Coolant leak at the water pipe- I think?

[isotyph]

First, my apologies for the horrendous photos!
My '05 automatic hatchback is leaking coolant like no other, to the point that it can't be driven anymore. I've ruled out the radiator and water pump- both have been replaced, and I think I've located the coolant to the hose on the back of the engine.

I believe this hose is the water hose, #13 on the diagram, if not also maybe #17. Can anyone verify that this is indeed a part on the '05? Thanks for your help!