PROJECT LEADER:
John C. Hayes
COOPERATOR:
Mark Corley, South Carolina Department of Natural Resources, Columbia, South Carolina
FUNDING AGENCIES:
South Carolina Agricultural Experiment Station
South Carolina Department of Health and Environmental Control (DHEC)
U. S. Environmental Protection Agency
DESCRIPTION
A project designed to demonstrate proper use of both natural and constructed riparian zones to remove sediment was initiated in the coastal plains of South Carolina. Vegetation downstream of a simulated disturbed area was instrumented to measure inflow and outflow from the riparian zone.
The studies showed that if buffer zones are at least 30 feet in width, much of the sediment, nutrients and other pollutants in runoff, can be removed prior to entering water bodies. Runoff into and out of riparian zones was monitored for flowrate and sediment concentration. This information was used to estimate efficiencies in the riparian zones.
To evaluate the effectiveness of this practice, if it is adopted on a large scale, a hypothetical situation was developed relating vegetative filter size with source area. USDA has funded vegetative filter strips in numerous locations in the past through cost sharing. Many have not proven effective. The intent of this work was to demonstrate where and how constructed riparian filter strips should be installed and compare this with naturally occurring riparian zones. In addition, the work had particular relevance to developing and urban areas that may present water quality problems of a different type because of oils, greases, heavy metals, or other substances that generally are not present in agricultural runoff.
SIGNIFICANCE
Riparian vegetation is vegetation located adjacent to the bank of a natural water-course. Riparian vegetative filter strips include areas that are located near, but not necessarily adjacent to, streams. Riparian vegetation is sometimes considered to be only natural vegetation, whereas others consider it to include any vegetation located immediately adjacent to streams, rivers, or other waterbodies. The vegetation provides removal of sediment, organic material, nutrients and other chemicals from flowing water. Riparian zones function through a combination of deposition, infiltration, plant uptake, absorption and volatilization in order to reduce movement of pollutants into waterbodies.