Smith River - I hope you get some current info but I thought I might impart some 40yr old info. I grew up in Danville VA and we fished the Smith a lot back in the mid 60's. At that time the area that is now the trophy section was one of the most polluted parts of the river. Those manufacturing plants closed in the 70's and the river came back strong. It is tail water and the river probably rises 3' when they are generating. I believe there is a number to get the schedule for that generation. We always fished the upper section closer to the dam but that was because there was no manufacturing there. Back then there was still trash in the water and I can still remember always getting a trout to rise over a bed spring - no nymphs over the bed spring.
Dan River - If Duke Power reported on a spill it was on the part of the river when it crosses back into NC. The river originates in VA up near the Blue Ridge Parkway and US Rt 58 (Meadows of the Dan). The city of Danville controls two reservoirs up there and they pipe the water about 6 miles down the hill
to an area called Kibler Valley. This is also tail water and when they are generating it probably isn't fishable. There is a special reg section from the powerhouse up to the dam that is probably fishable now (about 6 miles). There is a number available to call for the generating schedule. The stream below the powerhouse
get a lot of kayakers in the summer the the water is high. Back in the late 60's I camped at the lower dam. The city of Danville will let you have a permit to camp there. The lake is very narrow and remote (very Deliverance like) and the stream that connects the lower lake to the upper is accessible by canoe/yak from the lower lake. I saw a few local bank fishing and given the moonshine heritage of that part of VA, we politely left them alone. Younger brother, John, might chime in here with more details. A lot of boonies in that part of the world.