Ausable Bayfield Conservation Authority



This page is in development. These definitions are provisional, provided here only for local information purposes for use in conjunction with the website. In some cases, some definitions are from other sources and should not be referenced from this location but should be searched at their original location. These are not legal definitions or official definitions for the purpose of decision-making. This glossary is subject to review and update.

Abandoned well

An abandoned well has been deserted – perhaps because it has been replaced by another source of drinking water or because it is dry, contains non-potable water, was discontinued before completion, has not been properly maintained, was constructed poorly, or is susceptible to contamination. Abandoned wells can provide pathways for surface water to contaminate groundwater sources – for this reason they should be properly decommissioned and capped.


The conversion of land, not previously forested, to forested land through human activities such as planting, seeding.

Algal bloom

An algal bloom refers to rapid and/or prolific growth of small aquatic plants on the surface of lakes and rivers, usually as a result of excessive nutrients.

Area of Natural and Scientific Interest (ANSI)

Area of land and water containing natural landscapes or features that have been identified as having life science or earth science values related to protection, science or earth science values related to protection, scientific study or education.


Area Of, or concerning water; An organism which has its main habitat for growth, reproduction, and survival in water or partially submerged in water.


An aquifer is an underground rock formation or structure that carries water. The water in an aquifer is called groundwater. An aquifer is an underground area of porous, permeable soil or rock – almost like a sponge – that has enough water inside it to support a well. Shallow aquifers exist in the overburden, the sedimentary rock and soil above bedrock. Bedrock aquifers are found in the bedrock itself, under overburden. A water-bearing layer (or several layers) of rock or sediment capable of yielding supplies of water; typically consists of unconsolidated deposits of sandstone, limestone or granite, and can be classified as confined, unconfined or perched.


An aquitard is a layer of geological material that prevents or slows the transmission of water in a confined aquifer. It is a confining bed and/or formation composed of rock or sediment that slows but does not prevent the flow of water to or from an adjacent aquifer. It does not readily yield water to wells or springs, but stores groundwater. It is a layer of geologic material with little to no permeability or hydraulic conductivity that functions as a container for an aquifer. Water does not rapidly pass through this layer or the rate of movement is extremely slow. See also ‘confining layer.’


Baseflow is the amount of water in a watercourse that comes from groundwater. Baseflow is the water that flows into a stream through the subsurface. It is the sustained flow (amount of water) in a stream that comes from groundwater discharge or seepage. Groundwater flows underground until the water table intersects the land surface and the flowing water becomes surface water in the form of springs, streams/rivers, lakes and wetlands. Baseflow is the continual contribution of groundwater to watercourses and is important for maintaining flow in streams and rivers between rainstorms and in winter conditions.


Basin is the area drained by a river or a watershed with a common outlet.


Bedrock is the solid rock underlying unconsolidated surface material. Solid or fractured rock is usually underlying unconsolidated geologic materials; bedrock may be exposed at the land surface.


Benthic means occurring at the bed or base of watercourses (e.g., streams, rivers, and other bodies of water such as lakes, oceans and seas). Benthic Invertebrates Benthic invertebrates are small aquatic organisms that live in stream sediments and are a good indicator of water quality and stream health. Benthic invertebrate assemblages are reflective of not only water chemistry, but also substrate (i.e., stream bottom) conditions (Lammert and Allan 1999; Richards et al. 1993; de March 1976). Substrate conditions vary across watersheds and therefore efforts were made to be as consistent as possible when sampling benthic sites. Sampling sites for the watershed report card process were of the highest quality substrate that supports the best possible invertebrate communities. Benthic invertebrate scores indicate that animals that are tolerant to organic pollution dominated the communities. Common species that were found in the ABCA area include worms, riffle beetles and some insects that are tolerant to nutrient enriched conditions. Sites in the Middle Ausable and Mud Creek watersheds appeared to be more degraded than most other sites in this area. Benthic invertebrates are small animals, without backbones, that live in stream sediments.

Benthic macroinvertebrates

Benthic macroinvertebrates are commonly used as indicators of aquatic environmental quality. ‘Benthic’ refers to the bottom of lakes and rivers whereas ‘macro’ refers to the subset of larger or visible invertebrates: generally ¼ to ½ mm in length. Invertebrates are animals without backbones such as insects, crustaceans, molluscs, and worms.

Benthic region

The benthic region is the bottom of a body of water, supporting the benthos.


Benthos is the plant and animal life whose habitat is the bottom of a body of water.


A berm is a narrow shelf or ledge that can be used at the bottom of a slope to reinforce and stabilize it against slumping and erosion or to direct overland flow. A berm can be a linear mound of earth, or raised barrier, that separates two areas.

Best management practices (BMPs)

Best management practices – or beneficial management practices – are structural, non-structural and managerial techniques that are recognized to be the most effective and practical means to control non-point source pollutants yet are compatible with the productive use of the resource to which they are applied. BMPs are used in both urban and rural areas including farm and non-farm land. A proven, practical and affordable approach to conserving soil, water and other natural resources.

Biochemical oxygen demand (BOD)

Biochemical oxygen demand (BOD) is a measure of the quantity of oxygen used by micro-organisms (e.g., aerobic bacteria) in the decomposition (oxidation) of organic solids. It is a measurement used to assess the rate at which water is deoxygenated. High BOD general corresponds to water containing high amounts of organic pollution.

Biological diversity

Biological diversity is the variability among organisms and the ecological complexes of which they are a part.


Biomass is the amount of living matter, usually measured per unit area or volume of habitat. Biosphere The biosphere is all living organisms (plant and animal life).


Biotic is relating to or caused by living beings. Biotransformation Biotransformation is the conversion of a substance into other components by organisms; includes ‘biodegradation.’


