Estimated long-term aggradation (+) or degradation (-) (ft/m) - Stream Channel.

The estimated long-term change in the elevation of the channel section under the bridge/culvert over the service life of the structure. Enter aggradation values as (+) and degradation values as (-). The primary source of information regarding long-term changes in the stream channel and floodplain is typically the stream morphology report and bridge inspection records. Refer to Chapters 11 and 14 in the Office of Structures H&H Manual for guidance on evaluating aggradation/degradation.