions will address harmful algal blooms and improve the health of the lake.

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Reduction targets for Lake Erie's eastern basin

Addressing excessive algal growth and shoreline fouling in Lake Erie’s eastern basin remains a priority, but additional research and modelling efforts are needed to support setting a reduction target. Until such research is available, Canada and Ontario will take precautionary actions to reduce phosphorus loads to the Grand River watershed and the eastern basin. This will help maintain levels of algal biomass below a level that would constitute a nuisance condition in the nearshore waters of the eastern basin.

In the spirit of adaptive management, the viability of setting evidence-based numeric targets for the eastern basin will be re-evaluated in 2020. In the interim, there will be support for targeted research efforts intended to improve the scientific understanding of how to effectively manage the Cladophora problem in the eastern basin and elsewhere in the Great Lakes.

How the plan aligns with key Ontario initiatives

This action plan will also help the Government of Ontario achieve its other nutrient commitments, including those outlined in the Great Lakes Protection Act, 2015 (GLPA).

The GLPA provides tools that can help address algal blooms in Lake Erie and enables partners to come together to achieve shared goals in a particular watershed or geographic area in the Great Lakes–St. Lawrence River basin. Under the GLPA, Ontario’s Minister of the Environment and Climate Change must set at least one target by November 2017 to help reduce algal blooms in all or part of the basin. To satisfy that obligation, in October 2016 the Minister adopted a target of 40 per cent phosphorus load reduction by 2025 (from 2008 levels), using an adaptive management approach, for the Ontario portion of the western and central basins of Lake Erie, as well as an aspirational interim goal of a 20 per cent reduction by 2020.

The GLPA also states that the Minister must prepare a plan setting out the actions to be taken to achieve those targets. This action plan for Lake Erie will serve as the Minister’s plan for meeting the GLPA targets to help reduce algal blooms in the lake.

In keeping with the need for early action, Ontario also signed the Western Basin of Lake Erie Collaborative Agreement with the U.S. states of Michigan and Ohio on June 13, 2015. The signatories collectively committed to work to achieve, through an adaptive management process, a recommended 40 per cent total load reduction in the amount of total and dissolved reactive phosphorus entering Lake Erie’s western basin by 2025, with an aspirational interim goal of a 20 per cent reduction by 2020 (from 2008 base year).

Working with the U.S. states bordering Lake Erie through the Great Lakes Commission, Ontario collaborated on the development of a joint action plan for Lake Erie, which aligns with other binational and domestic nutrient efforts currently underway.

Source: Environment and Climate Change Canada.

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How phosphorus is measured

Concentration is the mass of a substance present in a given volume of water expressed in units such as milligrams per litre. Measuring concentration is particularly useful when a substance has biological consequences, such as toxicity or eutrophication.

Load is the total mass of a substance delivered to a water body over a given time period. Loading rate is expressed in units of mass per unit time (e.g., kilograms/year) and is calculated as the product of concentration and flow rate (water volume per unit time). Load is a useful measure when there is potential for accumulation of a substance over time or when there is limited assimilative capacity in the receiving water. Load is also an important way of measuring the total pollutant contribution from a given source.

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Source: Michigan Sea Grant.

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Source: Agriculture and Agri-Food Canada.

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Source: Agriculture and Agri-Food Canada.

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Addressing non-point sources of phosphorus

With point sources well controlled, most of the phosphorus entering the lake now comes from non-point sources such as agricultural, rural and urban stormwater runoff. Controlling those sources can be challenging because solutions require changes on thousands of individual sites instead of a small number of known point sources, and must be tailored to particular land management and biophysical site characteristics.

A new approach to voluntary stewardship; targeted, supported and risk-based

Recognizing the significant contribution of agricultural activities to Lake Erie non-point source phosphorus loading, Ontario and Canada explored a new approach for fostering awareness and accelerating implementation of environmentally sustainable farm practices to reduce phosphorus loading to Lake Erie.

Through the Great Lakes Agriculture Stewardship Initiative (GLASI) — geographically targeted to the Lake Erie basin and the southeast shores of Lake Huron — professional support was provided to farmers to help them identify environmental risks specific to their farms as well as appropriate BMPs to reduce these risks. Farmers could then seek government cost-share funding to implement risk-reduction practices, including equipment modification, soil erosion control structures, cover crops, residue management, buffer strips and field windbreaks/wind strips.

