What is the purpose of nonwoven geotextile in inlet protection systems?

The purpose of nonwoven geotextile in inlet protection systems is primarily to filter out sediment. Nonwoven geotextiles are designed to control the movement of water while allowing sediment particles to be captured within the material. This characteristic is essential in managing erosion and sedimentation, particularly near stormwater inlets.

When water flows through a nonwoven geotextile, the fabric's structure enables the passage of water while trapping sediment, which helps prevent larger particles from entering the drainage system. This filtration process is crucial for maintaining water quality and reducing the risk of blockages and flooding that can occur when sediment accumulates in storm drains.

The other options, while related to different functions that materials in erosion control might serve, do not accurately describe the role of nonwoven geotextiles in this context. For instance, holding back large debris or providing structural support is typically associated with other types of materials or systems, while retaining moisture is more relevant to landscape fabrics or agricultural applications rather than sediment control.