https://www.theprogress.com/communit...in-chilliwack/
More pics at the link.
Interestingly this story discusses an 1894 flood and mentions the Mission gauge reading of 25.75 feet, which is 7.84m. I took a look, and the peak was ~5.5m earlier today. Now, I know you can in no way directly compare them, given all the development now, river changes etc. But it's certainly possible that was a bigger event. In 1948 it was said to be measured at 7.6m(though it doesn't specifically say the Mission gauge.)
https://wateroffice.ec.gc.ca/report/...ml?stn=08MH024
Anyway, always find it interesting to look at the historical context of these events, and how little we learn. Presumably we've just decided to accept these things occasionally.