Osawaike is a lovely place to enjoy some time out from the fast pace of everyday life. See if any water activities are on offer here, or simply enjoy the calming ambiance.
You'll soon discover why this Arashiyama body of water is a hit with travelers. If you're looking for other things to keep you busy, Nijō Castle, Kyoto Imperial Palace, and Kyoto Tower are in this area as well. They won't take you very long to get to from Osawaike.