Water Supply Outlook June 2015

Updated: June 9, 2015

Mountain runoff forecasts (natural volumes for March to September 2015)

Milk River basin
  • Below average for the Milk River at Western Crossing and Milk River at Milk River for the March to September period
  • Much below average for the Milk River at Eastern Crossing for the March to September period
  • Below average for June to September
  • March-May recorded volumes are below average for the Milk River at Western Crossing and much below average for the Milk River at Milk River and Milk River at Eastern Crossing

Oldman River basin
  • Below average for the St. Mary River, Belly River, Waterton River and Oldman River at Lethbridge for the March to September period
  • Average for the Oldman River near Brocket for the March to September period
  • Below average for June to September.
  • March-May recorded volumes are average

Bow River basin
  • Below average for the March to September period
  • Below average for June to September
  • March-May recorded volumes are below average for Lake Minnewanka and Spray River near Banff; average for Bow River at Calgary, Elbow River and Bow River at Banff; and above average for the Kananaskis and Highwood Rivers

Red Deer River basin

North Saskatchewan River basin
  • Much below average for Lake Abraham (Bighorn Reservoir) for the March to September period
  • Below average for Brazeau Reservoir and North Saskatchewan River at Edmonton for the March to September period
  • Much below average for Lake Abraham (Bighorn Reservoir) and below average for Brazeau Reservoir and North Saskatchewan River at Edmonton for June to September
  • March-May recorded volumes are above average for Lake Abraham (Bighorn Reservoir) and below average for Brazeau Reservoir and 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 June 1, 2015:

  • Oldman River basin: Much below average to below average: ranges from 0% (Akamina Pass) to 38% (Gardiner Creek) of average.
  • Bow River basin: Much below average to below average: ranges from 0% (Tent Ridge) to 75% (Katherine Lake) of average.
  • Red Deer, North Saskatchewan River basins:

    Much below average to below average for the Red Deer River basin: two sites surveyed in this basin – Gable Mountain at 0% and McConnell Creek at 0% of average.

    Below average to average for the North Saskatchewan River basin: ranges from 89% (Limestone Ridge Pillow) to 0% (Limestone Ridge Snow Survey) 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 (issued in March and April each year)

Plains Snowpack (issued in March and April each year; Cypress Hills mid to late January and February)

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 May 31, 2015 is available here.

Long Lead Precipitation Outlooks

Environment Canada (issued on May 31, 2015): Temperatures is forecast to be above normal across the entire province for the June through August 2015 period. Precipitation is forecast to be normal across the province, except the southern portion of the province excluding Cypress Hill areas where it is forecast to be below normal.

National Oceanic and Atmospheric Administration (NOAA) (issued on May 21, 2015): Above normal temperatures in the province for June to August 2015 and an equal chance of below normal, normal or above normal precipitation for June to August 2015.

Climate indicators: The NOAA reported on May 14, 2015 that there is an approximately 90% chance that El Niño will continue through Northern Hemisphere summer 2015, and a greater than 80% chance it will last through 2015.

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) 427-6267