Water Supply Outlook November 2015
Updated: November 12, 2015
Recorded natural runoff volumes from March to September 2015
Natural runoff volumes from March to September 2015 were generally much below average in the Milk River, Oldman River, Bow River, Red Deer and the North Saskatchewan River basin with the exception of the Bighorn Reach in the North Saskatchewan which was average.
Natural runoff volumes recorded from March to September 2015 for rivers in the Milk River basin ranked between 5 and 27 in 99 years of record. Rankings are from lowest to highest. The rivers in the Oldman River basin ranked between 15 and 22 in 99 years of record. The rivers in the Bow River basin ranked between 2 and 31 in 99 years of record. The rivers in the Red Deer River basin ranked between 4 and 5 in 99 years of record. The rivers in the North Saskatchewan River basin ranked between 6 and 56 in 100 years of record.
The average difference between all forecasts from the beginning of the year through August and the preliminary recorded natural volumes were 49% for the Milk River basin, 14% for the Oldman River basin, 13% for the Bow River basin, 23% for the Red Deer River basin, and 16% for the North Saskatchewan River basin.
The forecast accuracy between the first month’s forecast and the May forecast saw, on average, an increase in accuracy from 26% to 22% for the average difference between recorded and forecasted volumes.
Milk River basin- March - September recorded volumes were much below average for Milk River at Milk River, and Milk River at Eastern Crossing and below average for Milk River at Western Crossing.
- The naturalized flow volumes would suggest that there were significant channel losses or unaccounted for diversions between Western Crossing and Milk River.
- The recorded volumes were much lower than was forecasted during the January to May water supply outlook. The average difference between forecasted and recorded volumes was 49%.
- March - September recorded volumes were much below average for the Belly, Waterton and the St. Mary Rivers and below average for the Oldman River.
- The recorded volumes were lower than was forecasted during the January to May water supply outlook. The average difference between forecasted and recorded volumes was 14%.
- March - September recorded volumes were much below average for all reaches except the Elbow and Highwood Rivers which were below average.
- The recorded volumes were lower than was forecasted. The difference between forecast and recorded volumes were on average 13%.
- March - September recorded volumes were much below average for the Red Deer River at Dickson Dam and the City of Red Deer.
- The recorded volumes were lower than was forecasted, and on average the difference between the forecasted and recorded volumes was 23%.
- March - September recorded volumes were average for Lake Abraham (Bighorn Reservoir), much below average for the Brazeau Reservoir and for the North Saskatchewan River at Edmonton.
- The recorded volumes were higher than forecast for Lake Abraham and the North Saskatchewan River at Edmonton, and lower than forecast for the Brazeau Reservoir. On average, the difference between the forecasted and recorded volumes was 16%.
Note: The recorded 2015 natural flow volumes are preliminary and subject to change.
Check our Forecaster's Comments for updated information regarding runoff conditions.
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 October 31, 2015 is available here.
Long Lead Precipitation Outlooks
Environment Canada (issued on October 31, 2015): temperature and precipitation for the November 2015 through January 2016 period:
- normal precipitation for all of Alberta.
- above normal temperatures for all of Alberta.
National Oceanic and Atmospheric Administration (NOAA) (issued on October 15, 2015): equal chance of above normal, normal and below normal temperatures for the province except for extreme southern Alberta, which is above normal. There is an equal chance of above normal, normal and below normal precipitation for the province except for extreme southern Alberta, which is below normal for the November 2015 through January 2016 period.
Climate indicators: The NOAA reported on October 8, 2015 there is an approximately 95% chance that El Niño will continue through winter 2015-16, gradually weakening through spring 2016.
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
