Water Supply Outlook March 2018

Updated: March 8, 2018

Mountain runoff forecasts (natural volumes for March to September 2018)

Milk River basin
  • Below average to above average for the March to September period
Oldman River basin
  • Above average to much above average for the March to September period
Bow River basin
  • Average to much above average for the March to September period
Red Deer River basin
  • Below average for the March to September period
North Saskatchewan River basin
  • Average to much above average for the March to September period

Precipitation can have a major impact on water supply between now and the end of September. The forecasts above assume that precipitation over the remainder of the winter period and through the summer will be normal. The range of possible precipitation scenarios is large however, and as a result, probable range forecasts and a minimal precipitation forecast of natural runoff volume are also provided for each individual basin. Since more information becomes known over time, forecast ranges will narrow. Streamflow volume forecasts are updated monthly from February to August (dependent on flood events).

Check our Forecaster's Comments throughout the month for updated information regarding runoff conditions.

Mountain snowpack

Snow accumulations measured in the mountains as of March 1, 2018:

  • Oldman River basin: above normal to much above normal, ranging from 113% at Allison Pass to 159% at Akamina Pass (6 sites surveyed; Akamina Pass snow pillow offline until 2019 season due to Waterton Fire).
  • Bow River basin: above average to much above average, ranging from 110% at Lost Creek South and Tent Ridge to 139% at Chateau Lawn (21 sites surveyed).
  • Red Deer, North Saskatchewan, Athabasca River basins:

    Red Deer River basin: generally much above average, Gable Mountain (133%) and McConnell Creek (121%) (2 sites surveyed).

    North Saskatchewan River basin: above average to much above average, ranging from 112% at Nigel Creek to 146% at Limestone Ridge (4 sites surveyed).

    Athabasca River basin: above average at Marmot-Jasper (112%) and Sunwapta Falls (118%) and much above average at Hinton (140%) (3 sites surveyed).

  • Upper Peace River basin in British Columbia: as indicated in British Columbia's Snow Survey and Water Supply Bulletin

Mountain snowpack is an important source of water supply to reservoirs in the spring. Accumulation at this time of year typically accounts for nearly three-quarters of the seasonal total.

Plains Spring Snowmelt Runoff Forecasts

Conditions are variable across the province, please refer to the map in the Plains Runoff Forecast section of our Maps and Data Summaries webpage.

Plains snowpack

  • Map of Snow course measurements taken at the end of February and the beginning of March in many areas of central and northern Alberta. Cypress Hills snow measurements were taken in late-February.
  • Environment Canada map of satellite estimation of plains snow water equivalent (SWE) as of March 6, 2018 is shown here.
  • Alberta Agriculture publishes maps of modelled plains snow accumulations and accumulations as compared to normal.


Contoured maps of precipitation amounts and as a percent of normal for the past month and for current and recent seasons are available here. Maps of precipitation amounts for the most recent day, week and month to date are available here.

Soil Moisture

Alberta Agriculture models soil moisture for non-mountainous, agricultural areas of Alberta. Modelled soil moisture compared to average as of February 28, 2018 is available here.

Long Lead Precipitation Outlooks

Environment Canada (issued on February 28, 2018): Temperatures is forecast to be normal for the March through May 2018 period. Precipitation is forecast to be above normal for the major portion of northern Alberta and normal for rest of the province for the March through May 2018 period.

National Oceanic and Atmospheric Administration (NOAA) (issued on February 18, 2018): below normal temperature is forecast for southern Alberta for March through May 2018. Above normal precipitation is forecast for southern Alberta for March through May 2018.

Climate indicators: The NOAA reported on February 8, 2018 that a transition from La Niña to ENSO-neutral is most likely during the Northern Hemisphere spring (~55% chance of ENSO-neutral during the March-May season).

Note that forecasting weather for such a long time period into the future is very difficult, and so the historical accuracy has been variable, dependent on location and time period, and is often low, more so for precipitation than temperature. Environment Canada provides an assessment of their forecast method's historical accuracy on their website.

Reservoir storage

Water storage volumes in the major irrigation and hydroelectric reservoirs of the Milk, Oldman, Bow, Red Deer North Saskatchewan, and Athabasca River basins is updated each weekday and is available in the Provincial Reservoir Storage Summary.


Background information on the Water Supply Outlook is available in Frequently Asked Questions

Media Contact:
Communications Division, Alberta Environment and Parks
Phone: (780) 427-8636