It appears that we have mother nature to blame for the flows dropping right before the spawn really happens. According to the Colorado Division of Wildlife the rain we so unpleasantly received the last couple of months has the lower city reservoirs to full to accept any more water from the high country.
The current flow rates are:
11 Mile Canyon - 36.5 cfs
Dream Stream - 34.3 cfs
Deckers/Cheesman Canyon - 150 cfs
Arkansas River below Pueblo - 208 cfs but has been going through drastic fluctuations over the last couple months...
Obviously your best options are Deckers/Cheesman Canyon or the Arkansas if the flows stay steady, but water temps are cool enough in 11 Mile and the Dream Stream to fish. Just don't cast to any trout on spawning beds, and focus your attention towards the backs of deeper pools in order to catch those rainbows looking for eggs to drop. Land fish as quickly as possible and handle them as little as possible!
Your other options are to fish any one of the many great lakes and reservoirs we have. The Mackinaw should be going strong at Rampart res. Streamers and egg patterns will do the trick. I hear the upper Arkansas has been fishing great as well.