Protecting Ottawa's waterways

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Water Environment Strategy

The Water Environment Strategy (WES) helps protect the health of the City’s waterways, wetlands and groundwater and reduces the impacts of human activity. It is one of 17 projects approved under the Ottawa River Action Plan.

More than 4,500 km of waterways span the Mississippi, Rideau and South Nation watersheds, including hundreds of small streams, municipal drains, and major creeks and rivers such as the Carp, Jock, Castor and Bear Brook. These ultimately drain to the Ottawa River. A healthy water environment provides safe, abundant drinking water; supports agriculture, recreation and tourism; lessens the impact of flood events; and helps sustains fish and wildlife.

The Water Environment Strategy was brought forward in two phases:

  • The Phase 1 WES report was approved by Council in March 2014 and contains a summary of key issues, jurisdictions and roles as well as a work plan
  • The Phase 2 WES report and supporting document establishes 20-year goals and objectives, and sets priorities for 2016-2018. It was approved by Council in June 2016.

The strategy was developed in consultation with several City departments, the Mississippi Valley, Rideau Valley and South Nation Conservation Authorities, external agencies and stakeholders, and residents. A public Water Round Table was held in 2014 to gather input and ideas early in the process.

The strategy will be implemented through four-year action plans to be tabled with Council once per term along with a progress report that addresses accomplishments, challenges and gaps. The 2016-2018 work plan is included as Appendix 1 in the Water Environment Strategy Phase 2 Report.

Have a question or comment on the Water Environment Strategy?

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Stream Setbacks

Ensuring that development is set back an appropriate distance from watercourses helps ensure a healthy, natural riparian zone and provide a margin of safety from hazards associated with flooding and unstable slopes.

If your property backs onto a creek or ravine, preserve the health of the creek by retaining or planting trees and bushes along the top of the bank. Be sure to use native species.

The benefits:

  • Stream setbacks reduce property damage and downstream flooding when streams overflow onto their natural floodplains.
  • Vegetation within stream setbacks filters and traps pollutants, and helps to maintain water quality.
  • Vegetated stream setbacks protect against erosion by slowing runoff and stabilizing stream banks.
  • Stream setbacks with natural vegetation provide habitats for fish and wildlife. Vegetated stream setbacks provide cover for fish and wildlife and keep the water cool by providing shade.
  • Stream setbacks increase property values and provide economic benefits by reducing the need to combat flooding, repair eroding stream banks, and replace damaged property.

For more information about responsible stewardship of shorelines and other natural features, contact the Landowner Resource Centre :

Rideau Valley Conservation Authority
3889 Rideau Valley Dr., Manotick, ON K4M 1A5
Phone: 613- 692-3571 ext. 1128 or 1132

Water Environment Protection

The City's Surface Water Quality program works in partnership with environmental and community groups. Together, they coordinate a variety of social marketing campaigns, environmental projects and educational materials that inform Ottawa residents about healthy habits they can adopt to protect and preserve our water environment.

Our everyday lives have an impact on the Ottawa and Rideau Rivers and their tributaries. For example, when rain falls or snow melts, dirt, debris, oil, antifreeze, detergents, pesticides, pet excrement, and all kinds of other pollutants get washed from driveways, parking lots and streets into storm drains. This polluted water is immediately transported to nearby streams and rivers.

The Water Environment Protection Program assesses the state of surface waters in the City of Ottawa and coordinates initiatives to preserve and improve the aquatic environment. Six rivers, four lakes and 40 creeks are regularly monitored to determine the current state of water quality and to assess changes over time. As sources of pollution are identified, City staff initiate corrective action and coordinate action plans with conservation authorities and provincial and federal agencies. Monitoring data is also used to develop strategies to address water quality problems and to evaluate their success.

Surface Water Protection in Ottawa

To learn more about the Water Environment Protection Program, contact

Water Quality in Ottawa's rivers, lakes, and streams

Summary of Surface Water Monitoring Results in Ottawa

Major Rivers

Water quality in the Ottawa, Mississippi and Rideau Rivers is generally good to excellent. This is largely due to the relatively low proportion of urban development and agriculture upstream of Ottawa.

The exception to the overall “good to excellent” assessment of the City’s major rivers are the two sites located in the most downstream stretch of the Rideau River (at the Bank Street Bridge and St. Patrick Street Bridge), which are rated fair.

Levels of phosphorus in the Rideau River are generally much higher than in the Ottawa and Mississippi Rivers.

