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

Wendy van Overstreet // Shutterstock

- Total high-hazard dams: 7
- Number potentially dangerous: 2 (28.6%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 1 condition withheld

#50. Athens County
ADC Bradley // Shutterstock

- Total high-hazard dams: 3
- Number potentially dangerous: 1 (33.3%)
- Potentially dangerous dams include:
--- 1 in poor condition

#49. Brown County
Canva

- Total high-hazard dams: 3
- Number potentially dangerous: 1 (33.3%)
- Potentially dangerous dams include:
--- 1 in poor condition

#48. Morrow County
Canva

- Total high-hazard dams: 3
- Number potentially dangerous: 1 (33.3%)
- Potentially dangerous dams include:
--- 1 in poor condition

#47. Adams County
JNix // Shutterstock

- Total high-hazard dams: 8
- Number potentially dangerous: 3 (37.5%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 2 in poor condition

#46. Clinton County
Canva

- Total high-hazard dams: 5
- Number potentially dangerous: 2 (40.0%)
- Potentially dangerous dams include:
--- 2 in poor condition

#45. Pike County
Keith J Finks // Shutterstock

- Total high-hazard dams: 10
- Number potentially dangerous: 4 (40.0%)
- Potentially dangerous dams include:
--- 4 in poor condition

#44. Huron County
JNix // Shutterstock

- Total high-hazard dams: 10
- Number potentially dangerous: 4 (40.0%)
- Potentially dangerous dams include:
--- 4 in poor condition

#43. Perry County
Showcase Imaging // Shutterstock

- Total high-hazard dams: 20
- Number potentially dangerous: 8 (40.0%)
- Potentially dangerous dams include:
--- 6 in poor condition
--- 2 condition withheld

#42. Summit County
Canva

- Total high-hazard dams: 7
- Number potentially dangerous: 3 (42.9%)
- Potentially dangerous dams include:
--- 2 in poor condition
--- 1 condition withheld

#41. Clermont County
Kenneth Sponsler // Shutterstock

- Total high-hazard dams: 14
- Number potentially dangerous: 6 (42.9%)
- Potentially dangerous dams include:
--- 6 in poor condition

#40. Medina County
Susie Prentice // Shutterstock

- Total high-hazard dams: 9
- Number potentially dangerous: 4 (44.4%)
- Potentially dangerous dams include:
--- 4 in poor condition

#39. Geauga County
Mikhalis Makarov // Shutterstock

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

#38. Lake County
Canva

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

#37. Shelby County
CourtneySimons // Shutterstock

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

#36. Mercer County
Canva

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

#35. Monroe County
Donna Wickerham // Shutterstock

- Total high-hazard dams: 4
- Number potentially dangerous: 2 (50.0%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 1 condition withheld

#34. Richland County
Canva

- Total high-hazard dams: 4
- Number potentially dangerous: 2 (50.0%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 1 condition withheld

#33. Guernsey County
JNix // Shutterstock

- Total high-hazard dams: 4
- Number potentially dangerous: 2 (50.0%)
- Potentially dangerous dams include:
--- 2 in poor condition

#32. Gallia County
arthurgphotography // Shutterstock

- Total high-hazard dams: 4
- Number potentially dangerous: 2 (50.0%)
- Potentially dangerous dams include:
--- 2 in poor condition

#31. Hocking County
Canva

- Total high-hazard dams: 7
- Number potentially dangerous: 4 (57.1%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 3 in poor condition

#30. Cuyahoga County
Canva

- Total high-hazard dams: 7
- Number potentially dangerous: 4 (57.1%)
- Potentially dangerous dams include:
--- 3 in poor condition
--- 1 condition withheld

#29. Mahoning County
Canva

- Total high-hazard dams: 7
- Number potentially dangerous: 4 (57.1%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 2 in poor condition
--- 1 condition withheld

#28. Ross County
Canva

- Total high-hazard dams: 5
- Number potentially dangerous: 3 (60.0%)
- Potentially dangerous dams include:
--- 3 in poor condition

#27. Crawford County
Kilmer Media // Shutterstock

- Total high-hazard dams: 10
- Number potentially dangerous: 6 (60.0%)
- Potentially dangerous dams include:
--- 3 in poor condition
--- 3 condition withheld

#26. Warren County
JNix // Shutterstock

- Total high-hazard dams: 8
- Number potentially dangerous: 5 (62.5%)
- Potentially dangerous dams include:
--- 5 in poor condition

#25. Columbiana County
JNix // Shutterstock

- Total high-hazard dams: 11
- Number potentially dangerous: 7 (63.6%)
- Potentially dangerous dams include:
--- 5 in poor condition
--- 1 not rated
--- 1 condition withheld

