The bridge is located on S

The following geomorphic factors were used to determine the best application of streambank protection for the project:

1. The stream width is forty-two feet.

2. The flow is perennial.

Based on the above site conditions, the spurs are designed with sufficient length to protect the toe of slope from the beginning of the bend to the abutment. Following the FHWA document “Stream Stability at Highway Structures,” HEC 20, 2nd edition, the length of the spurs was determined to be 8.5 feet long with varying angles to deflect the thalweg away from the streambank and roadway embankment. Scour at the terminus of the spurs was calculated and additional launching material was provided to protect the base of the spur. The profile of the spur begins behind the top of bank and drops quickly to be six inches above the base flow. The profile deflects the flow away from the streambank, encourages deposition of bed load between the spurs, and protects it from damage caused by floating debris.

3. The bed material is silt loam.

4. The valley setting is low relief valley.

5. There is a wide floodplain.

6. No natural levees.

7. The streambed is incised.

8. The floodplain is alluvial.

9. The stream is highly meandering.

10. The stream is not braided or anabranched.

11. The point bar is narrow and long.

12. Road embankment failure caused by undercutting.

13. Observation of older mappings indicates that the stream is meandering.

14. There is evidence of bed load deposition downstream of the bridge.