Map of Streamflow Return Periods for All WSC Stations

Colour Scheme for Return Periods:

Note of Data Sources:

  1. The river discharges and water levels are from Water Survey of Canada (Disclaimer for Hydrometric Information and Terms and conditions) and represent the readings at the time displayed in the parentheses below the map title.
  2. Return Periods are expressed in years and reflect the discharge rate associated with the statistical probability of the annual maximum discharge of the historical record for a given station. Data shown on the map indicate the current range of discharge at a site for the day.

Users should use the information on this map with caution and do so at their own risk.

The data are collected in near-real-time by automated monitors at numerous remote locations and are unverified. The data are preliminary, and may be changed upon subsequent review. Some data may be wrong. It is not uncommon for individual water level recorders to give false readings, due to local conditions. The return period estimates presented on this map are preliminary and are often based on limited data. They should be considered as reference values only, by which to evaluate the current readings. They should not be used for design or other purposes. Users of this data must accept all responsibility for the use and interpretation.


  1. Home of River Forecast Centre
  2. Current Streamflow Conditions and Flood Forecast Modeling
  3. Current Advisories and Flood Warnings
  4. Map of 10-day Forecast of Daily Average Temperature and 24H Precipitation (10 page PDF file)
  5. CLEVER Model 10-day Forecast of Discharges and Return Periods
  6. COFFEE Model 5-day Forecast of Discharges and Return Periods
  7. Map of Low Streamflow Percent of Mean Annual Discharge
  8. Map of 7-Day Average Streamflow