Sunday, April 10, 2011

Feet James

As attention turns once again to the Red River of the North, Winnipeg Free Press reporter Barley Kives has explained the Peggers' peculiar unit of measure:

If you're following the flood in Winnipeg this spring, you may be wondering why the city makes such a big deal about some guy named James.

Thanks to a quirk of history, the city's shorthand for the height of the Red River happens to be the "number of feet James." Unfortunately for circuses everywhere, this is not a question about a man with too many appendages.

James actually refers to the James Avenue Pumping Station, a facility on the west bank of the Red River in the Exchange District. For nearly a century, this site has been used to monitor river levels.

Originally, this data determined the operation of the St. Andrews Lock and Dam at Lockport. Measurements were live human beings and the station was staffed 24 hours a day. Now, the James Avenue station operates automatically. It's basically just a culvert with an electronic water-pressure gauge that transmits river-level data every 15 minutes. The city uses feet instead of metres to express this information, mainly for the sake of consistency. The "number of feet James" is also easier to digest than the number of feet above sea level, a far bigger number.

On Friday afternoon, the Red River in Winnipeg stood at 9.7 feet James. That's still well below flood stage, as you can see from the following milestones on the scale. . .

Zero feet James
This is the famous "normal winter ice level" in Winnipeg -- 727.6 feet (or 221.7 metres) above sea level. This level is an average of mid-winter measurements at James Avenue dating back to 1912. The actual river ice level varies from year to year.

6.5 feet James
The average summer river level in Winnipeg, again based on measurements taken over the past century. St. Andrews Lock and Dam maintains this level during years when the Red River would otherwise drop even lower.

18 feet James
While river levels above 15 feet are recorded as floods on the city's website, the city is in de facto flood mode at 18 feet James. River levels of 18 feet or higher require significant flood-mitigation efforts, such as sealing up drainage gates or sandbagging low-lying homes.

20.2 feet James
The peak of the 2005 summer flood. The Red River crested on July 3 and 4 due to unusual rains over the Canada Day weekend.

20.4 feet James
The peak of the 2006 spring flood, when the Red crested on April 7. At the time, this was the largest flood in the Red River Valley since the Flood of the Century in 1997.

22.6 feet James
The peak of the 2009 spring flood, which confounded flood forecasters who initially predicted a milder spring deluge. Ice jams downstream created two smaller crests before the Red finally peaked on April 15.

24.5 feet James
The peak of the Flood of the Century. The Red River crested on May 3, to the relief of Winnipeggers who watched the same deluge destroy downtown Grand Forks, N.D. and inundate Ste. Agathe.

30.3 feet James
The peak of the 1950 flood, the most destructive disaster in Winnipeg's history. The Red crested on May 19 and did not recede below the flood stage until mid-June of that year. The flood forced 100,000 people to evacuate and caused $600 million in damage, in Winnipeg alone.

34.7 feet James
Estimated peak of the 1852 spring flood in what was then the Red River settlement.

EcoInformatics International -- based in Ottawa -- has done a fine job compiling historic & contemporary GIS data for Glacial Lake Agassiz. Click here for access.

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