i can only assume you are new to the area, so lets get you edumacated. the eddyflower "south canyon wave" description and gauge is for the naturally forming wave only and it is correct that the flow is too low currently for the surf wave to form. the eddyflower description is spot on, as the wave is just starting to form at 3000, is best at 3500 to 3700, and generally washes out above 4000. seem to be lots of opinions about what is the high and low end to make visiting worth while, but most agree that 3600 is oh so nice. most kayak outfitters in the area call the wave train that is always present at the location of the south canyon wave "graduation rapid" b/c it is the last rapid they run with their newbie classes before they take out.
the south canyon wave "run" is only about 100 yards long, so if you are looking for info on the common river run below GWS check out the eddyflower "grizzly to new castle" description. the gauge on this is only valid for the upper half of the run in the canyon from grizzly to GWS, as below GWS the fork dumps in and the gauge for "south canyon wave" or "glenwood play park" applies. really only two things to be heads up for below the play park, graduation rapid mentioned above and dinosaur hole. take out at either the gravel parking lot/river access at the south canyon exit from i70 (take out river right, a little downstream of graduation rapid), the east bound i70 highway pull off around mile marker 107 that has a boat ramp (take out/ramp river right, usually lots of trucks with boat trailers parked here), or all the way to the new castle exit for a boat ramp just downstream from the bridge at the exit (boat ramp river left).
edna obviously doesn't live in the area b/c her post has confused the "glenwood play park" man-made feature with the "south canyon wave" that is mother nature's damn fine handy work. the man-made stuff was designed to work at most all flows, but nature only lets you ride a few times a year.
and now you know.