A bluff occurs where those actions of the shoreline formed in non-cohesive or cohesive sediments where the land rises steeply away from the water such that the elevation of the top of the slope above the base or toe of the slope is greater than a set amount (for instance, two metres and the average slope angle exceeds 1:3 or 18 degrees).


Bogs are peat-covered areas or peat-filled depressions with a high water table and a surface carpet of mosses, chiefly sphagnum. The water table is at or near the surface in the spring, and slightly below during the remainder of the year. The mosses often form raised hummocks, separated by low, wet interstices. The bog surface is often raised, or, if flat or level with the surrounding wetlands, it is virtually isolated from mineral soil waters. Hence, the surface bog waters and peat are strongly acid and upper peat layers are extremely deficient in mineral nutrients. The surface of the bog may often be raised above the surrounding terrain. Bogs are isolated from mineral-rich soil waters, therefore nutrient input is from atmospheric deposition. They are strongly acidic and nutrient poor. Peat is usually greater than 40 centimetres deep. Groundcover is usually moss, Sphagnum spp. and ericaceous shrubs and may be treed or treeless. Bog water is derived from groundwater or precipitation.

Carolinian Zone

The southernmost part of the Province of Ontario, generally considered to lie south of a line drawn between Toronto and Grand Bend. It contains more endangered and rare species of plants and animals than any other part of Canada.


The area between the banks of a stream where water normally flows.

Channel capacity

Channel capacity is the ability of a watercourse at a given cross-section to convey flows of water, or how much water can be carried at a particular place. Floods occur when the channel capacity is Channelization The smooth realignment and regarding of a creek or stream bed; implies modification of the watercourse to increase channel capacity; channelized banks are usually reinforced with stone or concrete rip-rap.


Chemicals include some ingredients in solvents, fuels, fertilizers, pesticides and similar products. They may be found in factories, storage depots, gasoline stations, farms or other sites.


Chloride is a naturally occurring element that can be found at high concentrations (i.e., greater than the drinking water quality standards) under natural circumstances. The concentration of chloride in groundwater can be related to the type of rock the groundwater is coming from. Typically sedimentary rocks (e.g., evaporates) have higher concentrations of chloride.


The historical record and description of average daily and in seasonal weather events that help describe a region. Statistics are generally drawn over several decades. Climatology, or the study of climate, includes climatic data, the analysis of the causes of the differences in climate, and the application of climatic data to the solution of specific design or operational problems. It differs from weather, which is concerned with short term or instantaneous variations in the state of the atmosphere at a specific time. (Environment and Climate Change Canada).

Climate change

Climate change is a significant shift in long-term average weather patterns, which can include changes in temperature, precipitation and wind patterns. Changes to our climate last for an extended period of time and can reflect a combination of natural and human impacts. There is broad agreement in the scientific community that human activities are altering the chemical composition of the atmosphere through the build-up of greenhouse gases that trap heat and reflect it back to the earth’s surface – resulting in changes to our climate, including a rise in global temperatures and more frequent extreme weather events.

Climate variability

Climate variability, or ‘climatic variability,’ refers to temporal variations of the atmosphere for periods of time longer than those associated with normal weather events. The term ‘natural climate variability’ is used to identify climate variations not attributable to or influenced by human activity. Climate variability refers to the normal ups and downs (warm periods, cool periods, wet periods, dry periods). Climate variability may be in the form of cycles, major floods (25 year) and major droughts (30 years). Climate change may amplify these extremes.


Bacteria found only in human and animal wastes; presence in a river indicates pollution by sewage or runoff. Coliforms are bacteria found only in human and animal wastes. Presence in a river may indicate pollution by sewage or runoff. Coliforms are threats to human health and may be indicators of the presence of other pathogen contaminants.

Cold water

Cold water is water with a temperature of about 14 C. This thermal habitat is typically considered ideal for brook and brown trout.

Confined aquifer

Confined aquifer is also commonly called an artesian aquifer. A confined aquifer is bounded above and perhaps below by layers of geological material that do not transmit water readily. It is the saturated formation between impermeable layers that restrict movement of water vertically into or out of the saturated formation. In this layer, water is confined under pressure, similar to water in a pipeline. Drilling a well into this type of aquifer is similar to puncturing a pressurized pipeline. If the pressure is great enough, the well will flow, and this is called a flowing artesian well. A confined aquifer is an aquifer that is bounded above, and perhaps below, by layers of geological material that don’t easily transmit water. See also ‘aquitard.’


The wise use and protection of our natural resources. Conservation is the wise use of natural resources including the protection of natural or human-made resources and landscapes for later use.

Conservation authority

A community based environmental protection agency. A conservation authority is a natural resource management agency, guided by a board of directors made up of local municipal representatives, having jurisdiction over a watershed and operated according to the Conservation Authorities Act. Conservation authorities are local watershed management agencies that deliver services and programs that protect and manage water and other natural resources in partnership with government, landowners and other organizations. They have legal responsibilities and powers under the Conservation Authorities Act and other legislation.

Conservation lands

Conservation lands are lands which are considered to be regionally significant, such as valleys or environmentally sensitive areas, and are best managed by a public agency to retain their natural characteristics.

Conservation strategy

A conservation strategy is an overall policy and development statement covering all aspects of a conservation authority’s work. Thirty-four people from the Ausable Bayfield community took part in a year-long project that resulted in a Conservation Strategy for this watershed area, including a new vision, mission, motto/tagline, logo, and long-term actions to create a healthy watershed. Conservation Ontario The umbrella organization that represents Ontario’s 36 conservation authorities.

Contaminant (pollutant)

A contaminant is an undesirable substance that makes water unfit for a given use when found in sufficient concentration. Chemicals, pathogens and dense non-aqueous phase liquids are types of substances that can contaminate water.


Contamination is the mixing of harmful elements, compounds or microorganisms with surface or groundwater. Contamination can occur naturally (e.g., an aquifer flowing through mineral deposits that contain heavy metals) or through human activity (e.g., sewer water flowing into a river). Nutrients, such as nitrogen and phosphorus, can also cause water contamination when they are present in excessive amounts.


