• 6A – Protection & Conservation of Wetlands & Riparian Areas
• 6B – Restoration, Rehabilitation, & Mitigation of Wetlands & Riparian Areas
• 6C – Construction & Maintenance of Vegetated Treatment Systems
• 6D – Education & Outreach for Wetlands, Riparian, & Vegetated Treatment

Wetlands and riparian areas play important roles in filtering out pollutants from runoff, preventing soil erosion, providing flow control, enhancing surface and groundwater storage, providing aquatic and semiaquatic habitat, supporting biological diversity, and providing areas for recreation.

Wetlands are areas that are periodically or permanently inundated or saturated with water and support a prevalence of vegetation typically adapted for life in saturated soils. Wetlands provide many important functions and values, including:

• Protecting water quality by serving as biological filters, absorbing and fixing certain chemical and mineral contaminants that would otherwise flow directly into lakes, rivers, streams, and the ocean.
• Allowing for groundwater recharge.
• Supporting a large diversity of plant and animal species, including some that are found nowhere else except in wetlands.
• Providing habitat for hundreds of species of shore, wading, and migratory birds and for many commercial and non-commercial fish.
• Serving as a water conveyance and holding system, including providing floodwater storage.
• Protecting the shoreline by buffering the coast from waves and storms.
• Providing areas for recreational activities (such as fishing and boating).
• Enhancing viewsheds through contributing to aesthetic values.

Riparian areas are ecosystems bordering a river or stream, where soil moisture is more or less permanently available. Riparian areas are highly productive transitional areas between streams and terrestrial uplands, and support a diverse community of plants and animals. Riparian zones maintain the health and productivity of the stream environment. They reduce the transport of sediment and nitrates from the terrestrial to the aquatic environment, sustain microclimates, and provide large woody debris (which is a source of food and habitat structure).

Changes in hydrology, geochemistry, substrate, or species composition can impair wetland and riparian areas and reduce their ability to filter out pollutants in runoff, which can result in poor water quality in the receiving waters.

Engineered vegetated treatment systems (such as constructed wetlands, vegetated filter strips, buffers, and swales) treat NPS pollution by increasing the interaction time between runoff, soil, and plants. This increases the ability of pollutants in runoff (nutrients, some metals, and some organic molecules) to be attenuated, transformed, absorbed, and volatilized by various processes. Vegetated treatment systems can be placed in upland areas to protect wetlands and other aquatic resources from NPS pollution.

Descriptions of this land use category and its Management Measures are adapted from California’s NPS Encyclopedia. More Info