About the Categories

About the Watershed Report Card Resource Categories

  • Surface Water Quality - Surface water is the water that makes up our rivers, lakes and streams. Conservation Authorities assess the quality of these water bodies by measuring water chemistry (phosphorus, oxygen) and organisms that live in the sediment at the bottom of streams and rivers. Some Conservation Authorities also measure bacteria.
  • Forest Conditions - Forests provide habitat and shade; they help to clean our air and water and they protect the soil which promotes water infiltration and reduces both erosion and flooding. Forests also help to cool the land and air - nature’s air conditioner! Conservation Authorities assess the area of their watersheds covered by forest; and the amount of forest "interior" (areas that are more han 100 meters from the forest edge which provides crittical habitat for many species including songbirds.
  • Groundwater Quality - Groundwater is the water found beneath the earth’s surface, in water bearing layers known as aquifers. Groundwater is difficult if no impossible to clean once contaminated, so it is critical to protect areas of groundwater rechare. Conservation Authorities monitor water chemistry (nutrients, metals, chlorides and nitrates).
  • Impervious Land Cover - Impervious land cover includes all surfaces across the landscape that do not allow for the infiltration of rain and water into the soil surfaces. This includes a variety of surfaces from roads, driveways, sidewalks, parking lots and rooftops to heavily compacted soils associated with urban and residential development.

Reporting on Surface Water Quality

The three surface water quality indicators reflect key issues related to surface water quality across the province: nutrients (Total Phosphorus), bacteria/waste (E. coli), and aquatic health (Benthic Macroinvertebrates). The Ontario Ministry of the Environment points out that "Monitoring stream-water quality can help us understand the impacts of land-use activities on water quality, enabling us to make informed decisions about managing and protecting our water resources."

Total Phosphorus - Phosphorus is a chemical that occurs both naturally and as a result of our activities. It is typically used in fertilizers and is found in municipal waste and from other human sources. It promotes plant growth which is good for agricultural yields, yet high concentrations can be harmful on the environment causing algae blooms which can reduce the okygen available to plants and fish.

Wetlands and forests help to filter phosphorus, reducing its impac on lakes and rivers. Without these riparian zones, however, phosphorus can run off easily contaminating both surface and groundwater sources. 

Phosphorus can also impact human health indirectly by contaminating drinking water sources. 

The Provincial Water Quality Monitoring Network (PWQMN) is the main source of total phosphorus data for many Conservation Authorities. Other Conservation monitoring programs or monitoring by partner agencies may provide data for some watersheds. 

E.coli (Escherichia coli) - E.coli is a species of bacteria that is broadly accepted as the key indicator of fecal contamination in surface water sources. The main sources of E.coli are municipal sewage discharges, or runoff from failing septic systems, or agricultural operations. E.coli is often more present after significant rainfalls or snow melts and because it travels rapidly down creeks, rivers and streams to lakes and popular beaches. 

E.coli can impact human health if it gets into drinking water sources. It can cause severe illness including diarrhoea, cramps and possibly fever. Young children, the elderly, and chronically ill are at particular risk.

Currently, there is no province-wide program whereby Conservation Authorities collect water samples for E.coli. However, many Conservation Authorities take surface water samples, some through monitoring programs in conjunction with partner agences, such as Public Health Agencies.

Conservation Authorities indicate in their watershed report cards whether or not they monitor and report on E.coli. Conservation Halton’s Watershed Report Card does not include E.coli in its scores. Some Conservation Authorities are involved in beach monitoring and reporting for E.coli in partnership with local public health units.

Benthic Macroinvertebrates - To help determine the quality of water in streams, Conservation Authorities collect small organisms (Benthic Invertebrates) from the stream’s sediment. These small bugs act as barometers of water quality. Some can tolerate pollution while others disappear as pollution increases. Currently, most Conservation Authorities have a benthic monitoring program and a number are planning to start. The current Watershed Report Card guidelines adopt the Hilsenhoff 1988 Family Biotic Index as modified by New York State (Smith et al 2009).

Surface Water Quality Monitoring Sites

The Conservation Authorities strive to have a surface water quality monitoring site for each subwatershed that represents the quality of the water at the outlet. If there is more than one site, information from the site closest to the outlet is generally used for indicator reporting. 

Reporting on Forest Conditions

Three indicators are used by Conservation Authorities to assess forest conditions at the watershed and subwatershed scale: Percent Forest Cover, Percent Forest Interior, and Percent Riparian Zone Forested. Conservation Authorities use the most recent data available to them to calculate forest conditions.

Forest Cover - Most Conservation Authorities use Southern Ontario Land Resources Information System (SOLRIS) I or II mapping data as he primary source of forest cover. As well, forested or wooded area can easily be measured using GIS (Geographic Information System) technology. Depending on resources, some Conservation Authorities will have newer or improved mapping.

