Priority Tributary Nutrient and Water Quality Monitoring

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Water quality monitoring data is collected in priority tributaries as part of binational efforts under Aneex 4 of the Great Lakes Water Quality Agreement (GLWQA) to estimate nutrient loading to the waters of the Great Lakes. At present, the focus is primarily tributaries of Lake Erie, the smallest, shallowest of the Great Lakes, and most susceptible to algal blooms. Tributaries may be added or removed from active monitoring dependent upon recommendation of binational working groups under the GLWQA. These data are used to track and report on progress towards meeting nutrient loading targets established for Lake Erie. The data also contribute to our understanding of the factors that affect tributary and nearshore and offshore water quality, algae growth and overall ecosystem health.

Version 11.0.0
Data Steward Email
Data Collection Organization Environment and Climate Change Canada (ECCC) / Environnement et Changement climatique Canada (ECCC)
Data Upload Organization Environment and Climate Change Canada (ECCC) / Environnement et Changement climatique Canada (ECCC)
Progress Code onGoing
Maintenance Frequency Code asNeeded
Data source URL
Topic Category Code inlandWaters
Keywords Water quality, Tributaries, Lake Erie, Lake Ontario, Nutrients, Major Ions, Loadings
Spatial Extent -83.177° 42.079°, -79.157° 43.814° (W S, E N)
Temporal Extent 2011-11-14 to 2023-08-08
Date Published
Alternate Formats FGP-HNAP ISO:19115-2 (XML) , W3C DCAT (XML) , W3C DCAT (JSON-LD)


Environment and Climate Change Canada (ECCC) / Environnement et Changement climatique Canada (ECCC). 2023-11-06. "Priority Tributary Nutrient and Water Quality Monitoring" (dataset). 11.0.0. DataStream.

Funding Sources

Government of Canada

Data Collection Information

Sample collection for tributary nutrient load monitoring and assessment is conducted year round in several priority watersheds in the Lake Erie basin. At each monitoring station, water samples are collected by an automated sampler, which is located within a fixed installation at, or near, a Water Survey of Canada (WSC) hydrometric station. Water samples are collected on a minimum bi-weekly frequency. In addition, water samples are taken during wet weather induced flow events, identified from WSC hydrographs, over the two-week period to best capture the full variation of stream flows at each station. Samples are drawn directly from submerged polyethylene intake lines via submersible pumps, then collected into pre-cleaned polyethylene bags and are refrigerated at all times. Samples are analyzed for nutrients and major ions by the National Laboratory for Environmental Testing (NLET) and follow all accredited QA/QC laboratory procedures.

Data Collection Processing

As part of quality assurance procedures, replicate grab samples are collected on each visit to retrieve samples from the automated samplers. Validated sample data for tributary nutrient load monitoring are held in one of ECCC’s national water quality databases (NAQUA) and each data point is QC flagged according to ECCC data qualifying procedure. Values reported below the detection limit (i.e., trace values) and samples below the detection limit (i.e. left censored values) are denoted with a “T” flag and “L” flag respectively.

Open Government Licence (OGL)

See disclaimer for details.

Data Disclaimer

Environment and Climate Change Canada employs every reasonable effort whenever feasible, to ensure the currency, accuracy and precision of the information provided. However, there are some limitations due to the sources of the data and the technology used in its processing and management. Furthermore, the material or any data derived using the data is subject to interpretation. Users are responsible for verifying that the supplied material is appropriate for the use or application for which they wish to employ it. The water quality and aquatic ecosystem data released may include provisional and/or validated data. Provisional data should be considered with greater caution as it has yet to be validated with quality control and quality assurance activities, which may result in significant change made to the data. Environment and Climate Change Canada makes no representation or warranty of any kind, either expressed or implied, as to the information presented, nor as to its fitness for any particular use. Environment and Climate Change Canada does not assume nor accept any liability arising from any use of the information and applications used to display or use the information. The data are not intended for any legal, or navigation purposes. The data may change from time to time as updated information is received. If any information seems to be incorrect, raises concerns, or for more information on this data, please communicate with the Environment and Climate Change Canada contact provided within the application. The material might contain links to third party sites. Environment and Climate Change Canada provides these links only as a service and convenience. Environment and Climate Change Canada takes no responsibility for the content at third party sites and in no way implies an endorsement or recommendation of the products, services or information found there. A third party site may have a privacy policy different from that of Environment and Climate Change Canada. Environment and Climate Change Canada does not assume nor accept any liability arising from any use of third party sourced content.

API Access

curl -G --data-urlencode "\\$filter=DOI eq '10.25976/qh88-c242'" -H "x-api-key: PRIVATE-API-KEY"



Updated with new measurements

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Added new observations

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Updated with new observations

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Dataset updated

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September 2022 dataset update

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Updated the dataset to include the most recent data

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Latitude/Longitude values truncated in original file

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Dataset updated with the most current data available

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Updated parameter mapping

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Our export was truncating coordinates to 2 decimals. Re-exported and updated

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initial submission

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