Follow CBSDFW.COM: Facebook | Twitter

RIVER OAKS (CBSDFW.COM) – For the third straight day, rescuers are heading out to the Trinity River to search for a missing kayaker. But over the last two days, swift water has made efforts difficult.

READ MORE: Appeals Court Ruling Keeps Abortion Ban In Place In Texas

Edgar Castro was out with friends when his kayak tipped over in rushing water, over a low crossing on Saturday. Castro’s friend was able to swim to shore, but he was not.

Rescue crews will be focusing on an area around River Oaks Boulevard and Sam Calloway Road. But it’s debris being moved by the swift water in the Trinity that is a concern.

READ MORE: Amtrak Train From Fort Worth Crashes In Oklahoma, Four Hurt

Workers with Texas Parks and Wildlife even brought in a specially equipped boat, with side-scan sonar.

Recent rains have raised the water level of the river significantly. At one point, the water flow just downstream from where Castro went missing was measured at nearly 3500 cubic feet a second – that’s enough to fill an Olympic-sized swimming pool in half a minute.

It’s not clear if Castro was wearing a life jacket.

MORE NEWS: Critical Race Theory Law Could Be Behind Latest Southlake Racism Controversy

(©2015 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)