Here's a photo from the Commercial Appeal archive. Barney Sellers took this shot of the cleaning out of Rainbow Lake in 1981, back when they list the draining and cleaning as an annual event. Now that more fish live in the lake, I'm sure that those of us who spent two days catching fish would be happy if the plumbing doesn't need attention as often as every year. Chris Baker, one of the lead Zoo guys on the project, is personally hoping for once a decade instead.