Dams by State
Dam inventory data broken down by U.S. state, from 92,625 dams in the National Inventory of Dams.
Dam counts vary significantly by state, driven by geography, agricultural irrigation needs, water storage requirements, and hydroelectric development. States with mountainous terrain and extensive river systems — such as Texas, Kansas, and Missouri — tend to have large dam inventories. The hazard potential classification reflects the potential consequences of dam failure, not the likelihood of failure itself. High-hazard dams are those where failure would likely cause loss of human life.
Dams by State
All U.S. states with dams in the National Inventory of Dams, sorted by total count.
| # | State | Total Dams | High Hazard | Browse |
|---|---|---|---|---|
| 1 | TEXAS (TEXAS) | 7,402 | 1,607 | Browse |
| 2 | KANSAS (KANSAS) | 6,490 | 328 | Browse |
| 3 | MISSISSIPPI (MISSISSIPPI) | 6,092 | 349 | Browse |
| 4 | GEORGIA (GEORGIA) | 5,412 | 541 | Browse |
| 5 | MISSOURI (MISSOURI) | 5,385 | 1,478 | Browse |
| 6 | OKLAHOMA (OKLAHOMA) | 5,010 | 445 | Browse |
| 7 | IOWA (IOWA) | 4,128 | 95 | Browse |
| 8 | NORTH CAROLINA (NORTH CAROLINA) | 3,642 | 1,652 | Browse |
| 9 | MONTANA (MONTANA) | 3,029 | 214 | Browse |
| 10 | NEBRASKA (NEBRASKA) | 2,961 | 160 | Browse |
| 11 | VIRGINIA (VIRGINIA) | 2,711 | 440 | Browse |
| 12 | SOUTH DAKOTA (SOUTH DAKOTA) | 2,549 | 93 | Browse |
| 13 | SOUTH CAROLINA (SOUTH CAROLINA) | 2,440 | 674 | Browse |
| 14 | ALABAMA (ALABAMA) | 2,266 | 228 | Browse |
| 15 | COLORADO (COLORADO) | 1,984 | 472 | Browse |
| 16 | NEW YORK (NEW YORK) | 1,939 | 450 | Browse |
| 17 | ILLINOIS (ILLINOIS) | 1,633 | 252 | Browse |
| 18 | CALIFORNIA (CALIFORNIA) | 1,534 | 875 | Browse |
| 19 | WYOMING (WYOMING) | 1,498 | 102 | Browse |
| 20 | PENNSYLVANIA (PENNSYLVANIA) | 1,492 | 788 | Browse |
| 21 | OHIO (OHIO) | 1,402 | 421 | Browse |
| 22 | MASSACHUSETTS (MASSACHUSETTS) | 1,340 | 336 | Browse |
| 23 | CONNECTICUT (CONNECTICUT) | 1,289 | 276 | Browse |
| 24 | ARKANSAS (ARKANSAS) | 1,271 | 197 | Browse |
| 25 | TENNESSEE (TENNESSEE) | 1,232 | 277 | Browse |
| 26 | MINNESOTA (MINNESOTA) | 1,156 | 58 | Browse |
| 27 | INDIANA (INDIANA) | 1,092 | 282 | Browse |
| 28 | FLORIDA (FLORIDA) | 1,080 | 105 | Browse |
| 29 | KENTUCKY (KENTUCKY) | 1,074 | 276 | Browse |
| 30 | MICHIGAN (MICHIGAN) | 1,039 | 161 | Browse |
| 31 | WISCONSIN (WISCONSIN) | 996 | 198 | Browse |
| 32 | NORTH DAKOTA (NORTH DAKOTA) | 950 | 55 | Browse |
| 33 | OREGON (OREGON) | 884 | 173 | Browse |
| 34 | UTAH (UTAH) | 879 | 283 | Browse |
| 35 | WASHINGTON (WASHINGTON) | 835 | 416 | Browse |
| 36 | NEW JERSEY (NEW JERSEY) | 830 | 232 | Browse |
| 37 | LOUISIANA (LOUISIANA) | 748 | 42 | Browse |
| 38 | NEW HAMPSHIRE (NEW HAMPSHIRE) | 665 | 162 | Browse |
| 39 | MAINE (MAINE) | 586 | 78 | Browse |
| 40 | WEST VIRGINIA (WEST VIRGINIA) | 564 | 447 | Browse |
| 41 | NEVADA (NEVADA) | 509 | 162 | Browse |
| 42 | MARYLAND (MARYLAND) | 425 | 107 | Browse |
| 43 | NEW MEXICO (NEW MEXICO) | 420 | 225 | Browse |
| 44 | IDAHO (IDAHO) | 406 | 105 | Browse |
| 45 | ARIZONA (ARIZONA) | 393 | 170 | Browse |
| 46 | VERMONT (VERMONT) | 371 | 69 | Browse |
| 47 | RHODE ISLAND (RHODE ISLAND) | 235 | 95 | Browse |
| 48 | ALASKA (ALASKA) | 111 | 31 | Browse |
| 49 | DELAWARE (DELAWARE) | 83 | 57 | Browse |
| 50 | PUERTO RICO (PUERTO RICO) | 36 | 36 | Browse |
| 51 | HAWAII (HAWAII) | 4 | 3 | Browse |
| 52 | CUMBERLAND (CUMBERLAND) | 1 | 0 | Browse |
| 53 | GUAM (GUAM) | 1 | 1 | Browse |
High hazard count reflects dams classified as High hazard potential — where failure could result in loss of human life.
Understanding State Dam Inventories
Why Some States Have More Dams
Agricultural states like Texas, Kansas, and Missouri built thousands of small farm ponds and irrigation dams over the past century. States with significant hydroelectric development — such as Washington and Oregon — have fewer but much larger dams. The National Inventory of Dams includes all dams that meet certain size or hazard thresholds, regardless of whether they are publicly or privately owned. Many of the smallest dams in the inventory are privately owned farm ponds built decades ago with little ongoing inspection.
High Hazard Does Not Mean Unsafe
A dam's hazard potential classification is determined by the consequences of failure, not by the probability of failure occurring. A high-hazard dam is one located upstream of populated areas, roads, or critical infrastructure — where a breach would likely cause loss of life. Many high-hazard dams are in excellent condition and have been carefully maintained for generations. The classification exists to ensure that the most consequential dams receive appropriate regulatory oversight and regular safety inspections.
Explore Dam Safety Data
Browse dams by hazard level, condition, or search by name.