A large pipe or tube that allows water to flow under a road or driveway.


The force of moving water.


A barrier set across a river to control the flow of water. A dam is a structure used to hold back water.

Data gaps

Data gaps indicate the lack of site-specific information for a geological area and/or specific type of information.

Decommissioned wells

Decommissioned wells are capped, plugged and sealed in compliance with regulatory requirements by the Ontario Ministry of the Environment. Decommissioning a well can prevent contamination by closing a potential pathway by which surface water can contaminate groundwater.


Discharge is the flow of surface water in a stream or canal, or the outflow of groundwater to a well, ditch or spring. It is the volume of water in cubic metres per second (m3/s) running in a watercourse.

Discharge area

A discharge area is an area where water leaves the saturated zone across the water table surface. It is an area where groundwater emerges at the surface and where upward pressure or hydraulic head moves groundwater towards the surface to escape as a spring, seep, or base flow of a stream.


A diversion is a redirection of water from one drainage or watercourse to another. Diversions of the Ausable River The Ausable River has had two diversions. The first, ‘The Cut,’ was dug in the 1870s. This channel south of Pinery Provincial Park bypassed the original loop through Grand Bend and drained shallow lagoons in the Thedford Marsh. In 1892, the second diversion routed Parkhill Creek, the remaining flow in the loop, straight west to Lake Huron at Grand Bend. The two diversions isolated the original Ausable River between Grand Bend and ‘The Cut,’ restricting the Old Ausable Channel to local drainage. Drilled well A drilled well usually 10 inches or less in diameter, drilled with a drilling rig and cased with steel or plastic pipe. Drilled wells can be of varying depth.


Ecological relates to the totality or pattern relations between organisms and theirenvironment.


Ecology is an interdependent community of plants and animals living in a recognizablearea. Humans are a major part of most ecosystems.


An ecosystem is the natural community of plants and animals within a particular physical environment, which is linked by a flow of materials throughout the non-living (abiotic) as well as the living (biotic) section of the system.

Ecosystem Approach

The ecosystem approach is a holistic way of planning and managing natural resources; it means that the consequences of an action (including the cumulative effect of many small actions) on all other parts of the ecosystem will be considered and evaluated before the action is undertaken.


Effluent is the discharge of a pollutant in a liquid form, often from a pipe into a stream or river. Enhancement Enhancement is to add to, or to make greater. For example, to add additional water to a wetland, in order to make greater its environmental functionality, would be an enhancement.


Erosion is the wearing away of the land by the action of water, wind or glacial ice. It is a physical process causing the deterioration and transport of soil surfaces and river channel materials by the force of flowing water or wind, ice or other geological agents, including such processes as gravitational creep. Geological erosion is naturally occurring erosion over long periods of time.

Escherichia coli (E. coli)

Escherichia coli (E. coli) are pathogens, or types of bacteria, found in human and animal waste. Their presence in water indicates the potential presence of fecal contamination or other harmful pathogens. Their presence in water indicates a potential for the water to have other disease-causing organisms. E. coli are bacteria found in human and animal waste. Their presence indicates water may contain other disease-causing organisms. Different strains of E. coli pose different levels of hazards to human health. The 0157:HT strain is a significant hazard to human health.

Fecal coliform and Escherichia coli (E. coli) are bacteria. Escherichia coli are bacteria that normally inhabit the large intestines of humans and other mammals. Most E. coli bacteria are harmless to healthy humans and do not cause disease. However, some forms of E. coli cause disease through the intestines. More than 2,300 people became ill and seven people died when the drinking water system in Walkerton, Ontario became contaminated in May of 2000. The well system was contaminated with deadly bacteria: primarily Escherichia coli O157:H7.1 as well as Campylobacter jejuni.  Studies on E. coli O157:H7 in various soil types show that these pathogens survive at least 10 to 25 weeks. 

Escherichia coli are bacteria found in the gut of warm-blooded animals – and in the waste of humans and animals. Their presence in water indicates fecal contamination, a threat to human health and the potential that water may have other disease-causing organisms. There are numerous strains of Escherichia coli. Some are found in the human gastrointestinal tract. Others are responsible for diarrhea or other diseases, including illness and sometimes death. Testing for E. coli is often done as an indicator of other organisms which may be present.

E. coli O157:H7, a subgroup of E. coli, produces verotoxins that cause hemorrhagic colitis and, in some cases, hemolytic uremic syndrome (HUS). HUS is life-threatening. A person infected with E. coli O157:H7 can experience intestinal disease marked by diarrhea usually lasting about four days or more. Bloody diarrhea often occurs 24 hours after someone gets the illness. The infected person may experience severe abdominal pain.  E. coli O157:H7 infection can have very serious consquences to the elderly and to children under five years of age.

Verotoxins produced by E. coli O157:H7 can cause acute kidney failure, anemia, and low platelet counts, according to the Report of the Walkerton Inquiry. Verotoxin produced by E. coli O157:H7 can also affect small blood vessels in the brain.  For more information visit the Walkerton Inquiry.  


An interacting system of living organisms and their environment.

Environmental Farm Plan (EFP)

Environmental Farm Plans are assessments voluntarily prepared by farmers in order to highlight their farm’s environmental strengths, identify areas of environmental concern, and set realistic action plans with time tables to improve environmental conditions. Environmental cost-share programs are available to assist in implementing projects.

Environmentally Significant Area (ESA)

Ausable Bayfield Conservation defines Environmentally Significant Areas as areas of woodlots that contain some wetland features that play an important role in supporting significant plant or animal species and/or serving hydrological functions. A site may also be significant if it supports a remnant or a threatened species of flora or fauna.


The movement of soil by wind, water or ice.


