It's a good question, and it definitely varies from region to region. The "creeks" in the NW and NorCal would compare to sections on the Poudre or Ark.
For Colorado, I think it comes down to the quality of the moves in the riverbed- at certain levels, The Numbers have "creeky" moves. Generally, I think that once you step above 100 ft/mi + below 1000 cfs, you're more into the field of creeking. However, lots of variables apply, and I'm sure others have their own definitions.
So, I think the Chutes section does have a creek "feel", add it more gradient directly above and below - then you would have to link a number of technical moves; that's creeking.