Sediment Management


The Los Angeles County Department of Public Works operates year-round to ensure that the flood control system, which includes hundreds of miles of open channels and thousands of miles of storm drains, will be ready for future storms. With, inspection and repair is a multi-year process and once its finished its time to start all over again. In addition to inspections and repairs, there is the day to day maintenance of the facilities which includes tree trimming/removal, right of way clearing, fence repairs and weed abatement to name a few.

One of the major maintenance activities is debris basin clean-outs. These operations require several pieces of heavy equipment and hundreds of man-hours in order to ensure all Public Works' debris basins maintain optimal capacity, thus providing the necessary flood and debris protection to downstream residents.

Debris basin clean-outs generate a tremendous amount of sediment, which must be properly stored. Public Works has developed numerous sediment placement sites (SPSs) throughout the County to address this need. Primarily located adjacent to debris basins, in order to reduce haul distances, these facilities make it possible for Public Works to quickly remove debris from its basins. This is necessary to provide the flood protection to downstream properties in the event of emergency. Over the years, these SPSs have become surrounded by urban. In some cases, homes and businesses surround the SPS, which creates some temporary annoyances for local residents when the SPSs are in operation, such as increased truck traffic, increased dust and noise to name a few. However, these annoyances are necessary to ensure debris basin capacities are maintained.

In addition to Public Works' staff, contract vendors are also utilized to conduct right of way clearing, trash removal, hazardous waste removal, tree trimming, vacuuming and jetting, street sweeping, slope mowing, etc.

All these efforts ensure that when the next storm hits the Southern California Area, Public Works' flood control system will work properly and convey storm waters away from developed areas.