"Right now we just don't know what we can do that we haven't already done," Lowther said.
During the past 10 days, the river between 17th and 24th streets has been thoroughly searched by kayakers, divers, helicopters and ground crews.
Also, Utah State Parks rangers have checked the Great Salt Lake where the Weber River empties. But officials say the chances of Corbin's body being in the lake are almost impossible. There is a diversion dam at 17th Street, and several canals leading to the Great Salt Lake are protected with screens or flood gates.
Memorial services for Corbin will be held at Lindquist's Layton Mortuary, 1867 N. Fairfield Road, on Saturday at 11 a.m., according to the boy's obituary
Instead of flowers, the family is requesting donations be made to the Red Cross, or to the Weber and Davis County Search and Rescue team, in Corbin's name. As part of the obituary, Corbin's family thanked everyone who volunteered their time to try to find the boy.
The Layton boy fell into the river near 300 W. Exchange Road on April 28 while standing on a boulder so his family could take his picture, police have reported.
Last weekend, the Weber River was temporarily diverted into an adjacent river channel, while water levels simultaneously were lowered by closing the Echo Dam spillway upstream.
Lowther said the diversion was feasible because of the existing secondary river channel near where the boy fell in, and because local companies donated time and machinery to reroute the water.
Had the boy fallen in elsewhere, diverting the river might not have been an option, Lowther said.
"We really wanted to recover this child and let his family have some closure," he said.