This drainage feature consists of a deep pit filled with gravel, rubble, or a perforated plastic chamber wrapped in filter fabric. It receives stormwater from roof downspouts or surface drains and acts as a temporary holding tank. The collected water slowly dissipates into the local groundwater table, preventing surface flooding without overloading municipal storm sewers.
Heard on the job
The inspector wants a dry well installed at the bottom of the swale to handle the extra roof runoff.