[Help] Installing water "inlet" into existing plastic reservoir DIY

I've got one of these pet fountains:

http://ift.tt/12SdK4X

and it's placed next to my refrigerator and water line. I'd like to put a hole in the top of the water reservoir and attach it to the water feed with an inline valve. The T, piping, and valves seem pretty straight forward, but I'm drawing a blank on what/how to get the line into the plastic.

Clearly, I'd need to drill out a hole, but what's the part I'd use to secure the water line into the reservoir?

Thanks!

Submitted August 24, 2015 at 03:28AM by chuyskywalker http://ift.tt/1Jq0HG7 DIY