Eutrophication is generally associated with increased plant productivity due to increased nutrient presence, mainly phosphorus, and sometimes nitrate concentrations in lakes, streams, rivers or other water bodies. Sources such as run-off can contribute to the presence of phosphorus or nitrates. Nutrients can contribute to the growth of algae, weeds or other nuisance plants. The growth of algae, or algal blooms, lowers dissolved oxygen in the water. Other organisms can die as plants decompose.

Eutrophic lakes

Eutrophic lakes are lakes that are rich in nutrients and organic materials, therefore highly productive for plant growth. These lakes are often shallow and seasonally deficient in oxygen in the hypolimnion.


The process by which water turns into a gas and goes to the sky. Evaporation is the process by which water or other liquids change from liquid to vapour; evaporation can return infiltrated water to the atmosphere from upper soil layers before it reaches groundwater or surface water, and occur from leaf surfaces (interception), water bodies (lakes, streams, wetlands, oceans), and small puddled depressions in the landscape.


Evapotranspiration is the combined loss of water from a given area and during a specific period of time by evaporation from the soil surface and by transpiration from plants.

Family Biotic Index (FBI)

An index used to provide an evaluation of stream health based on pollution tolerance scores for families of benthic macroinvertebrates. Family Biotic Index (FBI) summarizes the numbers and types of these animals in a sediment sample. Values reflect stream health, ranging from 1 (healthy) to 10 (degraded).


Fens are peatlands characterized by surface layers of poorly to moderately decomposed peat, often with well-decomposed peat near the base. The waters and peat in fens are less acid than in bogs, and often are relatively nutrient rich and minerotrophic since they receive water through groundwater discharge from adjacent uplands. Fens usually develop in situations of restricted drainage where oxygen saturation is relatively low and mineral supply is restricted. Usually very slow internal drainage occurs through seepage down very low gradient slopes, although sheet surface flow may occur during spring melt or periods of heavy precipitation or if a major local or regional aquifer discharges into the wetland. Some fen wetlands develop directly on limestone rock where minerotrophic waters are emerging through constant groundwater discharge.


Fill is the rubble, earth, rocks or other imported material that is used to raise or alter the existing elevation.


The overflowing of water in a river onto the flood plain.

A flood is an overflow or inundation that comes from a river or other body of water and causes or threatens damage. It can be any relatively high streamflow overtopping the natural or artificial banks in any reach of a stream. It is also a relatively high flow as measured by either gauge height or discharge quantity.

Flood plain

The flat land beside a watercourse that periodically becomes covered by water; the river's living space.

Flood plain is the area bordering a river, which has been formed from deposits of sediment carried down the river. When a river rises and overflows its banks, the water spreads over the floodplain. It is a strip of relatively level land bordering a stream or river. It is built of sediment carried by the stream and dropped when the water has flooded the area. It is called a water floodplain if it is overflowed in times of high water, or a fossil floodplain if it is beyond the reach of the highest flood.


Floodway is the channel of a river and those parts of the adjacent floodplain which are required to carry and discharge flood water.


Flow is the volumetric rate of water discharged from a source, given in volume with respect to time. Measured in cubic metres per second. See ‘discharge.’

Flood warning system

The flood warming system is a service provided by conservation authorities to member municipalities forewarning of potential flooding situations.

Forest cover

Forest cover is the percentage of the watershed that is forested. Environment Canada recommends 30 per cent of a watershed should be in forest cover.

Forest conditions

Forest conditions include percentage of forest cover and forest interior. Forest conditions relate to the health and extent of a forest based on ecological indicators and other parameters including assessment by professionals and community stakeholders.

Forest interior

Forest interior is the portion of a woodlot which remains when a 100-metre buffer is removed from the inside perimeter (e.g., 100 metres from the outside edge). It is the area inside a woodlot that some bird species need for breeding. Environment Canada recommends 10% of a watershed should be in forest cover that is at least 100 m from the forest edge. Forest interior is the percentage of a watershed with forest cover that is at least 100 metres from the forest’s edge.

Forest management

Forest management is the intelligent use and control of the forest and its products for a specific purpose; may be for wood production, wildlife habitat, maple syrup, nature trails or any combination of these uses and others.


A great increase in the amount of water in a stream caused by heavy rains or melting snow, usually in the spring.

Fresh water

Fresh water is water with less than 1,000 milligrams per litre (mg/L) of dissolved solids. More than 500 milligrams per litre is undesirable as a drinking water source or for many industrial uses.

Geographic Information Systems (GIS)

A geographic information system is a computer-based system that has the capability to input, store, retrieve, manipulate, analyze, and output geographically referenced data. GIS, or Geographic Information System(s), is an electronic map-based database management system which uses a spatial reference system for analysis and mapping purposes.


Geology is the science of the composition, structure and history of the Earth. This includes the study of the material that makes up the planet the forces which act upon these materials and the structures which are formed from this relationship. It is the study of science dealing with the origin, history, materials and structure of the earth, together with the forces and processes operating to produce change within and on the earth.

Geometric mean

The nth root of the product of all the members of the set, where n is the number of members. The geometric mean is useful to determine typical conditions.


Geomorphology is the scientific study of the origin of land, riverine and ocean features on the Earth surface. Great Lakes The Great Lakes are the five large lakes located in Canada and the United States of America: Lake Ontario; Lake Superior; Lake Huron, Lake Michigan; and Lake Erie.


Groundwater is subsurface water that occurs beneath the water table in soils and geological formations that are fully saturated. It is the water below the water table contained in void spaces (pore spaces between rock and soil particles, or bedrock fractures). It is water occurring in the zone of saturation in an aquifer or soil. It is the water found underground in the soil, wells, porous rocks, and subsurface reservoirs and channels. 

