Extreme Coastal Water Levels with Annual Exceedance Probabilities

Extreme Water Levels from CO-OPS provides annual exceedance probability levels for coastal water level stations. The dataset is produced by the National Oceanic and Atmospheric Administration's Center for Operational Oceanographic Products and Services using stations with at least 30 years of historical data. It was last updated in March 2026.

Use Cases

• Coastal hazard assessment based on statistical probabilities of extreme water levels.
• Navigational safety planning based on the likelihood of rare high or low water events.
• Ecosystem management informed by historical extreme water level frequencies.
• Evaluating current water conditions against historical extremes to identify rare events.
• Local planning for flood risk using 1% annual exceedance probability levels.

Strengths

• Data is derived from stations with at least 30 years of historical records, providing a long-term basis for analysis.
• Statistical analysis focuses on extreme high and low water levels, which are critical for hazard assessment.
• Produced by the authoritative Center for Operational Oceanographic Products and Services (CO-OPS).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• The analysis excludes tsunami peak levels due to their infrequency in the historic record.

Provenance

Source

National Oceanic and Atmospheric Administration, Department of Commerce

Collection Method

Statistical analysis of historical extremely high and low water levels from CO-OPS tide gauge stations.

Freshness

Last updated 2026-03-10 19:31:46.817764; freshness should be verified.

Geography

Coastal United States and territories, including locations in the Atlantic Ocean, Pacific Ocean, Caribbean Sea, and American Samoa.