I don't know if it's been mentioned on any of the forums, but the Topeka Control Line Association is losing a flying field that's been there since the 1940's. It's even a VFW Memorial and a dedicated CL site. There wasn't much warning. A group decided they wanted that corner of the park for a childrens discovery museum, and by the time the club found out, it was pretty much a done deal. After efforts were expended there's been talk of the city putting in a new site, but nothing is concrete.
From watching this field go away, and talking with people in other areas where sites have been lost, it seems like a large part of the flying sites going away can be traced back to a lack of use. It's almost inevitable when fewer people participate all the time. We joined the local R/C club about a year ago so we could fly at their field. There's a posted list at the field with all the club members names. Last year it had twice as many names on it as it does now. Also there are a lot of people we haven't seen flying this year, that were out last year. It's not just CL, it's RC too... It's all shrinking for whatever reasons. The club field here is a really nice place to fly, and I'm a little worried it won't last.