Catch Basin

A catch basin is a type of storm drainage system used to collect rainwater and other debris. The idea of a catch basin can be traced back to ancient times, when early civilizations dealt with seasonal flooding by digging irrigation canals and building catch basins to ensure crops had enough water for the remainder of the year. Today, however, much of our urban land as we know it is covered with buildings, concrete and asphalt parking lots and streets. Therefore, when it rains, water no longer can soak into the ground. If there were no means of removing water from all those hard surfaces, we would have one big lake, so catch basins were invented by engineers for modern day management of storm drainage run-off.

Catch basins come in many types, sizes, dimension and are built with many different materials.Two main types of catch basins are drop inlets and curb opening (or curb inlet) catch basins.


Drop inlet catch basins are designed to be installed at all the low spots of an area so that the water will flow to the drop inlet and then will continue to drop through the grated inlet. Many drop inlets are usually connected with a concrete valley gutter (a.k.a. "v-gutter"). Parking lots often use drop inlets made with concrete and a steel frame and grate on top.

Curb inlet catch basins are another type of catch basin and used often on the city streets. This catch basin is located usually along the sidewalk, adjacent to a curb and gutter. Improved streets are designed to have the rain flow off the street into a gutter. Then, rain water will follow the gutter's fall toward an opening in the curb that is the curb opening.

Curb opening catch basins are built with steel rebar and concrete and are typically poured in place. Each catch basin usually has a manhole ring and cover built into the deck to provide access to maintenance personnel. A protection bar (a.k.a. "pro bar") is placed in front of the opening to prevent children and large debris from gaining access into the catch basin.

From these catch basins, rain water travels through many types of drainage systems including a series of connected pipelines, channels, dams, rivers, retention and detention drain systems. Most rain water ends up in the ocean. For this reason, it is important that all catch basins be maintained and kept clean regularly to prevent large debris from building up and clogging the storm drainage system. A poorly kept drainage system may cause flooding, which in turn can also cause structural damage to adjacent buildings and other structures. Catch basins serve to mitigate floods, especially during the rainy season, recognized in the pipeline construction industry between months October through April.