Examples of natural heritage features

Natural heritage features can include structures such as natural channel formations, wetlands and the riparian zone, and the area of land adjacent to tributaries and the lake, where vegetation may be influenced by flooding or elevated water tables.

These features provide a range of ecosystem services, including:

  • water filtration
  • flood mitigation
  • erosion reduction
  • fish and wildlife habitat
  • nutrient cycling
  • pollinator habitat
  • ground water recharge
  • climate change mitigation
  • recreational, social, cultural and spiritual opportunities

By providing these important ecosystem services, healthy biodiverse ecosystems reduce Ontarians’ dependence on stormwater and wastewater infrastructure.

Ontario's wetlands -  past and present

Estimates suggest 68 per cent of wetlands that were present in Ontario before European settlement were drained to accommodate agricultural, industrial and residential land uses by the early 1980s, and an additional four per cent has been lost since that time. Localized loss within the Lake Erie basin has been higher, especially in the western portions of the basin.

Fortunately, the rate of wetland loss in southern Ontario has dropped over the last decade. Recent assessments show a total of 64,487 wetlands in the Lake Erie basin, covering 187,158 hectares.

Efforts to improve the health and functions of ecosystems in southern Ontario are ongoing; however, more work is needed to increase the extent of natural cover — including wetlands — in areas where losses have been greatest. Improvements in these areas will support ongoing phosphorus reduction efforts in the Lake Erie basin.

Source: Environment and Climate Change Canada.

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Source: Environment and Climate Change Canada.

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Defining non-point and point sources

Sources of phosphorus entering Lake Erie are generally considered to be either point sources or non-point sources.

Point sources include, for example, municipal and industrial wastewater treatment plants. They tend to be measured on a regular basis and their variability is relatively low because treatment processes are controlled, resulting in discharges with a fairly constant quality.

Non-point sources include, for example, agricultural and stormwater runoff. They are highly variable in quality and quantity over the course of a year and loads are more difficult to measure.

Wastewater treatment levels

Primary treatment involves the retention of wastewater to allow some settling of solids.

Secondary treatment uses biological processes and additional settling to remove dissolved organic compounds that escape primary treatment.

Tertiary treatment uses specialized processes to further improve effluent quality including enhanced phosphorus removal.

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Working together to save Lake Erie

During the development of this action plan, Canada and Ontario established a multi-sectoral Lake Erie Nutrients Working Group, and also engaged Indigenous  communities, municipalities, conservation authorities, environmental organizations, members of the agricultural community, and the public.

Early actions and a draft plan were posted online in October 2016 and March 2017, respectively, to gather additional feedback from the public, partners and stakeholders. Significant input was also gathered through in-person engagement sessions and written submissions.

The feedback gathered was used to enhance the plan with new partner-led actions added to the existing Canada-Ontario actions in cases where a partner is committed to playing a significant role.

Notwithstanding the formal partner commitments mentioned above, Canada and Ontario recognize that successful implementation of all the actions in this plan rely on the ongoing work being done by their many partners across the Lake Erie basin.

Table 1: summary of the actions in the Lake Erie action plan by category

Goal: Reduce Canadian phosphorus loadings by 40 per cent
Category of action Actions
A. Reduce phosphorus loadings

A1. Support watershed and nearshore-based strategies and community-based planning for reducing phosphorus loadings

A2. Reduce phosphorus loadings from urban areas

A3. Reduce phosphorus loadings from agricultural and rural areas

B. Ensure effective policies, programs and legislation

B1. Support and strengthen policies, programs and legislation

B2. Strengthen decision-making tools

C. Improve the knowledge base

C1. Conduct monitoring and modelling

C2. Conduct research to better understand nutrient dynamics in the Lake Erie basin

C3. Conduct research to better understand and predict the impact of climate change on the Lake Erie ecosystem

C4. Conduct research to improve existing practices and develop new innovative practices and technologies to reduce phosphorus loadings

D. Educate and build awareness

D1. Enhance communication and outreach to build awareness, improve understanding and influence change

D2. Share data and information

E. Strengthen leadership and co‑ordination

E1. Improve communication and co-ordination

E2. Establish an adaptive management framework and governance structure for implementation

Watershed planning

Watershed planning is encouraged across the province through the Provincial Policy Statement (2014).  Under the Growth Plan for the Greater Golden Horseshoe (2017), municipalities are required to undertake watershed planning to help inform land use and infrastructure planning, decision making, and to protect water.  Ontario is also developing guidance to support watershed planning that will be completed in 2018.

