Iowa Dams
4,124 dams tracked by the National Inventory of Dams
Total Dams
4,124
High Hazard
91
2.2%
Poor / Unsatisfactory
25
Average Age
46 yrs
Hazard Classification
High91 (2.2%)
Significant274 (6.6%)
Low3,759 (91.1%)
Condition Assessment
Satisfactory259 (6.3%)
Fair81 (2.0%)
Poor / Unsatisfactory25 (0.6%)
Not Rated3,759 (91.1%)
Federal
25
State
141
Local
1,938
Private
2,014
Tallest Dams
- Coralville Dam132 ft
- Saylorville Dam125 ft
- County Basin Dam104 ft
- Rathbun Dam100 ft
- Brushy Creek Dam100 ft
High Hazard Dams
- Coralville DamHigh
- Saylorville DamHigh
- Rathbun DamHigh
- Brushy Creek DamHigh
- Big Creek Barrier DamHigh
Poor Condition Dams
All Dams in Iowa
Showing 1926–1950 of 3,759
| Dam Name | Height (ft) | Year | Hazard | Condition |
|---|---|---|---|---|
| Marshall Dam Montgomery County | 33 | 1989 | Low | Not Rated |
| Marsh Dam Taylor County | 30 | 1990 | Low | Not Rated |
| Martin Dam Dallas County | 27 | 1964 | Low | Not Rated |
| Martins Dam Crawford County | 23 | 1966 | Low | Not Rated |
| Marywood Farms Dam Warren County | 35 | 1966 | Low | Not Rated |
| Marywood Farms Wetland Dam Warren County | 12 | 2007 | Low | Not Rated |
| Marywood Farms Wetland Dam #2 Warren County | 8 | 2007 | Low | Not Rated |
| Masek Dam Winneshiek County | 25 | 2001 | Low | Not Rated |
| Mason1 Dam Madison County | 24 | 2004 | Low | Not Rated |
| Mason City-Lehigh Cement Milldam Cerro Gordo County | 8 | 1924 | Low | Not Rated |
| Mason Dam Jasper County | 22 | 1963 | Low | Not Rated |
| Mass Dam Mills County | 28 | 1959 | Low | Not Rated |
| Massey Dam Decatur County | 28 | 1986 | Low | Not Rated |
| Massner Dam Louisa County | 27 | 1977 | Low | Not Rated |
| Masters Dam Lucas County | 30 | 1984 | Low | Not Rated |
| Mather Dam Page County | 33 | 2012 | Low | Not Rated |
| Mathes Des Moines County | 64 | 1941 | Low | Poor |
| Matt Brown Dam Union County | 32 | 2019 | Low | Not Rated |
| Matthew Brown Union County | 30 | 2018 | Low | Not Rated |
| Matt Leichty Dam Henry County | 29 | 2008 | Low | Not Rated |
| Maudsley Dam Kossuth County | 37 | 1983 | Low | Not Rated |
| Maurer Dam O'Brien County | 43 | 2000 | Low | Not Rated |
| Maxon Reservoir Dam Monroe County | 34 | 1984 | Low | Not Rated |
| Maxwell Dam Henry County | 21 | 2008 | Low | Not Rated |
| Maxwell Dam Woodbury County | 38 | 1960 | Low | Not Rated |
Data sourced from the National Inventory of Dams (NID). Hazard classification reflects potential consequences of failure, not the likelihood of failure.