CISA cannot demonstrate how its oversight has improved Dams Sector security and resilience because CISA has not coordinated or tracked its Dams Sector activities, updated overarching national critical infrastructure or Dams Sector plans, and collected and evaluated performance information on Dams Sector activities. Furthermore, we found that CISA does not consistently provide information to FEMA to help ensure its assistance addresses the most pressing needs of the Dams Sector. CISA and FEMA also do not coordinate their flood mapping information. Finally, CISA does not effectively use the Homeland Security Information Network Critical Infrastructure Dams Portal to provide external Dams Sector Stakeholders with critical information. We recommended that CISA update the Dams Sector-Specific Plan, its internal organization structures, and establish performance metrics to determine its impact on the Dams Sector. We also recommended it coordinate with FEMA on its grants and flood mapping systems. Finally, we recommended CISA implement a strategy to use the HSIN-CI Dams portal to its fullest potential. We made five recommendations to update CISA’s Sector-Specific Plan, internal organization structures, and coordination with FEMA that, when implemented, will improve dam security and resilience. CISA concurred with all five recommendations.