Colorado has 1899 dams with recorded construction dates. The oldest dates to 1863 — 163 years ago. Colorado'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 | Hyatt | Jefferson | 1863 | 163 yrs | 24 | High | Unsatisfactory |
| 2 | Waneka | Boulder | 1865 | 161 yrs | 31 | High | Satisfactory |
| 3 | Pleasant Valley | Boulder | 1868 | 158 yrs | 19 | High | Satisfactory |
| 4 | Churches | Jefferson | 1868 | 158 yrs | 9 | Low | Not assessed |
| 5 | Broad | Jefferson | 1870 | 156 yrs | 13 | Low | Satisfactory |
| 6 | Greenview | Pueblo | 1870 | 156 yrs | 8 | Low | Not assessed |
| 7 | Fairview # 1 | Jefferson | 1871 | 155 yrs | 12 | Low | Satisfactory |
| 8 | Bergen East | Jefferson | 1874 | 152 yrs | 40 | High | Satisfactory |
| 9 | Dodd | Boulder | 1875 | 151 yrs | 12 | Low | Satisfactory |
| 10 | Lake Minnequa | Pueblo | 1876 | 150 yrs | 16 | Low | Satisfactory |
| 11 | Mann | Jefferson | 1877 | 149 yrs | 15 | Low | Satisfactory |
| 12 | Lagerman | Boulder | 1878 | 148 yrs | 36 | High | Satisfactory |
| 13 | Baxter | Weld | 1878 | 148 yrs | 8 | Low | Not assessed |
| 14 | Mulligan | Weld | 1878 | 148 yrs | 10 | Low | Fair |
| 15 | Divide | Boulder | 1879 | 147 yrs | 8 | Low | Not assessed |
| 16 | Calkins | Boulder | 1879 | 147 yrs | 8 | Low | Not assessed |
| 17 | Prince No. 1 | Boulder | 1879 | 147 yrs | 14 | Low | Satisfactory |
| 18 | Gold Lake #1 | Boulder | 1879 | 147 yrs | 24 | Significant | Satisfactory |
| 19 | Gold Lake #2 | Boulder | 1879 | 147 yrs | 19 | Significant | Satisfactory |
| 20 | Gold Lake #3 | Boulder | 1879 | 147 yrs | 9 | Significant | Satisfactory |
| 21 | Jones #1 | Grand | 1879 | 147 yrs | 27 | Significant | Satisfactory |
| 22 | Clennon | Weld | 1879 | 147 yrs | 14 | Significant | Satisfactory |
| 23 | Highland #1 | Weld | 1879 | 147 yrs | 17 | Significant | Satisfactory |
| 24 | Marfell Lake No. 1 | Boulder | 1880 | 146 yrs | 12 | Low | Not assessed |
| 25 | Water Supply No 4 | Larimer | 1880 | 146 yrs | 33 | High | Satisfactory |
| 26 | Crystal | Boulder | 1881 | 145 yrs | 11 | Low | Not assessed |
| 27 | Highland #2 (south) | Boulder | 1881 | 145 yrs | 41 | Significant | Satisfactory |
| 28 | Highland #2 (north) | Boulder | 1881 | 145 yrs | 41 | Significant | Satisfactory |
| 29 | Culver | Larimer | 1881 | 145 yrs | 19 | Low | Unsatisfactory |
| 30 | Highland #3 | Weld | 1881 | 145 yrs | 21 | Significant | Satisfactory |
| 31 | Bolts Lake | Eagle | 1882 | 144 yrs | 22 | Low | Fair |
| 32 | La Veta Lake North | Huerfano | 1882 | 144 yrs | 20 | Significant | Fair |
| 33 | Rist Canyon | Larimer | 1882 | 144 yrs | 12 | Low | Not assessed |
| 34 | Warren Lake | Larimer | 1882 | 144 yrs | 23 | High | Satisfactory |
| 35 | Fairport | Larimer | 1882 | 144 yrs | 13 | Significant | Satisfactory |
| 36 | Lone Tree | Larimer | 1882 | 144 yrs | 29 | Significant | Satisfactory |
| 37 | Minnie | Weld | 1882 | 144 yrs | 10 | Low | Not assessed |
| 38 | Logan | Weld | 1882 | 144 yrs | 10 | Low | Not assessed |
| 39 | Hummel | Weld | 1882 | 144 yrs | 15 | Low | Fair |
| 40 | Koenig | Weld | 1882 | 144 yrs | 9 | Low | Not assessed |
| 41 | Donath Lake | Larimer | 1883 | 143 yrs | 26 | Significant | Satisfactory |
| 42 | De France | Weld | 1883 | 143 yrs | 15 | Low | Fair |
| 43 | Buckhorn Lake #2 | Montrose | 1884 | 142 yrs | 30 | Low | Fair |
| 44 | John Townsend | El Paso | 1885 | 141 yrs | 60 | Low | Poor |
| 45 | Mower | Jefferson | 1885 | 141 yrs | 11 | Low | Not assessed |
| 46 | Dixon Canyon | Larimer | 1885 | 141 yrs | 14 | Significant | Satisfactory |
| 47 | Box Elder #2 | Larimer | 1885 | 141 yrs | 13 | Low | Satisfactory |
| 48 | North Poudre #1 | Larimer | 1885 | 141 yrs | 16 | Significant | Satisfactory |
| 49 | Rockwell | Weld | 1885 | 141 yrs | 16 | Low | Fair |
| 50 | Ide and Starbird #2 | Weld | 1885 | 141 yrs | 10 | Low | Not assessed |