The objective of Storm Inlet Protection is to install structural Best Management Practices as a barrier to existing stormwater inlet structures. Barriers are provided to promote settling of coarse sediments prior to introduction to storm sewer inlets. Inlet protection measures require frequent inspection and maintenance to ensure capacity.
Filter Sock Inserts
Filter sock inserts refer to pre-fabricated geotextile fabric bags which are inserted into catch basin or law basin inlets to capture and filter coarse sediments to facilitate regular maintenance removal of captured materials following individual storm events.
Sediment Barrier Berms / Check Dams
Berms or check dams (PDF) in the context of inlet protection refer to the installation of temporary barriers installed in conjunction with filter sock inserts to augment the function of the inlet protection measures.
- Berms may consist of rock mulch, fiber rolls, or straw wattles installed along the rear openings of storm inlets to preclude the bypass of sediment laden runoff past filter sock inserts.
- Check dams refer to a rock mulch-filled geotextile tube or equivalent at a sufficient distance upstream from a storm drain inlet to promote a localized backwater effect, such that suspended sediments are deposited prior to the inlet to reduce sediment requiring clean-out within the inlet structure directly.
To mitigate downstream flooding concerns, additional rock check dams may be installed immediately below catch basin or lawn basin inlets to ensure that flows are directed into the formal drainage inlets.