In the watershed report cards, the words ’forest’ and ’woodland’ are use interchangeably. Because the Conservation Authorities use GIS, the SOLRIS definition for woodland is used, with ’woodland’ describing areas with more than 60% tree cover and greater than 2 metres in height. This aligns with the Ecological Land Classification for Southern Ontario (Ontario Ministry of Natural Resources 1998).

Forest Interior - Forest Interior refers to the protected core area found inside a woodlot that some bird species require to nest and breed successfully. The outer 100 metres perimeter of a woodlot is considered ’edge’ habitat and prone to high predation, sun, and wind damage, and is more susceptible to invasive species. For these report cards, forest interior is that portion of a woodlot that remains when a 100 metre buffer is removed from the inside perimeter of a wood lot (e.g. 100m from the outside edge).

Riparian Zone Forested - The watershed report cards track and measure the riparian zone (or buffer zone of vegetation) which is a swath of land, 30 metres wide, on both sides of a river or stream. These vegetation zones are important areas because they have many functions; they provide important habitat for birds, fish and other wildlife and organisms, it helps to improve water quality by filtering sediment and contaminants, and it is essential in helping to reduce or prevent flooding and erosion. 

Reporting on Groundwater Quality

Conservation Authorities rely on the Ontario Drinking Water Quality Standard for Nitrite + Nitrate and for measuring and reporting on chloride concentrations. They collect the majority of data within the Provincial Groundwater Monitoring Network. 

Two indicators are used to assess groundwater quality for the Conservation Authority Watershed Report Cards:

  • Nitrite + Nitrate - Although nitrogen occurs naturally in rocks and groundwater, the concentration of nitrogen can be significantly increased by the overuse of fertilizer, spilled manure, and leaky septic systems. Conservation Authorities rely on the Provincial Groundwater Monitoring Network as one source for nitrite + nitrate data.
  • Chloride - Chloride is a naturally occurring element that can be found in concentrations that exceed drinking water quality standards under natural circumstances, sometimes due to the type of rock the groundwater is coming from. It can be difficult to determine whether high chloride levels are due to natural or human causes.

About Groundwater

The Ontario Ministry of Natural Resources states that Groundwater is an important source of drinking for approximately 3 million people living in Ontario. Groundwater is water that seeps into the ground from precipitation and is stored below the surface of the earth in aquifers which are areas of tightly layered sand, gravel and rock.

Groundwater is naturally replenished by surface water from precipitation, streams, and rivers when the water seeping into the ground reaches the water table. Groundwater eventually flows to the surface (discharges) naturally at springs and streams and can form wetlands.

Threats to Groundwater

Groundwater sources can be threatened by activities such as:

  • leaky fuel or chemical storage containers,
  • road salt spreading,
  • spreading of sewage treatment sludge,
  • spilled fertilizers or chemicals such as dry cleaning solvents,
  • accidental spills, 
  • septic systems,
  • underground sewers,
  • landfills,
  • manure, 
  • or even from overuse.

Underground aquifers are recharged mainly by rainfall and snow. As long as the water contained in these aquifers is not extracted faster than it is replenished, groundwater is a renewable resource.

What is an Aquifer and Recharge Area?

An aquifer is an area of soil or rock under the ground that has many cracks and spaces and has the ability to store water. Water that seeps into an aquifer is called recharge. Much of the natural recharge of an aquifer comes from rain and melting snow. Aquifers can be particularly vulnerable to contamination. If contaminated, it can be very difficult and expensive - even impossible - to clean up or restore.

The land area where the land or snow seeps down into an aquifer is called a recharge area. Recharge areas often have loose soil such as sand or gravel which allows water to seep slowly into the ground. Areas with shallow fractured bedrock are also often recharge areas.

A recharge area is considered significant when it helps maintain the water level in an aquifer that supplies a community with drinking water. Under the Clean Water Actt 2006, it may also be considered significant if it plays a necessary role in recharging cold water streams that support specific fish.

Impervious Land Cover

Stormwater poses a significant threat to surface water quality. After a big rainstorm or snowmelt, pollutants from a variety of activities on the land such as parking lots, construction zones, and lawns can travel very quickly as runoff to water courses such as creeks, rivers, and streams, and from there, into lakes or other bodies of water. Under natural conditions, stormwater is absorbed into the ground or filtered by plants and trees. 

In urbanized areas, however, the water runs rapidly into storm drains, municipal sewers and drainage ditches into streams, rivers, and lakes, and along the way, it picks up pesticides, road salts, heavy metals, oils, bacteria, and other harmful pollutants. 

Stormwater can cause increased flooding, riverbank erosion, murky water, degraded fish and animal habitat, changes in stream flow, infrastructure damage, and contaminated water bodies. 

Conservation Authorities promotte smart environmental practices such as low impact development (LID) or green infrastructure activities to manage or prevent stormwater runoff impacts.

Watersheds should maintain less than 10% impervious cover to maintain abundance and biodiversity of aquatic species. Significant impairment occurs above that level and watersheds are severely degraded at the 25% to 30% level.