We just finished staying at Williamson Lake for a almost 10 days. I agree the sites are very close together and not very private. The review below didn't like this and moved on. I suspect to Blanket Creek which is a beautiful provincial campsite located on Hwy 23, South of Revelstoke. We have stayed there before and it's great.
But for our purposes Williamson Lake was ideal. We wanted full hookups, which they had and we needed to be close to town. My son was in hockey camp at the arena. It's only about 5 km from downtown Revelstoke which made running back and forth to the arena easy, my wife walked a couple of times.
The campground is great for kids. The lake is a big hit if it's hot out.
There was a bit of mix up over when we leaving. They had us down to leave a day earlier than we planned. Not sure how that happened, my wife checked in and said there was some confusion because if you stay 7 nights you get one night free, so she thinks the free night didn't get marked in. But not sure. We had emailed our stay, but when the discussion came up about the additional day the woman could not check the email. Found that odd. In the end I just paid for another night. So not sure if got a free night or not.
The fees are not bad, but note there is a $2 fee per day for each person over 10. This can add up if you have teenagers. I assumed the fee would include maybe 2 people or small family of 4 or something, that is not the case.
Overall it was a great spot for our purposes and would go back again.
We love Revelstoke so going there is always a pleasurable experience. Revelstoke is big for cyclists. Make sure you bring your road and/or mountain bike if you are into riding. They promote cycling and the info centre has a bike specific brochure with maps of all the road and mountain bike routes in the area. There are two good bike shops in town if you need parts or some repairs.