What is the function of a rain garden?

A rain garden is designed primarily to capture and treat stormwater runoff through natural filtration. This is important because stormwater can carry pollutants and sediments from paved surfaces like roads and parking lots into nearby waterways, negatively impacting water quality and local ecosystems.

Rain gardens use a variety of native plants and soil amendments that allow water to infiltrate the ground, trapping pollutants and filtering the stormwater naturally. The design of a rain garden typically includes a depression that holds water temporarily, allowing it to percolate into the ground instead of flowing directly into storm drains or rivers, thereby reducing runoff and promoting groundwater recharge.

While the other options touch on different aspects of landscaping or event hosting, they do not capture the primary ecological function of a rain garden, which is centered around improving water quality and managing stormwater.