A riparian area is the green area immediately adjacent to streams, rivers, and lakes. Riparian areas are identified by the presence of vegetation that requires large amounts of water. The soil in a riparian area consists of layered sediments of varying textures that are subject to intermittent flooding or fluctuating water tables that may reach the soil surface. The duration of soil wetness depends on the water levels of the adjacent water body. This makes a big difference to riparian plants and determines where plants can grow.

Riparian areas serve many important functions, including:

  • ground water recharge,
  • entrapping eroded soil,
  • pollutant trapping and nutrient cycling,
  • reducing soil erosion,
  • increasing stream flows in the summer, and
  • providing food and habitat for fish and other wildlife.

Riparian ecosystems are extremely productive and support most terrestrial wildlife in many arid environments. Because riparian zones occupy low areas in the landscape, ground water is generally nearer to the surface and available for plants.

The fine-textured sediments in floodplains are also able to hold large amounts of water. Water stored in these alluvial soils provides base flow (ground water seepage) to sustain flow in creeks and rivers during dry months.

Riparian vegetation forms a buffer on the edge of a stream that helps slow runoff water velocities, allowing sediment and other pollutants to drop out. Nutrients are taken up by riparian vegetation and later released when vegetation dies or decomposes.

Rooted herbaceous and woody vegetation helps shape aquatic habitat and stabilizes streambanks, retarding erosion.

 

Modified from Living on the Land 2001: Stewardship for Small Acreages
Project Leaders: Susan Donaldson, University of Nevada, Cooperative Extension and Sherman Swanson, University of Nevada, Reno