What is the main purpose of a sediment basin?

The primary function of a sediment basin is to allow sediment to settle out of the water before it leaves the site. These basins are designed to slow down the water flow, which helps facilitate the sedimentation process. When surface runoff enters a sediment basin, the decrease in velocity allows suspended particles to settle to the bottom due to gravity. This is crucial for erosion control and maintaining water quality, as it helps prevent sediment-laden water from entering nearby water bodies, which can cause ecological damage and degradation of water quality.

While filtering pollutants may occur as a secondary benefit when sediment settles, the main and most critical purpose remains the removal of sediment from the water column. Hence, sediment basins are an essential component in stormwater management practices.