that's pretty good justification for them removing the bridge! I wonder what it looks like today.
So the water level station is working. And so, your question is answered below (assuming that the x-axis of this graph is set such that the date is positioned at 00:00 each day).
Prior to today I wasn't sure that this station was in fact the Twin Bridges one (I thought it may be further downstream) but there's a map on the water survey website that confirms the location.
So - check it out! http://wateroffice.ec.gc.ca/report/report_e.html?type=realTime[HTML_REMOVED]stn=08GA030
I looked at the data table - the water level in my photo above is 6.6m approx. The datum is arbitrary, so this does not mean 6.6m above sea level or anything. But I think the overflow level at the path is probably around 8m on that graph.
As an ex-hydrologist, it is pretty luxurious to have a water level station right at the point of interest, that never happens! I am going to dig into the data to see how it looked right when the rockslide happened. So far, no go - it appears that the station may have been out of service, and they turned it on a day or two after the slide. You can see below that the record starts after the slide. The blue triangles are where Water Survey of Canada has manually measured and recorded the water level.
The paths must have been under water immediately after the event, the peak levels is 4m (12 ft) higher than in my photo!
edit see my post on next page re: initial levels on the graoj