Water Supply Outlook July 2017

Updated: July 7, 2017

Mountain runoff forecasts (natural volumes for March to September 2017)

Milk River basin Oldman River basin Bow River basin
  • Average to much above average for the March to September 2017 period
  • Average to much above average, except for the Elbow and Highwood Rivers, which are below average for July to September
  • March-June recorded volumes are average to much above average
Red Deer River basin North Saskatchewan River basin

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 (issued in December to June each year)

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)


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 July 5, 2017 is available here.

Long Lead Precipitation Outlooks

Environment and Climate Change Canada (issued on June 30, 2017): Temperature is forecast to be above normal for the July through September 2017 period, for the entire province. Precipitation is forecast to be above normal for the July through September 2017 period in northern Alberta, below normal in central and southern Alberta.

National Oceanic and Atmospheric Administration (NOAA) (issued on June 15, 2017): An equal chance of below normal, normal or above normal temperature in southern Alberta for July through September 2017. Above normal precipitation in southern Alberta for July through September 2017.

Climate indicators : The NOAA reported on June 8, 2017 that ENSO-neutral is favored (50 to ~55% chance) through the Northern Hemisphere fall 2017.

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