#24. Belmont County
redtbird02 // Shutterstock

- Total high-hazard dams: 6
- Number potentially dangerous: 4 (66.7%)
- Potentially dangerous dams include:
--- 4 in poor condition

#23. Ashtabula County
BLAZE Pro // Shutterstock

- Total high-hazard dams: 7
- Number potentially dangerous: 5 (71.4%)
- Potentially dangerous dams include:
--- 2 in poor condition
--- 3 condition withheld

#22. Stark County
James Marciniak // Shutterstock

- Total high-hazard dams: 7
- Number potentially dangerous: 5 (71.4%)
- Potentially dangerous dams include:
--- 4 in poor condition
--- 1 condition withheld

#21. Jackson County
Canva

- Total high-hazard dams: 4
- Number potentially dangerous: 3 (75.0%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 2 condition withheld

#20. Wayne County
Madison Muskopf // Shutterstock

- Total high-hazard dams: 4
- Number potentially dangerous: 3 (75.0%)
- Potentially dangerous dams include:
--- 1 not rated
--- 2 condition withheld

#19. Coshocton County
Aiwilliams // Shutterstock

- Total high-hazard dams: 4
- Number potentially dangerous: 3 (75.0%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 2 condition withheld

#18. Carroll County
Canva

- Total high-hazard dams: 8
- Number potentially dangerous: 6 (75.0%)
- Potentially dangerous dams include:
--- 3 in poor condition
--- 3 condition withheld

#17. Muskingum County
Kenneth Keifer // Shutterstock

- Total high-hazard dams: 6
- Number potentially dangerous: 5 (83.3%)
- Potentially dangerous dams include:
--- 4 in poor condition
--- 1 condition withheld

#16. Knox County
Canva

- Total high-hazard dams: 7
- Number potentially dangerous: 6 (85.7%)
- Potentially dangerous dams include:
--- 5 in poor condition
--- 1 condition withheld

#15. Portage County
Canva

- Total high-hazard dams: 8
- Number potentially dangerous: 7 (87.5%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 6 condition withheld

#14. Ashland County
JNix // Shutterstock

- Total high-hazard dams: 10
- Number potentially dangerous: 9 (90.0%)
- Potentially dangerous dams include:
--- 4 in poor condition
--- 1 not rated
--- 4 condition withheld

#13. Harrison County
James W. Thompson // Shutterstock

- Total high-hazard dams: 1
- Number potentially dangerous: 1 (100.0%)
- Potentially dangerous dams include:
--- 1 condition withheld

#12. Marion County
Kenneth Keifer // Shutterstock

- Total high-hazard dams: 1
- Number potentially dangerous: 1 (100.0%)
- Potentially dangerous dams include:
--- 1 in poor condition

#11. Madison County
James Marciniak // Shutterstock

- Total high-hazard dams: 2
- Number potentially dangerous: 2 (100.0%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 1 condition withheld

#10. Clark County
Canva

- Total high-hazard dams: 3
- Number potentially dangerous: 3 (100.0%)
- Potentially dangerous dams include:
--- 3 in poor condition

#9. Miami County
JNix // Shutterstock

- Total high-hazard dams: 3
- Number potentially dangerous: 3 (100.0%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 2 condition withheld

#8. Pickaway County
Canva

- Total high-hazard dams: 3
- Number potentially dangerous: 3 (100.0%)
- Potentially dangerous dams include:
--- 3 in poor condition

#7. Logan County
Canva

- Total high-hazard dams: 3
- Number potentially dangerous: 3 (100.0%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 2 condition withheld

#6. Highland County
The American Explorer // Shutterstock

- Total high-hazard dams: 4
- Number potentially dangerous: 4 (100.0%)
- Potentially dangerous dams include:
--- 2 in poor condition
--- 2 not rated

#5. Lawrence County
Canva

- Total high-hazard dams: 4
- Number potentially dangerous: 4 (100.0%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 1 not rated
--- 2 condition withheld

#4. Meigs County
The American Explorer // Shutterstock

- Total high-hazard dams: 4
- Number potentially dangerous: 4 (100.0%)
- Potentially dangerous dams include:
--- 2 in poor condition
--- 1 not rated
--- 1 condition withheld

#3. Vinton County
Canva

- Total high-hazard dams: 5
- Number potentially dangerous: 5 (100.0%)
- Potentially dangerous dams include:
--- 4 in poor condition
--- 1 condition withheld

#2. Trumbull County
BLAZE Pro // Shutterstock

- Total high-hazard dams: 10
- Number potentially dangerous: 10 (100.0%)
- Potentially dangerous dams include:
--- 1 in poor condition
--- 9 condition withheld

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. Tuscarawas County
Kenneth Bradford // Shutterstock