Water levels on Lower Hoki and Karamea


I was wondering if anyone knew of how to judge if these two runs(lower hoki and karamea) are at a good level without having to go look visually. I know they both have gauges on the west coast regional council webpage, but I can't make any logical correlation between reading those internet gauges and runnability for the two runs. I'm just curious because I'm visiting NZ in a short while and I'm planning on leading a trip for some friends.

What would you guys do if you needed to check flows?