Not sure about pools in Columbia, but my parents have a house on Lake Murray. There are several areas around the lake that are open seasonally for swimming. I think the largest of these is also right at the dam on the Lexington side. Also, there is a triathlon in Lake Murray
www.Set-upinc.com. The race director for this (Leslie Pujoul Brown) is probably a good source of info on training locations. Last year she mentioned that they did a training swim the length of the dam. You can find her contact info at
www.bayislandstriathlon.com.
Tim Anderson
"It's the nature of the internets that you get some dweeb who knows nothing about (insert topic here) pontificates about (topic), believing that his/her opinion is worth the same as opinions from those who actually knows what's going on." --Echappist