Stream Stability Assessment Techniques

Streams and rivers are dynamic systems which are undergoing constant change. In most cases these changes are gradual; however, the changes can be accelerated by development in the watershed. The increases in rate and duration of runoff which accompanies urbanization has resulted in the rapid destabilization of countless miles of streams. The resulting bank erosion, bed degradation and bed aggradation has threatened infrastructure that is immediate to the stream and has adversely impacted water quality and the environment. The Baltimore District of the U.S. Army Corps of Engineers has been involved in several river and stream restoration studies in the mid Atlantic area. The initial phase of these studies involve a rapid assessment of areas within the watershed to determine target areas for work. A combination of biologic and engineering field investigation, GIS analysis, and hydrologic analysis has been used in this assessment and analysis. The analysis is conducted by a multidiciplined team with diverse expertise in areas such as biology, ecology, hydrology, hydraulics/geomorphology, and real estate. A visual hydraulic assessment is made sufficient to qualitatively categorize the bed and bank stability as well as the bank erosion potential. The current paper will primarily focus on the hydraulic engineering environmental channel stability field assessment of existing conditions that was developed for use in these studies.