Waterman, Shoshone is almost always doable. They use around 1000 cfs for the hydro plant, and have some of the most senior water rights in Colorado. This is good news for us, because otherwise, the Colorado river would be dry and the water would be in Denver or somewhere else. You can almost always count on being able to run it, there are a bunch of die hards who even run it on New Years. If for some reason the plant is doing maintaince, it might be an exception to the rule for the flows, but anything over about 800cfs should be fine for your raft.