This is the link for the flow from Chatfeild Dam it is the gauge for the 470 put in.
Right now it reads 20cfs while Union says 57cfs.
When the Chatfeild gauge is at 125ish there is enough water to make it to the grill but alittle shallow it is better at 200+ and a few of the drops have some surf feature 200+400ish cfs most wash out over this.
While the first hole below 470 is surfable at 99cfs and up, it has a smooth bottom kind of like the Bleacher hole at Golden but with a nice V-wave as it gets bigger.
Wish they would start draining the lake I live 5 min from the 470 hole.