sideinlet

A side inlet is a drainage structure designed to intercept surface runoff from the side of a roadway, shoulder, or embankment and convey it into a storm sewer or open channel. It is typically located at the edge of pavement and may be flush with the surface or set behind a curb, depending on local design practices.

Placement and function: Side inlets are positioned to collect water that flows along the pavement edge during rainfall or snowmelt. They connect to a storm drainage system, such as a storm sewer, open ditch, or culvert, and help prevent ponding and local flooding by rapidly removing water from the roadway or shoulder.

Construction and components: A side inlet generally consists of an opening protected by a grate or slot, housed in a concrete or metal frame. Inside, it may include a short inlet trough or throat and a connection to a conduit or pipe. Grates are designed to balance safety (minimizing debris entry) with hydraulic capacity.

Types: Common variants include curb-opening inlets, which occupy the curb line; slot inlets, which use a narrow slot opening; and combination or driveway side inlets, which blend curb and grate features to accommodate vehicle access and debris control.

Design and maintenance considerations: Design focuses on hydraulic capacity for peak runoff, debris filtration, structural durability, and ease of cleaning. Regular maintenance includes removing trash and sediment, inspecting for damage, and ensuring that the grate remains unobstructed for safety and performance.

See also: curb inlet, catch basin, storm drain, grate inlet, infiltration structure.