Olympic Canoe / Kayak Slalom Centre

Looking around Athens in GMaps and BEV, with the new BEV stuff around, I spotted a strange water structure. It's very close to the other Olympic constructs, so it could be some sort of event course from that. Or maybe just a park? Or a power plant water release system? If you spin it in BEV, most of the views, the water is turned off. But in GMaps and the West view, the water is running at full. Anyone know what this is?