Risky reservoirs: Maryland counties where aging dams pose the greatest threat

Canva

- Total high-hazard dams: 11
- Number potentially dangerous: 1 (9.1%)
- Potentially dangerous dams include:
--- 1 posing immediate threat

#13. Baltimore County
Canva

- Total high-hazard dams: 10
- Number potentially dangerous: 1 (10.0%)
- Potentially dangerous dams include:
--- 1 in poor condition

#12. Garrett County
Canva

- Total high-hazard dams: 17
- Number potentially dangerous: 2 (11.8%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 1 in poor condition

#11. Montgomery County
Canva

- Total high-hazard dams: 6
- Number potentially dangerous: 1 (16.7%)
- Potentially dangerous dams include:
--- 1 in poor condition

#10. Baltimore city
Canva

- Total high-hazard dams: 4
- Number potentially dangerous: 1 (25.0%)
- Potentially dangerous dams include:
--- 1 posing immediate threat

#9. Harford County
Canva

- Total high-hazard dams: 5
- Number potentially dangerous: 2 (40.0%)
- Potentially dangerous dams include:
--- 2 posing immediate threat

#8. Frederick County
Canva

- Total high-hazard dams: 2
- Number potentially dangerous: 1 (50.0%)
- Potentially dangerous dams include:
--- 1 in poor condition

#7. Cecil County
Canva

- Total high-hazard dams: 6
- Number potentially dangerous: 3 (50.0%)
- Potentially dangerous dams include:
--- 2 posing immediate threat
--- 1 in poor condition

#6. Washington County
Canva

- Total high-hazard dams: 6
- Number potentially dangerous: 3 (50.0%)
- Potentially dangerous dams include:
--- 3 in poor condition

#5. Allegany County
Canva

- Total high-hazard dams: 18
- Number potentially dangerous: 10 (55.6%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 9 in poor condition

#4. Prince George's County
Canva

- Total high-hazard dams: 3
- Number potentially dangerous: 2 (66.7%)
- Potentially dangerous dams include:
--- 2 in poor condition

#3. Wicomico County
Canva

- Total high-hazard dams: 1
- Number potentially dangerous: 1 (100.0%)
- Potentially dangerous dams include:
--- 1 posing immediate threat

#2. Carroll County
Canva

- Total high-hazard dams: 1
- Number potentially dangerous: 1 (100.0%)
- Potentially dangerous dams include:
--- 1 posing immediate threat

This story features data reporting by Paxtyn Merten, writing by Dom DiFurio, and is part of a series utilizing data automation across 50 states.

#1. Charles County
JIM WATSON/AFP via Getty Images