|Shields Jr, Fletcher|
Submitted to: Management of Landscapes Disturbed by Channel Incision Stabilization Rehabi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/1997
Publication Date: N/A
Interpretive Summary: Streams in many agricultural watersheds are unstable and experience accelerated erosion and sediment deposition. Cost-effective strategies to restore stream channel stability and ecological resources are needed. Previous research has shown that longitudinal stone toe (a ridge of stone) placed along steep, eroding channel banks is one of the most reliable, cost-effective bank stabilization structures available. However, previous work has also shown that aquatic habitats associated with stone toe are generally inferior to that provided by stone spur dikes. This study tested a design that combined attractive features of stone toe and spurs by adding about 16% more stone to existing toe structures. Only modest changes in water depth and width resulted, but overall complexity and diversity improved, and the treated reach provided better habitat than comparison reaches with stone toe but no spurs. This work shows that some potential exists for improving habitat provided by stone toe at minimal incremental cost.
Technical Abstract: Longitudinal stone toe is one of the most reliable and economically attractive approaches for stabilizing eroding banks in incised channels. However, aquatic habitat provided by stone toe is inferior to that provided by spur dikes. In order to test a design that combined features of stone toe and spurs, eleven stone spurs were placed perpendicular to 170 m of the existing stone toe in Goodwin Creek, Mississippi. Physical habitat response was evaluated using two experiments: the treated reach and an adjacent comparison reach were monitored over four years, and the treated reach was compared with seven untreated reaches on a single date three years after construction. Overall results indicated that spur addition resulted in modest increases in baseflow stony bankline, water width, and pool habitat availability, but had only local effects on depth.