What’s a Catch Basin?

November 20, 2020
Posted in News
November 20, 2020 Seventy1 Environmental

 A catch basin is part of a storm drain. Water enters the storm drain through the inlet, falls into a catch basin and passes into the city stormwater system.

Let’s break it down…


There are grate inlets:

And curb inlets:


On the inside of these inlets, under the ground, is a catch basin where water, trash, sediment and debris collect before passing on to the city stormwater system and eventually to our creeks, bays, harbors and ocean.

The catch basins should ideally look like this:

But often they look like this:

Trash, sediment and debris enter the inlet and pass through to the city stormwater system. Overtime, the debris can build up in the catch basin causing odors and backups. Installing filtration inserts on catch basins is a great way to prevent this pollution from reaching our waterways. For unfiltered catch basins, regular cleaning can remove the odors and reduce the chance of flooding.