Optimizing wastewater infrastructure

The Ontario Ministry of the Environment and Climate Change (MOECC) and the Grand River Conservation Authority are partnering with municipalities to deliver the Grand River Watershed-wide Wastewater Optimization Program. This program provides assistance to municipalities to optimize their wastewater treatment plants and improve effluent quality.

Participants are aiming to achieve voluntary targets for phosphorus and ammonia beyond legal requirements. These targets are based on the Grand River Water Management Plan, which recommends voluntary total phosphorus and total ammonia nitrogen targets for municipal wastewater treatment plants in the watershed. For example, through optimization, the City of Brantford’s secondary treatment plant is achieving 0.2 milligrams per litre or less total phosphorus in effluent (which approaches the performance of chemically assisted filtration). Brantford has reduced total phosphorus and total ammonia nitrogen by 94 per cent and 56 per cent, respectively, and saved $27.8 million in budgeted plant upgrades since initiating its optimization program in 2011.

Other municipalities pursuing optimization in the Grand River watershed include the County of Brant, the City of Guelph, Haldimand County, Southgate, the Region of Waterloo, Centre Wellington and Wellington North.

In addition to the Grand River program, the MOECC is piloting a wastewater treatment optimization program in southwest Ontario that includes the Municipalities of Chatham-Kent and Leamington, the Town of Kingsville, and the Cities of Sarnia and Windsor.

Reducing the impact of greenhouses on the Great Lakes

To help the province’s agriculture sector reduce phosphorus discharges and drive water quality improvements, Ontario initiated a greenhouse environmental compliance plan that includes support for education and awareness, information on new technologies, annual water monitoring activities, and inspections.

Ontario’s ongoing engagement with the greenhouse sector has led to a new Greenhouse Nutrient Feedwater Regulation, which came into effect in 2015. To drive water quality improvements, the greenhouse environmental compliance plan places a priority focus on greenhouses that discharge into Leamington area tributaries or the Thames River watershed. All greenhouses across the province are required to take action to implement solutions to manage nutrients in each greenhouse, and must apply for any necessary provincial approvals for discharging into the natural environment. The Ministry of the Environment and Climate Change is employing voluntary and mandatory abatement tools to promote compliance.

Leveraging investment for healthy watersheds

For more than 40 years, the Lake Erie Conservation Authorities’ Healthy Watershed programs have provided technical assistance and financial incentives to improve and protect water quality. Collectively, these programs have offered grants for best management practices, in some circumstances up to 100 percent of the cost; including conservation farm practices, clean water diversion, erosion control, buffer strips, rock chutes, stream fencing, tree planting, wetland creation, well decommissioning, septic improvements, cover crops and more.

These programs have been very effective, flexible and strategic, and designed to address local watershed issues with local partners. Since 2012, more than $30 million has been granted to fund more than 8,350 projects in Lake Erie watersheds. Funding for the programs has been the result of Conservation Authorities’ ability to leverage local funds and partnerships with municipal, provincial and federal funding, when available.

A sampling of the science informing this plan

Ontario has undertaken several monitoring and research studies as part of its Great Lakes Nearshore Monitoring Program. These include tracking the influence of the Grand River in the nearshore of Lake Erie’s eastern basin (2010), investigating the impacts and causes of the 2012 fish kill along the north shore of the central basin, and monitoring the extent and causes of harmful algal blooms along the shoreline of the western and central basins (2013).

Canada, through its Great Lakes Nutrient Initiative, has made significant investments in monitoring to improve our understanding of phosphorus loadings from Canadian tributaries and the health of biota and water quality conditions in the nearshore of Lake Erie. Models have been developed to help set phosphorus load reduction targets and to improve understanding of the linkages between land use and phosphorus loadings to tributaries and, ultimately, Lake Erie.