Groundwater barrier

The groundwater barrier describes rock or artificial material with a relatively low permeability that occurs (or is placed) below ground surface, where it impedes the movement of groundwater and thus may cause a pronounced difference in the hydraulic head on opposite sides of the barrier.

Groundwater basin

The groundwater basin is the underground area from which groundwater drains. The basins could be separated by geologic or hydrologic boundaries.

Groundwater discharge

Groundwater discharge is the function of a wetland to accept subsurface water and hold it for release over long periods of time.

Groundwater divide

Groundwater divide is the boundary between two adjacent groundwater basins, which is represented by a high point in the water table.

Groundwater flow

Groundwater flow is the rate of groundwater movement through the subsurface. Groundwater recharge Groundwater recharge is the inflow of water to a groundwater reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural recharge.

Groundwater recharge

Groundwater recharge is the inflow of water to a ground water reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural recharge.

Groundwater recharge area

A groundwater recharge area is an area where an aquifer is replenished from:

(a) Natural processes, such as the infiltration of rainfall and snowmelt and the seepage of surface water from lakes, streams and wetlands;

(b) From human interventions, such as the use of storm water management systems, and;

(c) whose recharge rate exceeds a specified threshold.
A significant recharge area is one of four vulnerable areas identified in Ontario’s Clean Water Act, 2006. See ‘significant recharge area.’

Groundwater vulnerability

Groundwater vulnerability is the probability of contaminants travelling to a specified region in the groundwater system after introduction at some location above the uppermost aquifer. Guideline (Water Quality) Acceptable concentrations of substances in water that is used for drinking, recreational activities, agricultural uses and the protection of aquatic life.


Habitat is an environmental area where an organism lives and the place where it is usually found. It includes the food, water, shelter, cover and other elements of the environment that living organisms need to survive.


A source of danger or risk, especially to one's personal safety.


Headwater is the source waters of a stream or river. Headwater streams Seemingly insignificant rivulets and seeps that upon convergence form recognizable streams.

Hydrologic cycle

The cycle of water movement from the atmosphere to the earth and return to the atmosphere through various stages, such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transpiration. Impermeable Impermeable means not allowing water to pass through.


A life-threatening condition in which a person's deep body temperature is lowered by exposure to cold air or water.     

Ice - Black, Grey, or Blue

Dark areas of ice that are thin and weak spots.


Impervious is a term denoting the resistance to penetration by water or plant roots. Indicator (Ecological) Indicators are measures that provide information about the state or condition of a watershed and provide a means to assess progress towards an objective or target. Watershed health indicators include surface water quality, forest conditions, and groundwater quality.


Infiltration is the movement of water into soil pores from the ground surface. Inflow Inflow is the water that flows into a lake, reservoir or forebay.

Intake protection zone

Intake protection zone (IPZ) means the area of land and water that contributes source water to a drinking water system intake within a specified distance, period of flow time (for example, two hours). A surface water intake protection zone is one of four types of vulnerable areas identified in the Ontario Clean Water Act, 2006. Intake protection zone (IPZ) means the area of land and water that contributes source water to a drinking water system intake within a specified distance, period of flow time (for example, two hours), and/or watershed area. River and lake intakes can be contaminated when dangerous materials are spilled into the water or on nearby land and make their way to the intake. Intake protection zones are areas where dangerous materials may get to an intake so quickly the operators of the municipal water treatment plant may not have enough time to shut down the intake before the pollutant reaches it.

Integrated watershed management

Integrated watershed or resource management is management of natural resources (water, trees, soil, wildlife) in a comprehensive, coordinated, cost-effective way; usually done on a watershed basis with the goal of ensuring that the resource base does not deteriorate.


Invertebrates are animals lacking a spinal column. Leachate Leachate is a liquid formed by water percolating through contaminated soil or soluble waste as in a landfill site. Loam Loam is a rich soil containing sand, silt, and clay. Lowflow Lowflow is the flow that exists in a stream channel in dry conditions.


Macroinvertebrates are animals lacking a spinal column that are visible with the unaided eye.


Marshes are wet areas periodically inundated with standing or slowly moving water, and/or permanently inundated areas characterized by robust emergents, and to a lesser extent, anchored floating plants and submergents. Surface water levels may fluctuate seasonally, with declining levels exposing drawdown zones of matted vegetation or mud flats. Standing or slow-moving water with emergent plants covering greater than 25 per cent. Permanently flooded, intermittently exposed, or seasonally flooded. Nutrient-rich water generally remains within the rooting zone for most of the growing season. Substrate is mineral soil or well-decomposed sedimentary organic material, often held together by a root mat.


Meandering is a curve in the course of a river which continually swings from side to side. Mouth The mouth marks the end of a watercourse at a body of water, usually a lake or the sea.


Moraine is an accumulation of earth and stones carried by a glacier which is usually deposited into a high point like a ridge. The debris or rock fragments brought down with the movement of a glacier.

Nitrate (NO3)

Nitrate (NO3) is a chemical formed when nitrogen from ammonia (NH3), ammonium (NH4) and other nitrogen sources combine with oxygenated water. An important plant nutrient and type of inorganic fertilizer (most highly oxidized phase in the nitrogen cycle). In water, the major sources of nitrates are septic tanks, livestock feed lots and fertilizers. Nitrate (NO3) is a chemical formed when nitrogen from ammonia (NH3), ammonium (NH4) and other nitrogen sources combine with oxygenated water. An important plant nutrient and type of inorganic fertilizer (most highly oxidized phase in the nitrogen cycle). In rural water bodies, major sources of nitrates may include septic tanks, livestock wastes, and fertilizers.

