not a sluice, but a true spillway, as Todd said, can show running 300cfs, if can be out of the generator house (cold water) or down the spillway, or a little of both, for around 3-4 years now, US Fish and Game are "saving a Rock Darter and Mussel" near the Alabama line, reason for the unorthodox release schedules. In years past I could about tell you what to expect, that is all out the window now. US Fish says just and TVA ask how high.