Low chord elevation at upstream side of bridge

The average elevation of the low chord (or lowest part of the superstructure) on the upstream side of the bridge. The elevation of the low chord is used by the program to determine whether the bridge will be subject to pressure flow. Please refer to FHWA Manual HEC-18, Fifth Edition, Section 6.10 for a discussion of the procedure for estimating pressure flow.

Click here to see definition sketch of the low chord elevation