Perspective on Churchill River Levels

Recently a fellow giving a presentation at a Saskatoon Canoe Club event made the statement that during his trip this summer up to Surf City, the Churchill River was at the highest water level seen since the 1970's. At the time, I didn't think that sounded correct so I checked, and I was right. Things were higher in '05 and and nearly the same '06, the years we went up to Hayman Lake and Mountain Lake, respectively. On July 30th, 1974 the river peaked at 932 m³/sec! The highest it has been since then was 820 m³/sec on August 7th, 2005. The early 1990's were low water years on the Churchill and the record low year was in 1993 with a peak flow of just 118 m³/sec. Starting in September of 1992 and for 18 months straight record lows were recorded. I would be curious to know how Otter Rapids, Sluice Falls, and Surf City looked in these low flows (Jay was frequenting this area at that time).

Here is one of Rob's pictures from '05 when Otter Rapids, just downstream from the photo location, was running at 690 m³/sec (down a fair bit from the peak):

Here is the same sign again in one of Bryan's pictures from a NSE family trip at the end of July in '09 when water levels were about 705 m³/sec:

For our own future reference, I've recorded some of the data from our previous 9 trips here.

Values are from data recorded at the metering station above Otter Rapids and are gleaned from the Environment Canada Water Survey Real-Time Hydrometric Data website and the Sask Watershed Authority web site. Both of these sites are very handy for trip planning. Temperatures reported are water temperatures.

• September 3-7, 2011 - 557 m³/sec (and dropping); 17.2°C; 2.48 metres. Peak was ~Aug 19 at 2.63 meters and 612 m³/sec. (Stanley Mission - Twin/Robertson Falls)
• September 3-9, 2010 - 336 m³/sec; 15.2°C; 1.76 metres. Peak was Aug 13 at 1.84 meters or approximately 347 m³/sec (Sandfly Lake - Missinipe)
• September 4-7, 2009 - 590 m³/sec; 17.6°C; 2.55 metres. Peak was ~Aug 6 at 2.84 meters or approximately 730 m³/sec*. (Missinipe - Robertson Falls)
• August 29-September 1, 2008 - 358 m³/sec; 17.2°C; 1.81 metres. Peak was June 7 at 2.27 meters or 494 m³/sec.(Barker Lake)
• September 1-4, 2007 - 320 m³/sec; ?°C; ? metres. Peak was May 26 at 496 m³/sec. (Corner Rapids)
• September 2-5, 2006 - 625 m³/sec; 17.1°C; 2.6 metres. Peak was Aug 16 at 713 m³/sec. (Stanley - Twin Falls)
• June 2-5, 2005 - 690 m³/sec; 10.0°C; 2.68 metres. Peak was Aug 7 at 820 m³/sec. (Hayman Lake)
• September 9-13, 2004 - 340 m³/sec; 1.56 m; 12.5°C. Peak was July 18 at 439 m³/sec. (Missinipe - Robertson Falls)
• September 4-7, 2003 - 250 m³/sec. Peak was July 23 at 282 m³/sec. (Devil Lake - Corner Rapids)
• June, 2002 - 150 m³/sec. Peak was on Oct 14 at 249 m³/sec. (Devil Lake)
• June, 2001 - 250 m³/sec. Peak was Aug 18 at 311 m³/sec. (Stanley - Nistowiak Falls)

I've just been playing around with the graphing feature in Google Documents. The neat thing about posting the graph this way, is that I can edit the graph, change or add data and it will update here. It's not the most visually appealing bar graph I have ever made. but it works.

Mean water flow at Otter Rapids for early June and early September almost the same at approximately 310 m³/second. In June this value is on the increase (to 325 m³/sec by late June) and in September it's on the decrease (to 300 m³/sec by mid-month). The mean peaks on about July 30th with a discharge of approximately 375 m³/sec. So, the average flow is pretty steady over the summer. However, in any individual year it can peak earlier or later and change much more abruptly. Still, this gives us some values to go by in determining what is "normal" for the region we most frequently paddle.

This graph should give the current report for Otter Rapids from the Saskatchewan Watershed Authority:

Approximate location of the water metering station at Otter Rapids (you pass it on the portage):

View Larger Map

*The data provided by Environment Canada for 2009 is incomplete at the time of writing with respect to discharge values (m³/sec). Based on the water level (m) we can determine that the peak was on around August 6th, 2009. Based on that, I extrapolated the curve from those dates where values are available and arrived at a peak value of approximately 730 m³/sec. The recorded water level during this period was very uniform so I have some confidence in the extrapolated value and can be certain that the discharge level did not spike during the data gap.