Several agencies responded to the 16000 block of Dodd Street for reports of a woman who fell off of a party barge, according to Austin-Travis County EMS.
EMS said the call came in at approximately 7 p.m.
EMS officials, Lake Travis firefighters, the Travis County Sheriff's Office and STAR Flight all assisted in the search for the swimmer and at approximately 7:40 p.m. Saturday, officials switched the search from "rescue" to "recovery" mode.
Texas Parks & Wildlife is now leading the investigation.
This is a developing story. Check back for updates.