May 2020 Mini-Flood

On the weekend there were warnings to stay clear of the North Saskatchewan, because the big rain from last week was leading to a big increase in water.

Recent History

Here we the river depth and streamflow going back to 2015, and every spring/summer there are spikes.

This one was a fairly large one though, with the depth jumping from 4m on May 19th up to 7.6m on the 23rd. Along with that the streamflow increased by about 6x from 350m³/s up to 1,811m³/s.

1911+

For a bit more context here we have the full recorded history. Streamflow readings go all the way back to 1911, but unfortunately daily depth measurements only go back to 1999 (although some of the notable floods are also shown).

May 2020's 7.63m was well below the biggest floods. The great flood of June 29, 1915 was way up a 13.73m, July 19, 1986 was around 12m, and 4 other floods were close to the 10m mark.

And recently the mini-floods of 2013 reached 9.25m, 2005 hit 8.85m, 2003 hit 8.17m, and 2011 hit 7.82m.

So May 2020's mini-flood was a lot of water, but not all that unusual.

During the Year

This chart shows how the river depth and streamflow vary throughout the year.

And the mini-flood of May 2020 was definitely big enough to makes its presence known, but it's well below the really big years.

We are right in the middle of high-water season, although the really big floods usually happened in June & July.

1,800m³/s

Here is the same chart, but it is cleaned up a little bit to only show the years with streamflows of 1,800m³/s.

There have only been 19 years to get that high, most recently 2013, 2011, 2005...

Streamflow History (again)

Here's one more pretty chart which collapses all of the streamflow data for 1911-2020.

Here the various spikes are nicely visible, and you get a sense of how they are spread throughout the year, and throughout the years.

This chart can also be filtered to only show the 1,800m³/s+ years:

...and we can see that our little flood was pretty early in the year, and there might be more to come?

So that was a quick look at this recent mini-flood. If you are interested in a bit more historical context we took a deeper dive into the river data last year in: The North Saskatchewan River - from Top to Bottom