Federal and provincial plans to address climate change

Published in 2016, Ontario’s Climate Change Action Plan is a five-year plan that outlines specific actions to help Ontario households and businesses reduce harmful greenhouse gas pollution.

Also in 2016, the federal government worked with provincial and territorial governments to develop the Pan-Canadian Framework on Clean Growth and Climate Change, which outlines the Government of Canada’s commitment and plan to reduce greenhouse gas emissions and build resilience to adapt to a changing climate.

The framework builds on the actions taken individually and collectively by provinces and territories, and works to ensure Canadians are engaged in order to strengthen and deepen action on clean growth and climate change. The plan includes a pan-Canadian approach to carbon pricing, measures to reduce greenhouse gas emissions in all sectors, adaptation to climate impacts, and increased technology development and adoption to help Canada move toward a low-carbon economy.

Ongoing research on phosphorus loading reduction technologies and practices

Canada and Ontario continue to invest in research and demonstration initiatives to improve knowledge and understanding of the effectiveness of BMPs for reducing nutrient loss and improving nutrient and water use efficiency in agriculture production. This ongoing research will inform government and the agriculture sector of which actions will lead to the largest reduction in phosphorus loss. Canada and Ontario have also provided funding to demonstrate greenhouse nutrient feedwater recycling, which has led to the adoption of new technologies and reduction of phosphorus loadings to the environment.

One of the most promising research areas relates to the development of innovative practices to capture and store, and in some cases, recover phosphorus from point and non-point sources. In support, Ontario has partnered on an innovative technology competition (the George Barley Water Prize) to reduce and recover phosphorus from water bodies and will host the pilot stage in Ontario to demonstrate cold climate application. Ontario has taken action to maintain its regulation-making authority (under the Ontario Water Resources Act) that enables water quality trading as a potential future tool for managing phosphorus.

Agriculture sector peer-to-peer initiative

Ontario’s farm community is taking action to inform producers about the potential risks associated with spreading nutrients on frozen or snow-covered ground, including the risk this poses to downstream waters.

The Timing Matters Peer Response Team is a peer-to-peer network made of a coalition of farm organizations. The team is listening to help farmers identify practical alternatives to spreading nutrients in the winter on frozen or snow-covered ground, in order to use nutrients more effectively and minimize potential environmental impact on local creeks, rivers and lakes. The emphasis of the team is to remind producers of the risks of nutrient runoff in spring thaw waters resulting from nutrient spreading on frozen or snow-covered ground.

What does Lake Erie need right now?

People will ask,
What’s wrong with Lake Erie?
And what can we do?

What will we tell them?
The more we learn about water
The more obvious it appears
That there is no simple answer
But the right questions make things clear

Excerpt from Aquahacking Youth Delegation Poem (June 2017)

Performance measures for adaptive management

Performance measures track the progress of actions being taken and assess phosphorus loads and water quality to determine the effects of those actions. This information is used to guide management decisions.

For this action plan, the following categories of performance measures will be monitored and reported on:

  • reductions to phosphorus loadings
  • improvements to lake water quality — blooms, oxygen levels, attached algal growth
  • changes to land use and land cover — urban, agricultural, naturalized areas and wetlands
  • adoption of agricultural best/beneficial management practices (BMPs) — nutrient management, modeling to assess change in risk of phosphorus loss, measures to manage wastewater
  • adoption of municipal BMPs —reduction in loads from water pollution control plants, stormwater improvements and reductions in stormwater loads

Source: Delta Stewardship Council. 2013a

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Best/beneficial management practice


Canadian Environmental Protection Act, 1999


Canada–Ontario Agreement on Great Lakes Water Quality and Ecosystem Health, 2014


Combined sewer overflow


Environmental Farm Plan


Great Lakes Agricultural Stewardship Initiative


Great Lakes Protection Act, 2015


Great Lakes Water Quality Agreement, 2012


Hydrological soil group


Low impact development


Pollution from Land Use Activities Reference Group


Priority Subwatershed Project


Wastewater treatment plant


Provincial Water Quality Monitoring Network


Adaptive management

An iterative process through which management objectives, approaches and policies can be adjusted over time for continuous improvement based on monitoring, performance measures, and evolving science and information.


Readily assimilated by plants and algae and used for growth.

