Safe Underwater Corrosion Condition Assessment of Structures
There have been recent advances in the use of remotely operated vehicles (ROVs), field data
acquisition instrumentation, and photogrammetric analyses for infrastructure condition
assessments. The purpose of this study is to assess the state-of-the-art for underwater
corrosion and coating health assessment techniques. How can these techniques be applied or
tailored to provide new tools for Reclamation to evaluate structure condition in hard to access
areas? Furthermore, how does this new technique compare to inspections currently conducted
by dive teams, both in quality of the inspection and safety? Ideally this mobile inspection unit
could collect data both above and below the waterline.
Need and Benefit
Many Reclamation structures cannot be dewatered, and therefore the extent of corrosion of the
steel and the condition of the protective coating cannot be adequately assessed below the
waterline. Examples include the large spillway gates at Parker Dam (proposal partner John
Steffen, LCDO) and other intake structures or hard-to-access features across Reclamation. Many
of these structures are critical to the integrity of the dams and hydropower plants. Currently,
these structures are either not assessed at all, rely on infrequent and costly dive team
inspections, or they must be shut down and dewatered at a loss of time and money to water
Ideally the technique could also be used for underwater evaluation of non-metallic structural
components. In this way, the inspection would not be limited strictly to metals. For example, an
FY15 Science and Technology project demonstrated an ROV inspection of an intake structure
composed of metal and concrete. This proposal will take these results into consideration when
evaluating potential techniques. Moving these techniques into practice at Reclamation will
improve maintenance planning at reduced cost and reduced risk to employees.
Contact the Principal Investigator for information about partners.
Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Underwater Corrosion Condition Assessment of Hydraulic Steel Structures (final, PDF, 170KB)
By Jessica Torrey
R&D Bulletin completed on September 30, 2019