Nitrite (NO2)

Nitrite (NO2) is a product in the first step of the two-step process of conversion of ammonium (NH4) to nitrate (NO3). Nitrite + Nitrate Nitrogen occurs naturally in rocks and groundwater. The forms of nitrogen found in water include nitrite (NO2) and nitrate (NO3-). The concentration of nitrogen in groundwater can be significantly increased by anthropogenic activities such as applications of excessive amounts of fertilizer and manure, and leaky septic systems. Nitrite is unstable in aerated water and is generally considered to be an indicator of pollution through improper disposal of sewage or organic waste. Nitrite (NO2) is a product in the first step of the two-step process of conversion of ammonium (NH4) to nitrate (NO3).

Non-point source pollution

Non-point source pollution occurs when precipitation runs off fields, streets or backyards. As this runoff moves across the land surface, it picks up soil particles and pollutants. A source of pollutants from a wide geographic area, such as stormwater runoff and stream bank erosion which can impair the quality of surface and groundwater sources of drinking water. Pollution of the water from numerous locations that are hard to identify as non-point source, like runoff over a parking lot or field, or atmospheric deposition.


Nutrients are materials such as fertilizer, manure, compost, sewage biosolids, and pulp and paper biosolids, that can be applied to land for the purpose of improving the growing of agricultural crops or for the purpose of a prescribed use. Nutrients are elements or chemicals (particularly phosphorus) that stimulate the growth of aquatic plants and may lead to eutrophication. A nutrient is something that nourishes and promotes growth. It is possible to have too many nutrients in an ecosystem, which can result in an unhealthy imbalance or overgrowth of certain species.


Outflow is the flow out of or through a waterpower facility, control structure, pond, reservoir or lake.


Outwash is sediments deposited by glacial meltwater creating stratified layers of gravel, sand and fines. The terms fluvial and outwash are used interchangeably. Outwash sand Outwash sand is sand drift, which becomes deposited by meltwater streams.


Overburden is unconsolidated geologic material above the bedrock. It is used to describe the soil and other material that lies above a specific geologic feature.


An oxbow is a crescent-shaped lake or slough formed in an abandoned stream bend that has become separate from the main stream by a change in its course.

Part per billion (ppb)

Part per billion (ppb) is a measure of the amount of dissolved matter in a solution in terms of a ratio between the number of parts of matter to a billion parts of total volume; equivalent to microgram per litre in water or one part per billion = one microgram per litre (µg /l).

Part per million (ppm)

Part per million (ppm) is a measure of the amount of dissolved matter in a solution in terms of a ratio between the number of parts of matter to a million parts of total volume; equivalent to milligram per litre in water or one part per million = one milligram per litre.


A pathogen is a bacterial or virus that is dangerous to human health. It can found in human or animal waste. Human pathogens can be found in septic tanks. Manure contains animal pathogens. A pathogen is an organism capable of producing disease. See also ‘E. coli.’


Preferential pathways are any structure of land alteration or condition resulting from a naturally occurring process or human activity which would increase the probability of a contaminant reaching water.


Percolation is the actual movement of subsurface water either horizontally or vertically; lateral movement of water in the soil subsurface toward a nearby surface drainage feature (e.g., stream) or vertical movement through the soil to the groundwater zone.


Permeable is a porous surface through which water passes quickly.


Permeability is the quality of having pores or openings that allow liquids to pass through. the property or capacity of a soil or rock for transmitting a fluid, usually water; the rate at which a fluid can move through a medium. The definition only considers the properties of the soil or rock, not the fluid. See also hydraulic conductivity.


Pesticides are chemicals including insecticides, fungicides, and herbicides that are used to kill living organisms. pH pH is a numerical measure of acidity, or hydrogen ion activity used to express acidity or alkalinity. Neutral value is pH 7.0, values below pH 7.0 are acid, and above pH 7.0 are alkaline.


Phosphorus is an essential nutrient that contributes to plant productivity and, in excessive amounts, pollutes and leads to eutrophication of a water system. Phosphorus accumulates along the entire length of a river from a variety of point and non-point sources.


A plume is a pattern of contaminant concentrations created by the movement of water. The spill/source site is the highest concentration, and the concentration decreases away from the source. See ‘contaminant plume’ and ‘pollution plume.’ A pollution plume is a pattern of contaminant concentrations created by the movement of water – an area of a stream or aquifer containing degraded water resulting from migration of a pollutant. Contaminants spread in the direction of the water movement. The spill/source site has the highest concentration, the concentration decreases as the plume moves away from the source.

Point source pollution

A source of contamination that originates in an identifiable location. Point-source pollution comes from a distinct source, such as an industrial discharge pipe, underground storage tank, septic system, or spills. An example of a source of pollutants would be a municipal treatment plant or an industrial facility, often by way of a pipe.


Porosity is the ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment.


Porous is having ‘pores’ or ‘holes’ – allowing liquid or gas to pass through. Potable water Potable water is water that is safe for drinking.


Precipitation is the deposits of water, in either liquid or solid form, which reach the Earth from the atmosphere. It includes rain, sleet, snow and hail. Precipitation is moisture falling from the atmosphere in the form of rain, snow, sleet or hail. Reforestation The planting of trees, saplings or seedlings on land that has been cleared of trees in the past.


Restoration is changing existing function and structure of wetland habitat so that it is similar to historical conditions.

Riffle/pool system

A riffle/pool system is a riverine system that alternates cycles of shallow broken water (riffle) and deeper still water (pool).

Riparian area

The riparian area is the area that lies as a transition zone between upland areas (such as fields) and other areas (such as streams, wetlands, lakes, rivers, etc.) The zone is intermittently inundated and usually supports wet meadow, marshy or swampy vegetation. Riverine Riverine is relating to or resembling a river.


Runoff is water that moves over land rather than being absorbed into the ground. Runoff is greatest after heavy rains or snowmelts, and can pick up and transport contaminants from landfills, farms, sewers, industrial or commercial operations or other sources.

Saturated soil

Saturated soil is soil that is full of moisture.


Sediment is material deposited by water, wind or glaciers. Fragmented organic or inorganic material derived from the weathering of soil, alluvial and rock materials. It is removed by erosion and transported by water, wind, ice and gravity.


