Map of All 425 Maryland Dams
Maryland has 425 dams in the National Inventory of Dams — and 107 are classified as high hazard (25% of the state’s total), meaning failure would likely cause loss of life. 33 Maryland dams are both high-hazard and in poor or unsatisfactory condition.
Use the interactive Maryland dams map below to explore every dam in the state, color-coded by hazard level. Click any dam for its condition assessment, last inspection date, and Emergency Action Plan status. Or view the full US Dams interactive map to compare Maryland to every other state.
Hazard
Condition
Purpose
Maryland Dams by the Numbers
- 425 total dams in Maryland
- 107 high hazard — failure would likely cause loss of life
- 136 significant hazard
- 181 low hazard
- 92 in poor or unsatisfactory condition (71 poor, 21 unsatisfactory)
- 33 Maryland dams are both high-hazard AND in poor/unsatisfactory condition
Data source: US Army Corps of Engineers, National Inventory of Dams (NID).
The Tallest Dams in Maryland
The tallest dam in Maryland is Jennings Randolph Dam at 296 feet, completed in 1981. The 10 tallest Maryland dams from the National Inventory of Dams:
| Dam | Height | Year | Primary Purpose | Condition | County |
|---|---|---|---|---|---|
| Jennings Randolph Dam | 296 ft | 1981 | Flood Risk Reduction | Not Available | Garrett |
| Savage River Dam | 184 ft | 1952 | Flood Risk Reduction | Satisfactory | Garrett |
| Liberty Dam | 175 ft | 1953 | Water Supply | Unsatisfactory | Baltimore |
| Prettyboy Dam | 155 ft | 1936 | Water Supply | Fair | Baltimore |
| T. Howard Duckett Dam | 139 ft | 1953 | Water Supply | Fair | Howard |
| Loch Raven Dam | 130 ft | 1923 | Water Supply | Satisfactory | Baltimore |
| Druid Hill Lake Reservoir and Storage Tanks | 118 ft | 1871 | Water Supply | Poor | Baltimore City |
| Little Seneca Dam | 99 ft | 1984 | Water Supply | Fair | Montgomery |
| Rocky Gap Dam | 98 ft | 1969 | Water Supply | Poor | Allegany |
| Conowingo | 94 ft | 1928 | Hydroelectric | Satisfactory | Cecil |
High-Hazard Maryland Dams in Poor Condition
The most concerning dams are those classified as high-hazard that also carry a Poor or Unsatisfactory condition rating — 33 dams in Maryland. Notable examples:
- Liberty Dam (175 ft, Baltimore County) — Water Supply, Unsatisfactory condition
- Druid Hill Lake Reservoir and Storage Tanks (118 ft, Baltimore City County) — Water Supply, Poor condition
- Rocky Gap Dam (98 ft, Allegany County) — Water Supply, Poor condition
- Piney Run Dam (73 ft, Carroll County) — Water Supply, Unsatisfactory condition
- Warner Gap Hollow Dam (65 ft, Washington County) — Water Supply, Unsatisfactory condition
Filter the interactive US Dams map by hazard and condition to see all of them on one view.
Dam Safety in Maryland
Dam safety in Maryland is overseen by the state dam safety program, in coordination with federal regulators: the US Army Corps of Engineers, the Bureau of Reclamation (for federal water projects), the Tennessee Valley Authority where applicable, and the Federal Energy Regulatory Commission (FERC) for licensed hydropower dams. Emergency Action Plans are typically required for high-hazard dams under state regulations.
Frequently Asked Questions
How many dams are in Maryland?
Maryland has 425 dams in the National Inventory of Dams tracked by the US Army Corps of Engineers: 107 high hazard, 136 significant hazard, and 181 low hazard.
What is the tallest dam in Maryland?
The tallest dam in Maryland is Jennings Randolph Dam at 296 feet, completed in 1981. It is primarily a flood risk reduction structure.
How many Maryland dams are in poor condition?
92 Maryland dams are currently rated as being in Poor or Unsatisfactory condition. Of those, 33 are also classified as high-hazard — meaning failure would likely cause loss of life.
