Since the 1990s, NHC has evaluated over 1,000 bridges to determine their vulnerability to scour and erosion damage. These studies have been for clients at the federal, state, provincial, county, and municipal levels. Evaluations follow guidelines in the Transportation Association of Canada (TAC) Guide to Bridge Hydraulics, to which NHC experts contributed, and Federal Highway Administration (FHWA) Hydraulic Engineering Circulars (HECs) that address scour at bridges (HEC-18) and stream stability at highway structures (HEC-20). We also apply supplemental procedures and field inspection to complement FHWA and TAC guidance. We evaluate bridges at the reach and local scale for lateral stability of the river channel, longitudinal profile aggradation or degradation, contraction and local scour, and adequacy of scour countermeasure protection. We also consider watershed influences and climate change. Evaluations meet the requirements of the Bridge Scour Evaluation Program in British Columbia and FHWA National Bridge Inspection Standards (NBIS) in the US.