Major Tributaries

Water quality in the City’s major tributaries varies. The Jock River has a water quality index ranging from fair to good depending on the location; the Castor is rated marginal to fair; the Carp is poor to fair; and Bear Brook is marginal. Levels of metals in the streams are generally good to excellent; E. coli levels are fair to good in the Jock River, poor to fair in the Carp, and poor to marginal in the other major tributaries. Phosphorus levels are poor to marginal in the Jock River and mostly poor for the other three major tributaries.

Smaller Tributaries

Water quality in the City’s smaller tributaries varies from poor to excellent depending on the pollutant. Levels of metals are good to excellent in the majority of areas, with marginal to fair ratings observed in more urbanized settings. For the most part, phosphorus and E. coli levels are rated as poor to fair in both rural and urban creeks, with good to excellent ratings observed in areas upstream of the City.

In terms of meeting water quality targets, urban creeks are worse than rural creeks. Higher levels of metals in urban creeks reflect urban runoff from roads and parking lots.

Areas of Concern

Six creeks were identified during the trends analysis as areas of concern: Bilberry Creek, Green Creek, Bear Brook, Beckett’s Creek, Cardinal Creek and Casey Creek. These monitoring stations show high levels of phosphorus, E. coli and metals. Some of these tributaries drain urban areas, some drain rural areas, and some drain areas with mixed land use.

Surface Water Quality Trends

With the exception of the main channels of the Ottawa and Mississippi Rivers, and naturalized areas upstream of the urban area, phosphorus is a concern in all of the City’s rivers and streams. In all watercourses other than these exceptions, phosphorus levels are rated mostly as poor or marginal and average concentrations exceed water quality targets.

E. coli is not a concern in the Ottawa and Mississippi Rivers. Increasing levels of E. coli are seen in the Rideau River with distance downstream. However, differing levels suggest the influence of local sources rather than a cumulative effect. A significant increase in phosphorus levels is noted when the river reaches the Black Rapids. This is likely the influence of some rural tributaries which empty into the Rideau upstream from Black Rapids.

Increasing levels of phosphorus and E. coli have been found in the Ottawa River, downstream of the urban area. This is due to the influence of the Rideau and Gatineau Rivers, stormwater run off from the Gatineau and Ottawa urban area, and the wastewater treatment plants that serve Ottawa and Gatineau. Increased levels of pollutants are seen in Ottawa’s tributaries during the spring melt when runoff picks up pollutants from farms, yards, roads and parking lots.

Overall, water quality tends to improve as the size of the watercourse increases. Patterns in water quality in the rural and urban areas are somewhat inconsistent, with locations of high water quality found in both rural and urban areas and vice versa. However, there is some evidence that rural tributaries flowing through natural areas (forests or wetlands) are of higher quality than those flowing through agricultural and urban areas.

In addition, water quality index values have generally been better when comparing the index values from the last five years against earlier results, suggesting that water quality may be improving across most water courses within Ottawa.

City of Ottawa Baseline Water Quality Monitoring Program

Why do we monitor?

Water quality monitoring is important and helps answer questions about the condition of a body of water (i.e., the levels of pollutants), stresses on water and the effectiveness of our protection, mitigation and restoration programs. The data collected at program monitoring locations sheds light on trends and is used as baseline information to measure the condition of other water bodies. 

Understanding the health of our rivers and streams is vital to protect the natural environment. Water quality data and information collected by WEP is used by internal City departments for investigations, planning, and restoration and remediation efforts. It is also used by external agencies such as the Ministry of Natural Resources and Forestry (MNRF), the Department of Fisheries and Oceans (DFO) and the three Conservation Authorities in Ottawa.

Through monitoring we can identify water quality problems, and then develop strategies to address them. Ongoing monitoring allows us to see if our efforts have been successful, and then adjust or adapt activities, if necessary, to achieve our objectives.

How do we evaluate water quality data?

Water quality data is evaluated against three sets of criteria – the Provincial Water Quality Objectives (PWQO), the Canadian Water Quality Guidelines (CWQG) for the Protection of Aquatic Life, and the Canadian Council of Ministers of the Environment (CCME) Water Quality Index. The provincial objectives and federal guidelines protect all forms of aquatic life and recreational uses. The CCME Water Quality Index translates complex water quality data into simple terms (e.g., excellent, good, poor) for reporting.

Similar to the Provincial Air Quality Index, the Water Quality Index gives information on overall water quality. The end result is a single index score between 0 and 100 that describes the overall water quality.

