Three Creek Lake is good, but I would say maybe not as fishy as it’s been the last several seasons. Look for the Callibaetis hatch in the afternoon, with spinner falls likely in the morning and the evening and a possible 2nd emergence of duns coming off in the evening. Also, midges hatch in the evening this time of year and a Lady McConnell and McKittrick’s Moment Midge will be good when the fish are eating the emerging adults. This is the time of year we rely on the Black X Caddis #16 for the Long Horned Sedge Emergers. It is essential. 
We’ve been having great luck this season with a new balanced leech that has a leather tail and a chartreuse bead. It’s a Vampire Leech with a suede tail. Try it. 
Scuds in low light, and Damsel nymphs in mid day light will be good. Red PT has been probably our #1 nymph this season with the Vampire Leech under the indicator.