Bank Erosion Hazard Index

BEHI Study

Stream bank erosion is a problem all of our rivers and headwaters face in the Cleveland area. Increasing stormwater flow causes floods, and loss of riparian corridors in an urban setting leave banks vulnerable to high, fast moving water. The resulting erosion widens streams unnaturally and poses a threat to nearby structures like roads and trails. Erosion also causes sedimentation of waterways, which poses significant risk to fish, amphibian, and macroinvertebrate populations.

A method to assess the health of our streams is by using the "Bank Erosion Hazard Index" or BEHI. The BEHI assessment is made up of several metrics that take into account major physical attributes of stream banks. These metrics include:

• Plant root depth: depth relative to bank height
• Root Density: percentage of bank surface covered by roots
• Bank angle
• Surface protection: percentage of bank covered by rocks, logs, etc.
• Bank composition: type of material making up the bank (sand, silt, gravel, etc.)
• Bank stratification: number of distinctive layers of sediment

Each Metric is given a score based on the measured value. Next, each individual metric's score is added together to give an overall score for that bank and then that bank is placed inside a rank category.