Water Supply Outlook March 2010

Updated: March 11, 2010

Mountain runoff forecasts (natural volumes for March to September 2010)

Forecasts have decreased for most locations, on average by 2% since February 1 forecasts, except for the North Saskatchewan River at Edmonton, where the forecast has increased by 2%.

Milk River basin
  • Below average
Oldman River basin
  • Below to much below average for the St. Mary, Belly River and Waterton River at Waterton Park
  • Below average for Oldman River at Brocket and Lethbridge
Bow River basin
  • Below average to average for the Elbow River at Bragg Creek
  • Slightly below average for Spray Reservoir, Kananaskis River at Kananaskis and Highwood River at the Mouth
  • Below to much below average for the Bow River at Calgary and Cascade Reservoir
  • Much below average for the Bow River at Banff
Red Deer River basin
  • Below average
North Saskatchewan River basin
  • Below average for the Bighorn and Brazeau Reservoirs
  • Below to much below average for the North Saskatchewan River at Edmonton

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 May, and again in July.

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, 2010:

  • Oldman River basin: ranging from below to much below average at eight locations. Much above average at Wilkinson in the upper Oldman River basin. Below average to average at Lee Creek in the middle St. Mary River basin.
  • Bow River basin: highly variable in the Upper Bow River basin, but below average overall. Below average in the Kananaskis and Elbow River basins, and below to much below average in the Highwood River basin.
  • Red Deer, North Saskatchewan, Athabasca River basins:

    Above average to much above average in the mountains and below average to average in the foothills in the Athabasca River basin.

    Near average in the mountains and below average to average in the foothills except above average to much above average at Limestone in the North Saskatchewan River basin.

    Highly variable but generally average in the Red Deer River basin.

  • Upper Peace River basin in British Columbia: below normal, as indicated in British Columbia's Snowpack and Water Supply Outlook

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 mid-February.
  • Environment Canada map of satellite estimation of plains percent of normal snow water equivalent (SWE) as of March 1, 2010 is shown here. Although southern plains snowpack is indicated as over 200% of normal, snow water content amounts are generally only moderate or moderately high as typically there is little snow in this area.
  • 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, 2010 is available here.

Long Lead Precipitation Outlooks

Environment Canada (issued on March 1, 2010): above normal temperature and below normal precipitation for Alberta, except for normal temperature and precipitation for the southeastern corner of the province, for the March through May 2010 period.

National Oceanic and Atmospheric Administration (NOAA) (issued on February 18, 2010): Above normal temperatures and an even chance of below normal, normal or above normal precipitation in southern Alberta, for March through May 2010.

Climate indicators: The NOAA reported on March 4, 2010 that moderate to strong El Nino conditions are likely to continue into at least spring 2010.

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
Phone: (780) 427-6267