Biophysical characteristics

The living and non-living environmental factors that influence the growth of biological organisms.

Best/beneficial management practices

Proven, practical and affordable approaches to conserving or protecting soil, water and other natural resources in urban and rural areas.


An attached algae species that can cause dense mats in standing water, clogging intake pipes as well as fouling shorelines and shing equipment. Cladophora is the primary cause of nuisance algal blooms in Lake Erie’s eastern basin.

Combined sewer overflow

A discharge to the environment from a combined sewer system (a single pipe system of sewers that carry both sanitary sewage and stormwater runoff) that usually occurs as a result of a precipitation event when the carrying capacity of the system is exceeded. Combined sewer overflows can contain high levels
of floatables, pathogenic microorganisms, suspended solids, oxygen-demanding organic compounds, nutrients (including phosphorus), oil and grease, toxic contaminants and other pollutants. (Combined sewer systems are designed to allow overflows following intense precipitation events to protect residential, commercial and industrial property from sewer backups.)


The mass of a substance present in a given volume of water expressed in units such as milligrams per litre.


Also called blue-green algae, a type of bacteria that undergoes photosynthesis and thus can be influenced by excessive phosphorus concentrations. An example is Microcystis. Cyanobacteria can produce toxic substances — called cyanotoxins — with the potential to harm humans and other organisms.


Toxic biological compounds produced by cyanobacteria such as Microcystis, which produce the toxin microcystin. Cyanotoxins have potentially signicant human health consequences if ingested or through skin exposure and may also be toxic to other organisms.

Dreissenid mussels

A collective term used for zebra and quagga mussels, which are non-native, invasive species in the Great Lakes basin.

Ecosystem components

Biological organisms and the non-living parts of the environment in which they live (e.g., fish, plants, air, water, soil).

Ecosystem services

The natural services provided by a healthy ecosystem. These include provisioning services such as production of food, fiber, timber, oxygen and water; production of pharmaceutical, biochemical and industrial raw materials; regulating services including climate regulation, flood and erosion control, water and air purification, and absorption and storage of gases; ecosystem support services including soil formation, photosynthesis and nutrient cycling, pollinating crops and plants, and dispersing seeds; and cultural services such as creating intellectual, artistic and recreational opportunities, aesthetic enjoyment and spiritual fulllment.


Discharge from municipal or industrial wastewater treatment plants following treatment.


The oxygen-rich upper layer of water in a stratied lake; see stratication.


Excess nutrient enrichment causing nuisance and harmful algal blooms that in turn can cause low dissolved oxygen levels and associated fish kills.

Extreme weather event

A weather event that is unexpected, unusual, severe or unseasonal. Weather at the upper or lower extremes of the historical distribution (typically a 30-year period).

Food web

The natural connections between species — what eats what — in a biological community.

Green infrastructure

Natural and human-made elements that provide ecological and hydrological functions and processes. Green infrastructure can include components such as natural heritage features and systems, parklands, stormwater management systems, street trees, urban forests, natural channels, engineered wetlands, bioswales, permeable surfaces and green roofs.

Harmful algal blooms

See cyanobacteria.

Hauled sewage

Hauled sewage (or “septage”) is untreated waste material removed from portable toilets, sewage holding tanks and septic systems.

Huron-Erie corridor

The flows from Lake Huron through the St. Clair River, Lake St. Clair and the Detroit River. Flows from the Huron-Erie corridor discharge into Lake Erie’s western basin.


The bottom layer of water in a stratified lake. In the summer, the hypolimnion is colder than surface waters. In the winter, surface waters are frozen or close to freezing, while the hypolimnion is somewhat warmer — typically a few degrees above freezing. The hypolimnion can experience low levels of dissolved oxygen under certain conditions; see stratification.


An area with low levels of oxygen. Late summer hypoxia — the reduction of oxygen to less than two parts per million — occurs naturally in Lake Erie’s central basin due to the stratification of layers by temperature, with the warmer layers on top.

Lakewide Action and Management Plan

Established under the Canada–U.S. Great Lakes Water Quality Agreement, 2012, these are lake-specific binational action plans for restoring and protecting Great Lakes ecosystems.