Index values closer to 100 indicate higher water quality, while values closer to zero indicate poorer water quality. For an explanation of what a specific Water Quality Index score means, see the table below.

The following water quality categories are recommended by CCME (2001):

Calculated WQI Category What it means
95?100 Excellent Water quality is protected and is virtually threat or impairment free; conditions very close to natural or pristine levels. These index values can only be obtained if all measurements are within objectives virtually all of the time.
80?94 Good Water quality is protected with only a minor degree of threat or impairment; conditions rarely depart from natural or desirable levels.
65?79 Fair Water quality is usually protected but occasionally threatened or impaired; conditions sometimes depart from natural or desirable levels.
45?64 Marginal Water quality is frequently threatened or impaired; conditions often depart from natural or desirable levels.
0?44 Poor Water quality is almost always threatened or impaired; conditions usually depart from natural or desirable levels.

How and what do we monitor?

The City’s Baseline Monitoring Program monitors water quality across Ottawa and identifies long term trends. Six rivers, four lakes, and forty creeks are monitored on a monthly basis unless prevented by site conditions (such as ice cover). Each sample is analysed for 50 different parameters:

Field Parameters

These parameters are measured using hand held equipment while at the monitoring site:

  • Conductivity
  • Dissolved Oxygen
  • Temperature
  • Turbidity
  • pH

Laboratory Parameters

Samples are collected and transported to a laboratory for analysis on the following parameters:

General Chemistry

  • Alkalinity
  • Calcium
  • Chloride
  • Dissolved Organic Carbon
  • Hardness
  • Potassium
  • Silicon
  • Sodium
  • Sulphate
  • Total Suspended Solids


  • Ammonia
  • Nitrate
  • Nitrite
  • Total Kjeldahl Nitrogen
  • Phosphorous, total
  • Phosphorous, reactive


  • Aluminum
  • Antimony
  • Arsenic
  • Barium
  • Beryllium
  • Bismuth
  • Boron
  • Cadmium
  • Chromium
  • Cobalt
  • Copper
  • Iron
  • Lead
  • Magnesium
  • Manganese
  • Molybdenum
  • Nickel
  • Selenium
  • Silver
  • Strontium
  • Thallium
  • Tin
  • Titanium
  • Tungsten
  • Uranium
  • Vanadium
  • Zinc
  • Zirconium


  • E. coli

Where can I find Ottawa’s baseline water quality data?

For an overview of the water quality of Ottawa’s rivers, lakes and streams please see our Interactive Water Quality Map. For specific monitoring results from 1998-2014, please visit the Water Quality – Baseline Surface Water Monitoring Program data set found on the City of Ottawa’s Open Data archive.

Water Quality in Ottawa’s Rivers, Lakes, and Streams

Interactive Water Quality Map

The summaries for more than 130 monitoring stations are mapped on the interactive water quality map below. This information reflects conditions in 2014 and has been provided by the City of Ottawa’s Baseline Surface Water Monitoring Program. Monitoring results obtained between 1998 and 2014 can be viewed by accessing the Water Quality – Baseline Surface Water Monitoring Program data set found on the City of Ottawa’s Open Data archive. For an explanation of what each Water Quality Index rating means, please see How do we evaluate water quality data?

Staff gauges

Staff gauges provide a quick and inexpensive way to record water levels during high water conditions. They are similar to vertical measuring tapes that are typically seen in or near watercourses such as streams and rivers.

The City, in cooperation with local conservation authorities, also uses information obtained with the staff gauges to update flood plain mapping and to improve the City’s response to flooding.

Local conservation authorities and the Ottawa River Regulation Planning Board monitor and forecast freshet conditions along the Ottawa, Rideau, Mississippi and South Nations River watersheds. The City’s additional staff gauges build on the existing monitoring network throughout these watersheds.


Rideau River

  • Osborne Street (east of Brewer Park)
  • Rideau River Drive South at Fentiman (east of Windsor Park)
  • Brantwood Park (along Onslow Crescent)
  • New Edinburgh (near southeast side of Union Street Bridge)

Ottawa River

  • Morehead Drive (Willola Beach)
  • Buckham's Bay (Ritchie Avenue Boat Launch)
  • Armitage Avenue (Armitage Avenue / Greenland Road)
  • Britannia Village (Jamieson Street)
  • Cumberland (Morin Road, Leo Lane / East Shore)