Hydrometric Program (Streamflow and Water Level Monitoring)

WRMD Near Real-Time Access
WSC Historical Data Access
Stage and Streamflow
Ice Conditions
Reports and Publications
Disclaimer
Contact Info

 

The province of Newfoundland and Labrador operates a province-wide network of hydrometric stations that provide near real-time water level and streamflow data. Since 1975, this work has been supported through a co-operative cost-shared agreement for water quantity surveys. This federal-provincial agreement provides a mechanism to harmonize hydrometric data collection, processing, and distribution in a consistent and coordinated way. Furthermore, it has allowed two levels of government to work cooperatively in the area of water quantity surveys. The standardized data collected through this network is used to facilitate resource planning and management in general, and the design and implementation of project related to navigation, hydro-electric development, irrigation, drainage, flood control, recreation, domestic and industrial water supply, and other purposes.

A total of 103 stations (as of 2025-26) are currently operated under the agreement. Of these 103 stations, 16 are designated as federal, 32 as federal-provincial and 55 as provincial. 74 of these stations provide coverage for the Island and the remaining 29 for Labrador. About half (45%) of the stations in the province are industry funded, where mining, hydro and aquaculture companies are the main industry partners.

The province is also in the process of establishing and growing its own provincial water level monitoring network. The network currently includes 20 stations, most of which have been installed in recent years. The majority of these stations are located at mining and industrial sites and are installed together with real-time water quality (RTWQ) monitoring instrumentation.

In the province, near real-time data is collected from remote locations via the Geostationary Environmental Satellite (GOES) system, owned by the United States governments National Oceanic and Atmospheric Administration (NOAA) and operated by the National Environmental Satellite, Data, and Information Service (NESDIS). The Department of Environment, Conservation and Climate Change developed and maintains a software (ADRS – Automatic Data Retrieval System) to access real time data. ADRS is used to automatically collect, process, and distribute near real-time data.

At each hydrometric station, instruments are programmed to measure water level every five minutes, where measurements are logged and stored on an on-site digital data logger. The data is then automatically transmitted to a central system via satellite or cellular network, where the information is processed and made available on our website. A graphic depicting the system is available.

All Real Time Water Resources Data and Web Cameras

 

STAGE AND STREAMFLOW

Water is measured and represented in two ways – stage/elevation and streamflow.

Stage is an engineering term with respect to how the water level in a river is reported. Stage is not a measurement of the actual depth of water in the river. Rather, it is a measurement used to show the change in water level in a river.

If the measurement device for water level is tied into a surveyed ground elevation (like contour lines on a topographic map) it is reported as Elevation in metres.

Some stations have been surveyed to determine their elevation relative to a national elevation reference (e.g. CGVD2013). However, several stations still report as stage. At these stations, water level is measured using a local reference point, such as a fixed ruler or a permanent marker installed in the river. The reported stage is the height of water above this local reference. Because each station’s reference point is unique, stage measurements are only meaningful at that particular location unless converted to elevation.

Streamflow is the volume of water in a river at a specific location and time. It is measured in cubic metres per second (m³/s).

It is important to note that streamflow is not directly measured at rivers – only water level. Rather, streamflow is calculated using a customized flow equation developed for each river. The flow equation is based on stage and velocity measurements, taken over an extended period and collected under a range of flow conditions. Each stage or elevation value is used in the creation of the equation to calculate flow.

The flow equation is not linear. As a result, changes in streamflow generally follow the same rising and falling pattern as water levels, but they will not always match exactly. The differences occur because of the shape of the river bottom and banks, and they are typically most noticeable during very low and very high flow conditions.

 

ICE CONDITIONS – INCREASED FLOWS, BACKWATER AND GRAPH SPIKES

During the winter months, ice formation on rivers can cause water levels to rise even though the same amount of streamflow is occurring. This causes the water level measurement instrument to report higher water levels, resulting in incorrect streamflow values being reported.

For example, consider a river that is 50 m wide, with a water level of 2.5 m and a calculated flowrate of 100 m³/s. If 10 m of ice forms along both sides of the river, the channel through which water can flow is now only 30 m. With the same 100 m³/s of water flowing through this narrower channel, the water level will rise above 2.5 m. Calculating streamflow based on this higher water level will give a value that is too high, even though the actual flow has not changed.

A temporary ice blockage downstream of a station can also affect data. An ice blockage downstream can cause water to “back up” the river, raising water levels at the station and producing inaccurate flow measurements. This condition is known as backwater effect. If the ice blockage is only for a short duration, the resulting graph may show a spike that quickly disappears. Multiple short-lived blockages can create a series of spikes on the graph.

Additionally, when the portion of the instrument that is in the river freezes or otherwise malfunctions, spikes can also appear on the graph. This can also result in a series of spikes which occur repeatedly as conditions in the river change.

Reports and Publications

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Disclaimer

Provisional Near-Real-time Streamflow and Climate Data displayed on these pages are obtained from a network of gauges maintained under the Canada-Newfoundland Hydrometric Network Agreement. The operation of the network is cost shared by federal and provincial government departments and private companies.

Due to the volume and frequent updating of the data available on this Web site the streamflow and climate data is PROVISIONAL and has not undergone quality control checks. These data may be subject to significant change.

Data are reviewed on a regular basis by Environment and Climate Change Canada and WRMD personnel to ensure accuracy. Each station record is considered PROVISIONAL until the data are published. The data are usually available within six months of the end of the water year. The publication quality data is distributed yearly by Environment and Climate Change Canada for all streamflow gauging stations in Canada.

Before using this data in making decisions that concern personal or public safety, substantial monetary expenditures, or other operational consequences, users must carefully consider the provisional nature of the information.

Information concerning the accuracy and appropriate uses of these data or concerning other hydrologic data may be obtained by contacting WRMD at water@gov.nl.ca or by calling (709) 729-2563.

Comment or Problems

To report problems or offer suggestions on improvements, please send e-mail to water@gov.nl.ca