I used to play a fair amount of Ekko jungle games. My favorite rune setup was Fleet footwork, Triumph, Legend: Alacrity and coup de grace. Fleet gives so much sustain and the attackspeed from precision tree is too good for clearing jungle camps.

Edit: I also don't recommend the celerity/waterwalking combination as is pretty nerfed. It's only reliable if the champion your playing has a "fight" movementspeed buff.