A Visual Assessment of Streambank Stability and Riparian Vegetation: A Watershed Class Project.

Published estimates indicate that 12 million tons of sediment enter the Chesapeake Bay and its tributaries annually.  The sediment originates from urban and residential areas, agricultural fields and shoreline erosion; or from incoming flow from the Atlantic Ocean.  The ongoing sediment loading continues to be a problem for aquatic organisms and submerged aquatic vegetation.  A watershed analysis of sources of sediment is difficult and different sub-watersheds contribute different amounts.  The objective of this project is to describe a protocol for assessing stream bank erosion potential and to relate stream bank condition, riparian zone quality and land use to the potential to contribute sediments to a defined tidal stream hydraulic reach.  This procedure can be used in environmental or watershed courses that focus on water quality.  The location of tidal streams were define with GPS points and were imported to a georeferenced map for future use.  A digital photograph of the stream bank, shoreline and streamside riparian vegetation and an aerial photograph of the land bordering the stream reach were used for the watershed assessment.  The photographs can then be used in a laboratory setting and the percent riparian cover can be determined using a GIS or other methods.  Web-based computer models like LTHIA or GLEAMS-NAPRA can be used to estimate runoff and erosion.  This information can be used in conjunction with the stream bank description to assess the potential for the stream reach to receive sediment from upland areas as well as from the stream bank.  An example data set together with a visual stream assessment for water quality to include riparian zone condition and stream bank stability will be summarized.