Web services offered by the Canadian Hydrographic Service

Web services for accessing official data on navigating modelled surface currents and water levels.

Terms and Conditions for use of the Tides, currents and water levels public website

If you would like to use the web services offered by the Canadian Hydrographic Service and the Tides, currents and water levels public website, please read this licence agreement.

If you agree with the terms and conditions of the Canadian Hydrographic Service and the Tides, currents and water levels public website licence agreement, please click on the "I agree" button.

On this page

Rest-API Documentation

CHS is currently undergoing a transformation process in all its product and service delivery activities. Two of the key elements that CHS is working on are the modernization of the water level database (observations, forecasts, predictions) and the development of new services for the dissemination of these data including this REST-API programming interface.

To receive information and notices of updates regarding this interface, please send your name and email to chsinfo@dfo-mpo.gc.ca.

To familiarize yourself with this new public API, users can consult the documentation available in English only on the following website: https://api-iwls.dfo-mpo.gc.ca/swagger-ui.html.


  1. To find the IDs of your stations of interest: https://api-iwls.dfo-mpo.gc.ca/api/v1/stations.
  2. Use the following query to obtain the official water levels (wlo) for Vieux-Québec station (ID code: 5cebf1e23d0f4a073c4bc0f6) from October 1 to 2, 2020: https://api-iwls.dfo-mpo.gc.ca/api/v1/stations/5cebf1e23d0f4a073c4bc0f6/data?time-series-code=wlo&from=2020-10-01T00:00:00Z&to=2020-10-01T00:30:00Z
  3. Replace the station ID "5cebf1e23d0f4a073c4bc0f6" with your station of interest.
  4. Change the value of the "Time-series-code" parameter to use either:
    • wlo – Water level observations
    • wlf or wlf-spine – Forecasts at operational stations only
    • wlp – Predictions (15 minutes)
    • wlp-hilo – Highs and Lows predictions
  5. Adjust the time period "From" and "To" using the ISO 8061 UTC format.

Quality control - qcFlagCode

The indicators used at all quality control levels are based on UNESCO Ocean Data Standards

Value Flag short name Definition
1 Good Passed documented required QC tests
2 Not evaluated, not available or unknown Used for data when no QC test performed or the information on quality is not available
3 Questionable/suspect Failed non-critical documented metric or subjective test(s)
4 Bad Failed critical documented QC test(s) or as assigned by the data provider
9 Missing data Used as place holder when data are missing

Web service providing access to water level SPINE forecasts

Technical specifications for accessing this service.

This document describes the technical specifications for accessing the Web-based water level forecasting and interpolation service between Montreal and Saint-Joseph-de-la-Rive commonly known as SPINE.


The SPINE web-based forecasting service was developed by the Canadian Hydrographic Service (CHS) and is available free of charge under licence. This system allows to obtain water levels at a time and position specified by the user, up to 30 days in the future, for the navigation channel of the St. Lawrence River between the Port of Montreal and Saint-Joseph-de-la-Rive.

This system is based, in part, on water level forecasts derived from a hydrodynamic model that takes various weather conditions into account and, in part, on real-time observations made by the network of permanent water level recorders. To increase their accuracy, digital model forecasts are adjusted according to water level observations for the entire area. A precision matrix is also provided for forecast data.

To access this Web service, simply follow the steps described in these technical specifications.

Access and restrictions

Please take a moment to read through the licence.


The Web service use SOAP and XML as their communication protocol and the English language for method calling and data exchange. The service has an XML description readable in WSDL (i.e. https://ws-shc.qc.dfo-mpo.gc.ca/spine?wsdl). This description is useful for automatically generating code (with tools such as WSDL2Java from Apache Axis) to communicate with the services.

Access to official data for navigating modelled surface currents

The Canadian Hydrographic Service (CHS), in collaboration with the Operational Oceanography scientific team of Fisheries and Oceans Canada, created 3 web mapping services for surface currents. These web services are also available free of charge under licence, and include:

  • A WMS that produces dynamic images of the data according to the specified parameters
  • A WFS that recovers the raw data behind the images
  • A WCS that recovers raw data from only the raster layers

To access these web services, simply follow the steps described in these technical specifications.

Geographic coverage

Web surface current services disseminate the results of various current forecast models. Each model covers a geographic area and produces data based on unique parameters, such as the:

  • frequency of forecast updates
  • the level of detail (spatial and temporal resolution)
  • temporal scope (number of days in the future)

The first two models put into operation cover the Gulf of St. Lawrence and the St. Lawrence Estuary. Other models across the country will be added over time.

Gulf of St. Lawrence

Gulf of St. Lawrence

The forecasts of surface currents in the Gulf of St. Lawrence are extracted from a three-dimensional ocean model coupled to the Canadian Meteorological Service's atmospheric forecast model (Environment Canada). The ocean model integrates the:

  • sea ice
  • influence of tides
  • freshwater runoff
  • atmospheric forcing

The ocean and atmospheric models provide daily forecasts for the upcoming 48 hours. The ocean model results have been validated within scientific and operational programs of Fisheries and Oceans Canada. The validation includes a number of comparisons with various ocean measurements: currents, water levels, water temperature and salinity, and sea-ice drift, concentration and thickness.

The model's forcing data include:

  • Tides at Cabot and Belle-Isle straits;
  • Freshwater runoff at Québec City;
  • Atmospheric forecasts from the Global Environmental Multiscale (GEM) model (Canadian Meteorological Centre, Meteorological Service of Canada, Environment Canada), which provide data on:
    • winds
    • air temperature
    • cloud cover
    • relative humidity
  • Sea ice observations integrated into daily charts from the Canadian Ice Service, Environment Canada.
St. Lawrence Estuary, from Trois-Rivières to Cap de Bon-Désir

St. Lawrence Estuary, from Trois-Rivières to Cap de Bon-Désir

The surface current forecasts for the St. Lawrence Estuary result from a 3D numerical model. The ocean model integrates tidal influence and mean freshwater runoff from the St. Lawrence River (no influence of the spring freshet) without wind forcing. Model results were validated with a statistically significant series of drifting buoy tracks in calm weather conditions.

Tides are responsible for a high percentage of the energy from currents in this region. However, the forecasts must be used with caution during intense or extreme wind conditions and in spring freshet conditions.