Beach, Beach, Beach! Who knew there would be a 'semi beach' looking place in Arizona? I didn't. This would be the closest you'll get for an Arizona beach.
The water here is not meant for swimming, so don't get all dressed up for it. Tempe Beach park is a great place to bring your dog for a walk/run or bring family for a walk or to hang out. I don't think there's place for you to BBQ, however, you can bring food for picnic. This beach/park is big, so you can have a gathering here. Bring some activities such as football, volleyball or kite to play. Just make sure not to have it end up in the water, else you'll have to get it yourself. Haha.
I would suggest to come here when the days are cool. Like I said, you can't dip your feel into the water since it's not meant for dipping. :/