As part of its flood control and water supply responsibilities, the Department of Public Works has 15 major dams and 27 spreading grounds in the county.

Water from the dams is released into flood-control channels and some is diverted into spreading basins where it percolates into the ground and recharges the groundwater.

For 25 years, the County Engineer Department was housed in the historic Higgins Building, a 10-story Beaux-Arts style commercial building that was designed and built by noted architect Arthur L. Haley and engineer Albert Carey Martin in 1910, at the corner of Second and Main Streets in Downtown Los Angeles.

In 1988, the department issued a demolition permit to tear down the historic Golden Gate Theater in East Los Angeles.

Demolition commenced before officials led by then County Supervisor Ed Edelman halted the work with a stop-work order.