Netting Systems are large structures placed on primary storm drain lines to capture floatable trash and other debris from a large drainage area. These structures consist of a series of nets that retain all of the floatable trash. During very high storm events the structures are equipped with a bypass to prevent upstream flooding. Routine netting system maintenance ensures that the system is operable year-round.

All City installed Netting Systems meet the Trash TMDL criteria of a "full capture device." *

Due to their cost and potential hydraulic impact on the existing storm drain system; the City has installed a limited number of these systems at strategic locations.

The photo at far left shows the approximately 15-foot long net bags full of trash and debris.

The photo on the right shows the bags after clean out.

* "A full capture system is any single device or series of devices that traps all particles retained by a 5mm mesh screen and has a design treatment capacity of not less than the peak flow rate (Q) resulting from a one-year, one-hour, storm in the subdrainage area. Rational equation is used to compute the peak flow rate: Q=C x I x A, where Q = design flow rate (cubic feet per second, cfs); C = runoff coefficient (dimensionless); I = design rainfall intensity (inches per hour, as determined per the rainfall isohyetal map), and A = subdrainage area (acres)."

The description of this product does not imply endorsement by the City of Los Angeles.