Los Angeles County officials have also entered into 15 contracts worth more than $14 million to patch up damage caused by the Station fire and get ready for winter storms.
County officials will seek federal and state reimbursement for the project, which will also be funded through the Los Angeles County Flood Control District, said Gail Farber, director of the county's Public Works Department.
Debris basins caught more than 1 million cubic yards of debris and mud during the last wave of winter storms, which Antonovich said highlights the need for greater capacity.
"This is enough debris to fill our Rose Bowl," he said.
Enlarging the debris basins will give communities, including La Crescenta and La Cañada Flintridge, better protection from potentially devastating mudflows, he added.
Consistent maintenance of the debris basins helped protect La Cañada residents from greater destruction than that was experienced during February's mudflows, said the city's mayor, Donald Voss.
But the expansion of four debris basins in La Cañada, he said, will improve defenses for residents for the upcoming winter storm season.
In La Crescenta, the project will "ensure that we are all safe and that we could sleep at night," said Cheryl Davis, Crescenta Valley Town Council president.
Expanding the basins will be one thing; finding the room to put the excavated material over the long haul will be another, officials said.
"The total devastation caused by that Station fire has accelerated the need for new placement sites because of the anticipated volume of sediment over the next five to seven years," Antonovich said.
Public Works had a 20-year plan for when sediment placement sites would reach capacity, Farber said. The plan was based on annual maintenance of the debris basins.
But with the Station fire and winter storms, the plan — based on typical annual maintenance — was cut to five years, she said.
Big Briar: From 2,600 cubic yards to 4,800
Mullally: From 9,400 cubic yards to 17,500
Pickens: From 125,000 cubic yards to 156,000
Pinelawn: From 3,200 cubic yards to 4,800
Snover: From 25,000 cubic yards to 37,000
Starfall: From 15,000 cubic yards to 28,300