Delaware Climate Information Center

High water marks (HWM), typically observed as water stains on buldings, debris lines on the beach, and as storm tides captured from automated sensors, are arguably the best method for capturing the maximum depth and extent of a flood for a large area.

This web site serves as a discovery tool for quickly accessing historically recorded high water marks from significant flooding events within Delaware. It collects, manages, and displays high water marks (HWMs) that are observed throughout Delaware as a result of flooding events. Historical peak water levels can be extracted for past storms or for a selected geographic area.