32Total Dams
5High Hazard
6Significant
Dam Safety in Johnson County, Iowa
Johnson County has 32 dams tracked in the National Inventory of Dams. Of these, 5 are classified as high hazard — meaning failure would probably cause loss of human life. Another 6 carry a significant hazard classification. Currently, 1 dam has a condition assessment of poor or unsatisfactory.
The average dam in Johnson County is 49 years old. The most common purpose is fire protection, stock, or small fish pond. The tallest dam is Lake Macbride Dam at 56 ft.
Explore more: Oldest dams in Iowa · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| North Branch Ralston Creek Dam | High | Satisfactory | 37 | Flood Risk Reduction | 1983 |
| Oaknoll Dam | High | Fair | 25 | Fire Protection, Stock, Or Small Fish Pond | 1994 |
| West Branch Flood Control Dam | High | Satisfactory | 24 | Flood Risk Reduction | 2012 |
| Coralville Regional Detention Basin | High | Satisfactory | 23 | Flood Risk Reduction | 2001 |
| Scott Blvd Dam | High | Satisfactory | 20 | Flood Risk Reduction | 1980 |
| Lake Macbride Dam | Significant | Satisfactory | 56 | Recreation | 1930 |
| Twin Valley Lakes - East Dam | Significant | Poor | 50 | 1965 | |
| Brown Deer Golf Course Dam | Significant | Satisfactory | 46 | Recreation | 1970 |
| Dovetail Estates Dam | Significant | Not assessed | 23 | Other | 1999 |
| Progress Park Dam | Significant | Satisfactory | 23 | Flood Risk Reduction | 2005 |
| Rolling Hills Dam | Significant | Not assessed | 20 | Recreation | 2002 |
| Oakridge Lake Estates Dam | Low | Not assessed | 42 | Recreation | 1977 |
| Dunham Dam | Low | Not assessed | 38 | Fire Protection, Stock, Or Small Fish Pond | 1978 |
| Petchulat Dam | Low | Not assessed | 36 | Fire Protection, Stock, Or Small Fish Pond | 1993 |
| F.w.kent Park Dam | Low | Not assessed | 34 | Recreation | 1972 |
| Randall Dam | Low | Not assessed | 31 | Fire Protection, Stock, Or Small Fish Pond | 1976 |
| Arp Dam | Low | Not assessed | 31 | Fire Protection, Stock, Or Small Fish Pond | 1970 |
| Iowa Noname97 | Low | Not assessed | 31 | Debris Control | 1991 |
| Leonard Dam | Low | Not assessed | 30 | Fire Protection, Stock, Or Small Fish Pond | 2001 |
| Marak Dam | Low | Not assessed | 30 | Fire Protection, Stock, Or Small Fish Pond | 1970 |
| Miller Dam | Low | Not assessed | 29 | Fire Protection, Stock, Or Small Fish Pond | 1971 |
| Valley View Heights Dam | Low | Not assessed | 29 | Recreation | 1976 |
| Plotz Dam | Low | Not assessed | 28 | Recreation | 1968 |
| Kent Park 1 East Dam | Low | Not assessed | 28 | Grade Stabilization | 1997 |
| Carson Dam | Low | Not assessed | 27 | Fire Protection, Stock, Or Small Fish Pond | 1978 |
| Zenishek Dam | Low | Not assessed | 25 | Fire Protection, Stock, Or Small Fish Pond | 1979 |
| Stoppelmoor Dam | Low | Not assessed | 24 | Fire Protection, Stock, Or Small Fish Pond | 1974 |
| Hays Dam | Low | Not assessed | 22 | Fire Protection, Stock, Or Small Fish Pond | 2002 |
| Bourjaily Dam | Low | Not assessed | 22 | Fire Protection, Stock, Or Small Fish Pond | 1971 |
| Burlington Street Dam | Low | Not assessed | 20 | Other | 1906 |
| North Ridge Park Dam | Low | Not assessed | 20 | Recreation | 1993 |
| Coralville Milldam | Low | Not assessed | 13 | Recreation | 1880 |