Totally great park. I took my Golden Retriever here and she LOVED it.
The best part of the park, is by far, the swimming lake. Dogs can get into the water with a gradual slop. The water appeared to be clean enough so "all good" on that front. There was even an area where you could hose off your dog after the swim (I didn't and she didn't smell afterwards).
Best Dog park in AZ IMHO.
I've posted a video of the park here: http://tinyurl.com/3ua2sw