Oldest Dams in Iowa
Iowa has 4098 dams with recorded construction dates. The oldest dates to 1857 — 169 years ago. Iowa's earliest dams were built in the 19th century, an era of westward expansion, irrigation development, and early water infrastructure. Older dams require particular attention for safety, as many were built before modern engineering standards.
| # | Dam | County | Year Built | Age | Height (ft) | Hazard | Condition |
|---|---|---|---|---|---|---|---|
| 1 | Vernon Spring Dam | Howard | 1857 | 169 yrs | 8 | Low | Not Rated |
| 2 | Lidtke Mill Dam | Howard | 1860 | 166 yrs | 12 | Low | Not Rated |
| 3 | Waverly Milldam | Bremer | 1872 | 154 yrs | 12 | Low | Satisfactory |
| 4 | Fairbank Dam | Buchanan | 1880 | 146 yrs | 12 | Low | Not Rated |
| 5 | Coralville Milldam | Johnson | 1880 | 146 yrs | 13 | Low | Not Rated |
| 6 | Fairfield Water Works Dam No 1 | Jefferson | 1888 | 138 yrs | 40 | Significant | Satisfactory |
| 7 | Nora Springs Low Head Dam | Floyd | 1895 | 131 yrs | 12 | Low | Not Rated |
| 8 | Grade Lake Dam | Clarke | 1900 | 126 yrs | 44 | High | Satisfactory |
| 9 | Q Pond Park Dam | Clarke | 1900 | 126 yrs | 34 | Low | Not Rated |
| 10 | Crystal Lake Dam | Clinton | 1900 | 126 yrs | 24 | Low | Not Rated |
| 11 | Fairfield Waterworks Dam No 2 | Jefferson | 1900 | 126 yrs | 33 | Low | Satisfactory |
| 12 | Walton Lake Dam | Jefferson | 1900 | 126 yrs | 35 | Significant | Satisfactory |
| 13 | Strunk Dam | Lee | 1900 | 126 yrs | 41 | Low | Not Rated |
| 14 | Lineville Reservoir Dam | Wayne | 1900 | 126 yrs | 21 | Low | Not Rated |
| 15 | Promise City Reservoir Dam | Wayne | 1900 | 126 yrs | 25 | Low | Not Rated |
| 16 | Bobwhite Lake Dam | Wayne | 1900 | 126 yrs | 27 | Significant | Fair |
| 17 | Otranto Dam | Mitchell | 1902 | 124 yrs | 7 | Low | Not Rated |
| 18 | Manchester Milldam | Delaware | 1905 | 121 yrs | 11 | Low | Not Rated |
| 19 | Burlington Street Dam | Johnson | 1906 | 120 yrs | 20 | Low | Not Rated |
| 20 | Lake Oelwein Dam | Fayette | 1908 | 118 yrs | 16 | Low | Not Rated |
| 21 | Seymour Reservoir Dam | Wayne | 1908 | 118 yrs | 24 | Low | Fair |
| 22 | Anamosa | Jones | 1909 | 117 yrs | 12 | Low | Satisfactory |
| 23 | Oakland Mills Dam | Henry | 1910 | 116 yrs | 10 | Low | Satisfactory |
| 24 | New London Country Club Dam | Henry | 1910 | 116 yrs | 26 | Low | Satisfactory |
| 25 | Fraser Milldam | Boone | 1911 | 115 yrs | 7 | Low | Not Rated |
| 26 | Decorah Upper Milldam | Winneshiek | 1911 | 115 yrs | 8 | Low | Not Rated |
| 27 | Upper Centerville Reservoir Dam | Appanoose | 1912 | 114 yrs | 48 | Significant | Fair |
| 28 | Lower Centerville Reservoir Dam | Appanoose | 1912 | 114 yrs | 39 | Significant | Fair |
| 29 | Humboldt Milldam | Humboldt | 1912 | 114 yrs | 13 | Low | Not Rated |
| 30 | East Lenox Reservoir Dam | Adams | 1913 | 113 yrs | 25 | Significant | Satisfactory |
| 31 | Redfield Dam | Dallas | 1913 | 113 yrs | 9 | Low | Not Rated |
| 32 | Marble Rock Milldam | Floyd | 1913 | 113 yrs | 15 | Low | Not Rated |
| 33 | West Lenox Reservoir Dam | Taylor | 1913 | 113 yrs | 25 | Significant | Not Rated |
| 34 | Waucoma Milldam | Fayette | 1914 | 112 yrs | 11 | Low | Not Rated |
| 35 | Monticello Milldam | Jones | 1914 | 112 yrs | 12 | Low | Not Rated |
| 36 | Fort Atkinson Milldam | Winneshiek | 1914 | 112 yrs | 11 | Low | Not Rated |
| 37 | Waterloo Milldam | Black Hawk | 1915 | 111 yrs | 7 | Low | Satisfactory |
| 38 | East Lake Dam | Clarke | 1915 | 111 yrs | 41 | Significant | Satisfactory |
| 39 | Williamson Pond Dam | Lucas | 1915 | 111 yrs | 32 | Low | Not Rated |
| 40 | Crystal Lake Dam | Lucas | 1915 | 111 yrs | 27 | Significant | Fair |
| 41 | Des Moines-center Street Milldam | Polk | 1916 | 110 yrs | 11 | Low | Not Rated |
| 42 | Black Hawk Lake Dam | Sac | 1916 | 110 yrs | 12 | Significant | Satisfactory |
| 43 | Humeston Reservoir Dam | Wayne | 1916 | 110 yrs | 31 | Significant | Poor |
| 44 | Corning Reservoir Dam | Adams | 1917 | 109 yrs | 30 | Significant | Satisfactory |
| 45 | Nashua Milldam | Chickasaw | 1917 | 109 yrs | 20 | Significant | Fair |
| 46 | Lynnville Dam | Jasper | 1918 | 108 yrs | 12 | Low | Not Rated |
| 47 | St Ansgar Milldam | Mitchell | 1919 | 107 yrs | 9 | Low | Not Rated |
| 48 | Homepond Dam | Decatur | 1920 | 106 yrs | 30 | Significant | Fair |
| 49 | Des Moines-scott Street Milldam | Polk | 1920 | 106 yrs | 7 | Low | Not Rated |
| 50 | Old Reservoir Dam | Ringgold | 1920 | 106 yrs | 25 | Low | Not Rated |