What is the primary function of a wet swale in stormwater management?

The primary function of a wet swale in stormwater management is to reduce stormwater volume by allowing runoff to infiltrate into the soil while also treating the stormwater as it moves through the swale. Wet swales are designed to handle larger volumes of water and help to manage the flow of stormwater coming from upstream best management practices (BMPs). As water travels through the vegetation and soil found in the swale, pollutants are filtered out, and the water may be temporarily stored, leading to decreased peak flows and volumes that could otherwise cause flooding, erosion, or downstream water quality issues.

Although wet swales can contribute to aesthetic improvements and potentially serve recreational purposes or support local biodiversity, these functions are secondary compared to their core role in stormwater volume reduction and management. The design and function of wet swales are primarily focused on improving water quality and managing flow, making them a critical component in an effective stormwater management system.