Look for a cloudy day.

If not windy go with a 9' 4 wt for the most fun; if windy a 5 wt.

The area immediately below the dam has lots of didymo. Keep your nymphs off the bottom or spend your time checking the hook after every cast. Swung soft hackle flies are very effective there.

The algae doesn't extend very far downstream so standard rigs work fine at the other public access points.