The deposition of sediment from a state of suspension in water or air. 75th percentile The 75th percentile represents the value below which 75 per cent of the values occur. This value is used as opposed to a median value (50th percentile) to account for the tendency of Provincial Water Quality Monitoring Network samples to be collected during dry weather periods.


Sinkholes are circular or elliptical closed depressions in the surface, usually formed by the dissolution of underlying soluble bedrock, allowing surface water to enter the groundwater. Sinkholes can allow this contact to occur rapidly and do little to filter contaminants in the surface water. A sinkhole is a depression in the surface of the ground, with or without collapse of the surrounding soil or rock, which provides a means through which surface water can enter the ground and therefore come in contact with groundwater. Sinkholes often allow this contact to occur quite rapidly and do little to filter any contaminants the surface water may contain. A sinkhole is a depression in the surface of the ground, with or without collapse of the surrounding soil or rock, which provides a means through which surface water can enter the ground and therefore come in contact with groundwater.


Slope is ground that forms a natural or artificial incline.


Spawn is the mass of eggs deposited by fish, amphibians, mollusks, crustaceans and like animals. Spawn can be to produce and deposit eggs or sperm directly into the water, as fish do; to produce in large number. To spawn is to produce and deposit eggs in the reproductive process (particularly in aquatic animals).

Species at risk (SAR)

Species that are at risk of extinction, extirpation or endangerment globally or within a jurisdiction or region.


A spillway is the valley that results when glacial meltwater cuts into the landscape. Spillways are often composed of sand and gravel.

Standard deviation

A measure of how spread out the values in a data set are. If the data points are all close to the mean, then the standard deviation is close to zero. If many data points are far from the mean, then the standard deviation is far from zero.


Watershed stewardship is the responsible care of our natural resources and wildlife on a watershed basis. It is essential to balance human and economic needs against the needs of our natural environment. We all need a vibrant environment in order to ensure that we have plenty of clean water and a healthy ecosystem. As caretakers of our environment, we need to continue to develop and implement stewardship practices that protect and restore natural resources.


A stream is a body of water flowing on the surface of the Earth.


The discharge that occurs in a natural channel. Although the term ‘discharge’ can be applied to the flow of a canal, the word ‘streamflow’ uniquely describes the discharge in a surface stream course. The term ‘streamflow’ is more general than the term ‘run-off’, and may be applied to discharge whether or not it is affected by diversion or regulation.


Substrate is the base on which an organism lives. Stream substrate is the material that is at the bottom of the stream.


A subwatershed is an area that is drained by an individual tributary into the main watercourse of a watershed.

Surface water

Surface water is the water that is present on the surface of the Earth‚ and may occur as rivers, lakes, wetlands, ponds, etc. It is water on the earth’s surface exposed to the atmosphere (e.g., rivers, lakes, streams, ponds, reservoirs, etc.).

Surface Water Quality

Water quality relates to the chemical, physical, and biological content of water. The quality of surface water sources can be affected by nature patterns, geographic features, wildlife, and land uses.


Swamps are wooded wetlands with 25 per cent cover or more of trees or tall shrubs. Swamps are standing, to gently flowing, waters that occur seasonally or persist for long periods on the surface. Many swamps are characteristically flooded in spring, with dry relict pools apparent later in the season.


Terrestrial is living on or growing on land.


Till is a tough unstratified clay loaded with stones originating from finely ground rock particles that were deposited by glacial activity.


Topography is a detailed description or representation of the features, both natural and artificial, or an area. Also the physical and natural features of an area, and their structural relationships.

Total phosphorus

Total phosphorus refers to the total amount of phosphorus, in a sample. Phosphorus is an element that enhances plant growth and contributes to excess algae, low oxygen in streams and lakes. Total phosphorus is a nutrient that enhances plant growth and contributes to excess algae and low oxygen in streams.


A tributary is a stream or river that flows into another body of water. It is a stream that contributes its water to another stream or body of water. A tributary is a segment of a watercourse that joins with the main branch.

Unconfined aquifer

An unconfined aquifer is an aquifer for which the upper boundary is the water table. Unsaturated zone The subsurface zone above the water table in which pore spaces are only partially filled with water. Water in this zone is called soil moisture.


The expansion of the proportion of total population or area in urban areas.


A valley is a long, narrow depression on the Earth surface, usually with a fairly regular downward slope. A river or stream often flows through it.

Vulnerable area

Vulnerable areas under the Ontario Clean Water Act, 2006 are:

(a) A significant groundwater recharge area;

(b) A highly vulnerable aquifer;

(c) A surface water intake protection zone, or;

(d) A wellhead protection area.


The word vulnerability describes how easily a well or intake can become polluted with a dangerous material. Researchers have studied each municipal well and intake to determine how vulnerable they are.


A channel in which a flow of water occurs.


An area of land that drains into a river or lake.

A watershed is the area of land that contributes water to a lake, river, or stream. A watershed is an area of land that is drained by a river or a stream, and its tributaries, to a body of water such as a lake or ocean. It is often referred to as a drainage area, basin or catchment area for a watercourse. The area of land that drains water in a given region is known as a watershed. A watershed can be thought of as bathroom sink. Any rain or snow that falls within the sink-bowl runs down the sides of the sink and into the drain, which can also be thought of as a water supply intake such as a well or surface water intake pipe. Watersheds are based on natural boundaries, created by natural features of the land. They do not follow municipal, provincial or even national borders. Watershed is an area that is drained by a river and its tributaries. Watershed means the area of land that contributes water to a lake,

Watershed stewardship

Caring for our water, land, air and biodiversity on a watershed basis recognizing that everything is connected in a watershed and is affected by natural and human activities. See ‘Stewardship.’

Water Cycle

The process of water movement from the ground to the sky and back.

