June thru December is a definite do not hike period for these hikes. I wouldn't even consider it. Flash floods are regular this tine of year.
285-325cfs would be a pretty good wall of water, easily 10 feet high or more.
Good thing you canceled.
“Life is tough, but it’s tougher if you’re stupid”
John Wayne as Sergeant John M. Stryker, USMC in “The Sands of Iwo Jima”