Authorities diverted the river's flow into a new channel in the area near 300 W. Exchange Road and divers began searching for the boy about 9:15 a.m.
"We have got the river diverted ... and we are searching," Lowther said.
By 5 p.m., crews were calling it a day, but not without feeling they gave it their all.
"We are disappointed but at peace we did everything we could do," Lowther said, mentioning divers were shoulder-to-shoulder combing the river, but had no luck.
Heavy machinery sent the river back into its regular channel late Saturday afternoon. The search for Corbin will be scaled back, Lowther said. Searchers in kayaks, on foot patrols and using K-9s will continue to look for him.
Typically, drowning victims are found 18 feet from where they fell in, Lowther said, adding that with diversion dams at 17th Street and canals that have screens on them, there is almost no chance the boy's body would have made it to the Great Salt Lake.
Forty divers with the Department of Public Safety and Davis County, and about 60 other search and rescuers with Weber and Davis County, have helped with the search.
The flood gates at Echo Reservoir were closed for a time to lower water levels, and in addition to the water being diverted. Lowther said the company Rain for Rent donated the use of two 22,000-gallon diesel pumps for clearing water from the search area. Crews later brought in a larger third pump to further lower the water level.
Lowther said the diversion did not leave the river channel completely clear: Some areas were shallow enough for wading but some spots were still 10 feet deep.
Corbin fell into the river while standing on a boulder near 300 W. Exchange Road the afternoon of April 28, when his family was taking pictures of him. Family members could not reach him before the waters carried him away. Divers have not been in the river since Tuesday because waters had been too swift and full of debris.
A candlelight vigil for Corbin was scheduled for 7 p.m. Saturday by a bowery west of Kayak Park at Exchange Road and 24th Street, according to a Facebook memorial page set up by the community and friends.