Legacy sources

Phosphorus from past activities contained in biological tissues as well as in sediments in lake and stream beds, flood plains and agricultural fields. Legacy sources of phosphorus can be re-mobilized and add to loadings even when current practices are geared to phosphorus reduction.


The total mass of a substance delivered to a water body over time expressed in units of mass per unit time, such as tonnes per year. Load is the product of concentration (mass per unit volume) and flow rate (water volume per unit time).

Low impact development

Urban stormwater management measures that seek to retain rainwater on the site through collection and infiltration. Examples include rain barrels, green roofs, infiltration trenches, rain gardens and permeable pavement.


A genus of cyanobacteria, known to produce the toxin microcystin.


Toxins produced by cyanobacteria.

Multi-barrier approach

For this action plan, “multi-barrier” refers to a systems-based approach that implements multiple management practices that work together to reduce phosphorus loading from source to receiving water body.

Natural heritage features

The green infrastructure of the natural environment; see green infrastructure. Natural heritage means features and areas — including wetlands; coastal wetlands; habits of fish, wildlife, threatened species and endangered species; woodlands and valleylands; and areas of natural and scientific interest — that are important due to their environmental and social values as a legacy of the natural landscapes of an area.

Non-point source

Sources of pollution that are many and diffuse, in contrast to point source pollution, which results from a single source. Non-point source pollution generally results from land runoff, precipitation, atmospheric deposition, drainage, seepage or hydrological modification where tracing the pollution back to a single source is difficult.

Nuisance algal blooms

Blooms of algae such as Cladophora that can cause fish kills (see eutrophication), degrade fish and wildlife habitat, clog water intake pipes, and foul shorelines and fishing equipment but which do not produce toxins.

Nutrient cycling

The natural movement and transformation of nutrients such as phosphorus through soil, water and air, and in different chemical forms.

Point source

Sources of pollution that enter a water body through a pipe or similar outlet, such as a municipal or industrial wastewater treatment plant discharge. Point sources have usually undergone some level of treatment before discharge; an exception is most combined sewer overflows.

Riparian zone

The area of land adjacent to tributaries and the lake where vegetation may be influenced by flooding or elevated water tables. A healthy riparian zone provides habitat for a variety of aquatic and terrestrial species. Its complex vegetative structure protects against erosion and can control the runoff of sediment, phosphorus and other pollutants, reducing impacts on water quality under certain conditions.


The flow of water that occurs when excess stormwater, meltwater or other sources flow over the Earth’s surface. This might occur because soil is saturated to full capacity, rain arrives more quickly than soil can absorb it or impervious areas send their runoff to surrounding soil that cannot absorb all of it. Surface runoff is a major component of the water cycle and the primary agent in soil erosion by water.

Soluble reactive phosphorus

Phosphorus in dissolved form. The term “reactive” refers to the reaction of phosphorus with a colour agent during the analysis of phosphate concentrations in a laboratory.


Water that originates during precipitation events and snow or ice melt. Stormwater can soak into the soil, be held on the surface and evaporate, or run off and end up in nearby streams, rivers and other water bodies.


The formation of layers in a lake — typically a well-mixed, warmer, oxygen-rich surface layer (epilimnion); a transitional zone (metalimnion or thermocline); and deeper, colder waters that can become oxygen-poor (hypolimnion). Strong winds in spring and fall thoroughly mix the waters of all but the deepest lakes. Stratification occurs in the summer, with a warm layer at the surface overlying colder waters, and in the winter, where colder waters or ice overlie somewhat warmer waters at depth. Shallow lakes may never stratify, or stratification may not persist.


Lands that are seasonally or permanently covered by shallow water, as well as lands where the water table is close to or at the surface. In either case, the presence of abundant water has caused the formation of hydric soils and has favoured the dominance of either hydrophytic plants or water-tolerant plants. The four major types of wetlands are swamps, marshes, bogs and fens.

Whole-farm approach

An approach that considers an entire farming operation. A whole-farm approach considers a farm’s production type (e.g., cropping, livestock), biophysical characteristics (e.g., soil type, slope, proximity to water, woodlots), infrastructure (e.g., wells, manure storages, barns), biodiversity (e.g., wildlife) and management (e.g., nutrient management planning). This approach also seeks to balance these aspects to operate a financially viable operation for the long-term.

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