Water table

The water table is the surface below which the soil is saturated with water.


Any body of water flowing into another body of water.


A well is a hole in the Earth surface used to obtain water from an aquifer. For a bored well, an earth auger is used to bore a hole carry earth to the surface. The casing is usually steel, concrete or plastic pipe. Modern dug wells are dug by power equipment and typically are lined with concrete tile. Dug and bored wells have a large diameter and expose a large area to the aquifer. These wells are able to obtain water from less-permeable materials such as very fine sand, silt, or clay. Drilled wells are constructed by either percussion or rotary-drilling machines. Drilled wells that penetrate unconsolidated material require installation of casing and a screen to prevent inflow of sediment and collapse. A flowing, or Artesian, well is completed in a confined aquifer that has a water level higher than the ground surface at the location of the well. This causes water to flow out of the well.

Wellhead protection area

A wellhead protection area (WHPA) is an area that is related to a wellhead and within which it is desirable to regulate or monitor drinking water threats. A wellhead protection area (WHPA) is one of four main types of vulnerable areas identified in the Ontario Clean Water Act, 2006. A wellhead protection area means an area that is related to a wellhead and within which it is desirable to regulate or monitor drinking water threats. The surface and underground area surrounding a water well, or well field, that supplies a municipal residential system or other designated system through which contaminants are reasonably likely to move so as to eventually reach the water well or wells. Wellhead protection area means the surface and subsurface area surrounding a well that supplies a drinking water system, through which contaminants are reasonably likely to move so as to eventually reach the well. Wells draw water from underground areas called aquifers where water fills cracks in bedrock or spaces between grains of sand, gravel or dirt. Aquifers are replenished when water from rain and melting snow soaks into the ground. Sometimes, the water also carries pollutants. It can take years, or even decades, for water to reach a well. The speed depends on the characteristics of the soil and bedrock in the area.


A type of habitat that has water in it for all or part of the year.

A wetland is land seasonally or permanently flooded by shallow water as well as land where the water table is close to the surface; presence of abundant water causes poorly drained soils, favouring dominance of either water-loving or water-tolerant plants. Wetlands are often areas with high biodiversity and may help to filter pollutants from water and provide species habitat. Wetlands are lands such as a swamp, marsh, bog or fen (not including land that is being used for agricultural purposes and no longer exhibits wetland characteristics) that,

(a) Is seasonally or permanently covered by shallow water or has the water table close to or at the surface,

(b) Has hydric soils and vegetation dominated by hydrophytic or water-tolerant plants, and;

(c) Has been further identified, by the Ontario Ministry of Natural Resources or by any other person, according to evaluation procedures established by the Ministry of Natural Resources, as amended from time to time.

Wetland cover

The percentage of wetland cover is not part of the overall forest conditions grade. Wetland cover is the percentage of the watershed that is covered by wetlands which include swamps (treed and thicket), bogs, fens and marshes.

Wetland – Locally Significant Wetland (LSW)

A wetland which provides functions or exhibits characteristics that are pertinent to planning decisions, but has not been classified by the Ontario Ministry of Natural Resources.

Wetland – Provincially Significant Wetland (PSW)

A wetland that has been identified and classified as provincially significant by the Ontario Ministry of Natural Resources.


These tree plantings have reduced wind erosion and increased soil conservation.

List of Abbreviations and Acronyms

For local information purposes and subject to revision.

ABCA – Ausable Bayfield Conservation Authority

ABMV – Ausable Bayfield Maitland Valley Drinking Water Source Protection Region

ANSI – Area of Natural and Scientific Interest AO – Aesthetic objective

BMP – Best management practice

BOD – Biological oxygen demand

CA – Conservation authority

CLI – Canada Land Inventory

CO – Conservation Ontario

CWA – Clean Water Act, 2006

DFO – Department of Fisheries and Oceans Canada

DNAPL – Dense non-aqueous phase liquid

DWSP – Drinking water source protection

ECC – Environment and Climate Change Canada

GAWSER – Guelph All-Weather Sequential-Events Runoff Model

GIS – Geographic information systems

GPS – Global positioning systems

GUDI – Groundwater under the direct influence of surface water

GVA – Groundwater vulnerability analysis

HRU – Hydrological response unit

HVA – Highly vulnerable aquifer

ISI – Intrinsic susceptibility index

IPZ – Intake protection zone

LaMP – Lakewide Management Plans

MMAH – Ontario Ministry of Municipal Affairs and Housing

MNRF – Ontario Ministry of Natural Resources and Forestry

MECP – Ontario Ministry of the Environment, Conservation and Parks

MTO – Ontario Ministry of Transportation

ODWS – Ontario Drinking Water Standards

ODWSP – Ontario Drinking Water Stewardship Program

OMAFRA – Ontario Ministry of Agriculture, Food and Rural Affairs

MOHLTC – Ontario Ministry of Health and Long Term Care

OMNRF – Ontario Ministry of Natural Resources and Forestry

OMTO – Ontario Ministry of Transportation

OPG – Ontario Power Generation

PCB – Polychlorinated biphenyls

PGMN – Provincial Groundwater Monitoring Network

PPB – Parts per billion

PTTW – Permit to take water

PWQMN – Provincial Water Quality Monitoring Network

PWQO – Provincial water quality objective(s)

RAP – Remedial action plans

SGRA – Significant groundwater recharge area

SP – Source protection

SPA – Source protection area

SPA – Source protection authority

SPC – Source protection committee

SPP – Source protection plan

SPP – Source protection planning

SPR – Source protection region

STP – Sewage treatment plant

SWAT – Surface to well advection time

SWOOP – Southwestern Ontario ortho-photography

SWVA – Surface water vulnerability analysis

TDS – Total dissolved solids

TOT – Time of travel

WHPA – Wellhead protection area

WWIS – Water Well Information System

WWTP – Wastewater treatment plant 


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