Water Supply Outlook April 2016

Updated: April 11, 2016

Mountain runoff forecasts (natural volumes for March to September 2016)

Milk River basin

Oldman River basin
  • Below average for the St. Mary River and Oldman River at Lethbridge and near Brocket for the March to September period
  • Average for the Belly River and Waterton River for the March to September period
  • Below average for the St. Mary River and Oldman River at Lethbridge and near Brocket for April to September, except for the Belly River and Waterton River which is average
  • March recorded volumes are below average to above average

Bow River basin
  • Below average for the Bow River at Banff, Cascade Reservoir and Highwood River for the March to September period.
  • Average for the Spray River, Kananaskis River, Bow River at Calgary and Elbow River for the March to September period.
  • Below average for the Bow River at Banff, Cascade Reservoir and Highwood River for April to September, except for the Spray River, Kananaskis River, Bow River at Calgary and Elbow River which is average
  • March recorded volumes are below average to much above average

Red Deer River basin

North Saskatchewan River basin
  • Below average for Lake Abraham and North Saskatchewan River at Edmonton for the March to September period
  • Much below average for Brazeau Reservoir for the March to September period
  • Much below average for Brazeau Reservoir for April to September, except for Lake Abraham and North Saskatchewan River at Edmonton which is below average
  • March recorded volumes are average to much above average to below average

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 April 1, 2016:

  • Oldman River basin: Much below average to average: ranges between 0% (Lee Creek) and 98% (South Racehorse Creek) of average.
  • Bow River basin: Much below average to above average: ranges between 79% (Cuthead Lake) and 111% (Mud Lake and Chateau Lawn) of average.
  • Red Deer, North Saskatchewan, Athabasca River basins:

    Much below average for the Red Deer River basin: approximately 75% of average.

    Much below average to average for the North Saskatchewan River basin: ranges between 10% (Brown Creek) and 93% (Nigel Creek) of average.

    Below average to much above average for the Athabasca River basin: ranges between 86% (Marmot-Jasper) and 124% (Hinton) of average.

  • 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

Runoff is either complete or is expected to be much below average, 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 March and the beginning of April in many areas of central and northern Alberta.
  • Environment Canada map of satellite estimation of plains snow water equivalent (SWE) as of April 8, 2016 is shown here.
  • Alberta Agriculture publishes maps of modelled plains snow accumulations and accumulations as compared to normal.

Precipitation

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 March 31, 2016 is available here.

Long Lead Precipitation Outlooks

Environment Canada (issued on March 31, 2016): Temperatures is forecast to be above normal across the entire province for the April through June 2016 period. Precipitation is forecast to be above normal in southern Alberta and normal for the rest of the province for the April through June 2016 period.

National Oceanic and Atmospheric Administration (NOAA) (issued on March 17, 2016): An equal chance of below normal, normal or above normal precipitation in southern Alberta except for the southwest corner of Alberta, which is below normal for April to June 2016. Above normal temperatures in southern Alberta for April to June 2016.

Climate indicators: The NOAA reported on March 10, 2016 that a transition to ENSO-neutral is likely during late Northern Hemisphere spring or early summer 2016, with close to a 50% chance for La Niña conditions to develop by the fall.

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.

Questions

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