Victim-kayaker was one of three who placed their kayaks into the water just below the spillway. Two of the victim-kayaker friends went ahead downstream in the fast current. The victim-operator got too close to the dam and got swamped & capsized from waves & current generated by the dam spillway. His kayak did not have a skirt so the kayak filled quickly with water & got caught in the circular flow of the water below the dam. Kayaker called to a fisherman on shore to call 911. Which the fisherman did. While caught in the circular current, the kayak & operator would find themselves directly under the waterfall of the open gate forcing the kayaker to go under water. Rescue personnel arrived & attempted to throw the kayaker ropes. This effort failed. After 45 minutes in the water, kayaker climbed onto a concrete shelf behind the waterfall. Rescue personnel were then able to assist the kayaker into a rescue boat & transport him to ambulance staff located down river at the hwy 53 bridge. From there he was transported to the mayo luther hospital in eau claire for treatment of hypothermia. Kayaker-victim was released from hospital later same day at 6:30pm. Kayak was yet to be recovered at time of report.