Watershed Health Assessment and Monitoring

A massive undertaking, our Watershed Health Assessment and Monitoring project seeks to understand and evaluate the health of the Ottawa River watershed.

How do you know how healthy a river is?

This is a question Ottawa Rivekeeper is often asked. However, the answer, especially for a system as complex as the Ottawa River watershed, can be a challenging puzzle to untangle. There is great value in searching out an answer so that we can better understand what influences the health of the rivers in this watershed and help guide what needs to be done to protect it into the future.

Assessing the Health of the Ottawa River Watershed: Phase One

This is why Ottawa Riverkeeper is working on a Watershed Health Assessment and Monitoring project. This multi-year project builds off an initial study which brought together members of the Watershed Health Committee and insight from Algonquin communities from across the watershed. The initial study determined a series of indicators that will help answer the question of how healthy our rivers are. As we continue this investigation, we are partnering with Indigenous communities to co-design projects, working with communities throughout the watershed to understand local issues, and engaging citizen scientists to participate in community based monitoring projects. Through this effort to collect and analyse data, we hope to empower people as they learn more about the health of the watershed to take actions to protect the incredible Ottawa River.

Watershed Health Indicators:

Overview Web

Fourteen Watershed Health Indicators were identified as key metrics to understand the overall state of watershed. Each indicator influences some of those around it. We have presented this web of influence for you to explore and learn more about how we can measure the health of the watershed.

Click on an indicator to get a basic introduction to it, and follow the links to get a more in depth understanding of what it means as a measurement of watershed health and how it relates to the others.

Overview Web
Algal Blooms Water Temperature Dissolved Oxygen Chlorophyll-a Total Phosphorus Riparian Connectivity Combined Sewer Overflows Flow Change in Land Use Benthic Invertebrates Invasive Species Fish Richness Water Mercury Ice On/Off

Algal Blooms

Algae are a group of single-celled and multicellular plant-like organisms. Algal growth contributes and supports the ecosystem in much the same way that plants do, through the production of oxygen and as a potential food source for smaller animals. However, when environmental conditions shift from their normal ranges, this can promote algal blooms, a rapid increase in population size of algae.

Find out more!

Water Temperature

With global temperatures on the rise, water temperature (particularly annual maximum temperatures) will be a crucially important indicator of watershed health moving forward. Water temperature is strongly correlated with a number of other important indicators of ecological status, and can often help to explain, give context to, or even predict changes in habitat quality.

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Dissolved Oxygen

Dissolved oxygen (DO) is the concentration of free oxygen in the water column and comes from aquatic plants and algae through photosynthesis, and can also be transferred from the air at the surface of the water. DO is essential for all aquatic life and for the decomposition of organic waste. The amount of available oxygen in the water column is also affected by several abiotic factors including temperature, salinity, pressure and depth, wind, flow, and wave action.

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Chlorophyll-a is used in oxygenic photosynthesis and is the predominant form of chlorophyll in green plants and algae. Measuring the presence of chlorophyll-a in an aquatic environment allows for a better understanding of the density and prevalence of algae which can have an impact on the concentration of dissolved oxygen or likeliness of algal blooms.

More information coming soon!

Total Phosphorus

Phosphorus is a fundamental building block of life. It has key structural roles in genetic material (eg. DNA) and cellular membranes, and is an active component of cellular energy production, storage, and transfer, meaning many necessary biochemical processes that all living organisms rely on (such as respiration, and nutrient absorption) can only happen if phosphorus is available.

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Riparian Connectivity

Natural, vegetated riparian areas, the unique, transitional space between aquatic and terrestrial ecosystems, provide numerous benefits including nearshore habitat, filtering runoff, moderating local temperatures, and stabilizing shorelines. Measuring riparian connectivity can provide important information on the health of a watershed and a better understanding of the resilience to threats these areas have compared to shorelines that have been developed.

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Combined Sewer Overflows

Everytime there is a Combined Sewer Overflow, sewage, along with stormwater is released into a waterbody introducing pollutants, pathogens and excess organic waste. Untreated or inadequately treated sewage poses health risks for people who use the water for recreational activities, such as swimming, paddling, etc. It also impacts aquatic ecosystems as the presence of organic matter, and its decomposition, decreases the amount of dissolved oxygen available.

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How much water or volume of water present at a given time and how quickly it moves along the length of the river determines flow. Flow can provide context to a number of other indicators and as an important measure to factor when examining water chemistry or understanding impact of pollutants (for example, the same concentration of pollution will impact a river with low flow differently than one with high flow). Comparing flow within the same reach can help identify different trends and, when affected by barriers, can impact aquatic biota.

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Change in Land Use

Land use is a classification for all the various ways an area of land be used and includes agriculture, urban, roads, natural and harvested forests, wetlands and protected areas. Changes in land use have implications for both the quantity and quality of water introduced to the river through runoff and can help analyse changes in other indicators in proximity to where land use changes have occurred.

More information coming soon!

Benthic Invertebrates

Benthic invertebrates are the organisms found in soils, rocks and organic materials that make up stream, river, and lake beds. Pollution tolerance varies greatly between different species, so the relative abundances of pollution-sensitive and pollution-tolerant benthic invertebrate species is a good indicator of water quality and ecosystem health.

More information coming soon!

Invasive Species

Invasive species are non-native species that have been introduced to a habitat and are able to outcompete native species. Invasive species disrupt the established ecosystem which can result in a decrease in habitat quality and health.

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Fish Richness

Fish richness is a measure of how many different species of fish are present in an ecosystem or habitat. Generally speaking, higher species richness is better, but some confounding factors include habitat type and the presence of invasive species (which can increase richness while threatening ecosystem health).

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Water Mercury

Mercury is highly toxic, but naturally occurring concentrations of it are bound by plants and sediment and removed from the water column. However, human activity introduces excess mercury, resulting in free mercury in the water column. Water mercury is therefore a useful indication of human impact on the watershed.

More information coming soon!

Ice On/Off

Ice on is the date when a body of water is fully covered by ice, and ice off is the date when the ice disappears from the water surface. These measurements provide information about several environmental conditions, such as air temperature, water temperature, and flow.

Find out more!

Open Data:

Explore data by the 14 ecological indicators that contribute to the Watershed Health Assessment and Monitoring initiative.

Our open data portal has been created to allow everyone access to a diverse range of information about the Ottawa River watershed. It is a platform designed to facilitate the exploration and discovery of the many reports and data available about the Ottawa River and its tributaries from a wide variety of sources.

The portal remains a work in progress, and will continue to be improved and expanded over time.

Partnerships with Indigenous Communities:

One of the key pillars of the Watershed Health Assessment and Monitoring project is partnerships with Indigenous communities in the watershed. This involves developing co-designed projects with two Algonquin Communities; Kitigan Zibi Anishinabeg and Kebaowek First Nation.

More details on these projects and partnerships are coming soon!

Community Based Monitoring:

Road Salt Monitoring

This initiative will see a team of volunteers take regular measurements of conductivity at several sites. We can then track the impact of road salt on the waterways over the winter.

Algal Bloom Monitoring

While algal blooms can be common in the Ottawa River watershed, we still can’t predict them. It is therefore very important for us to monitor algal blooms, and the wider community is vital in that effort.

Ice On/Off Observations

We keep track of observations of Ice On and Ice Off throughout the watershed from the Riverwatch network and the general public. These observations help us track seasonal changes over time.

Land Use Monitoring

As a part of the Watershed Health Assessment and Monitoring project, Ottawa Riverkeeper is collecting data about land use, and we need your help!


RBC Foundation
Environment and Climate Change Canada
ECHO Foundation