High Hazard Dams With Overdue Inspections

High hazard dams — those where failure would probably cause loss of human life — typically require regular inspections to identify safety deficiencies before they become emergencies. Most states mandate inspections every 1-5 years for high hazard dams.

Currently, 7,777 high hazard dams in the National Inventory of Dams show a last inspection date more than 5 years ago. While some of these may reflect data reporting delays rather than missed inspections, the gap between the recorded inspection date and today raises questions about ongoing monitoring.

This data comes from the NID and may not reflect inspections conducted but not yet reported to federal databases. For the most current inspection status, contact your state dam safety program.

Overdue Inspections by State

StateOverdue High Hazard DamsOldest Inspection
North Carolina115501/01/2001
Texas93801/03/2024
Georgia46801/01/2005
Missouri45201/01/1991
South Carolina36901/03/2024
California33701/06/2026
Mississippi25501/05/2023
New York24401/02/2024
Pennsylvania24301/04/2021
Kansas24201/03/2020
Ohio21601/21/2021
Colorado20001/09/2024
Virginia18801/06/2021
Washington14601/04/2019
Tennessee14501/04/2024
Massachusetts13501/05/2024
West Virginia13001/04/2016
New Mexico12901/14/2021
Connecticut11801/05/2024
Kentucky11701/29/2025
Utah11303/23/2023
Nevada11301/31/2022
Oklahoma10301/01/1980
Indiana9901/01/1962
New Jersey9001/04/2024
Illinois9002/02/2024
Nebraska8903/28/2024
Hawaii7701/09/2025
Arizona7701/08/2024
Wisconsin6502/22/2023
Montana6101/04/2021
Arkansas5501/01/2000
New Hampshire4803/23/2021
Vermont4501/01/1987
Oregon4501/20/2022
Iowa4303/15/2021
Maryland4201/29/2024
Wyoming4104/05/2022
Michigan3701/01/1901
Idaho3503/15/2023
Florida3201/29/2025
Alabama3201/04/2000
Delaware2804/11/2024
Maine2104/01/2022
Puerto Rico1801/10/2020
South Dakota1504/09/2023
Minnesota1502/23/2021
Alaska705/20/2019
North Dakota605/21/2025
Louisiana404/10/2021
Rhode Island303/28/2017
Guam105/07/2025

Largest Dams With Overdue Inspections

DamStateHeight (ft)Last InspectionYears AgoConditionEAP
Thompson MtisIdaho78906/05/20197FairYes
OrovilleCalifornia77006/06/20233FairYes
Hoover DamNevada73002/09/20233Not AvailableYes
Dworshak DamIdaho71706/23/20224Not AvailableYes
New Melones DamCalifornia62504/27/20224Not AvailableYes
Shasta DamCalifornia60202/11/20224Not AvailableYes
Yankee Doodle Tailings DamMontana57002/12/20206SatisfactoryYes
Hungry Horse DamMontana56406/24/20215Not AvailableYes
Trinity DamCalifornia53804/20/20224Not AvailableYes
Yellowtail DamMontana52504/25/20233Not AvailableYes
North Block Tailings Impoundment DamNevada52005/13/20206Not RatedYes
Cougar DamOregon51905/17/20224Not AvailableYes
Flaming Gorge DamUtah50206/29/20224Not AvailableYes
Fontana DamNorth Carolina48002/15/20242Not AvailableYes
Carters Main DamGeorgia46405/09/20233Not AvailableYes
Detroit DamOregon46304/13/20260Not AvailableYes
Round ButteOregon44006/08/20224FairYes
New Waddell DamArizona44004/19/20224Not AvailableYes
Pine Flat DamCalifornia44005/20/20215Not AvailableYes
Mud Mountain DamWashington42505/15/20215Not AvailableYes
PyramidCalifornia42205/06/20251FairYes
Swift No. 1Washington41205/03/20224FairYes
Harmar Refuse BankPennsylvania41004/02/20206SatisfactoryYes
Little Blue RunPennsylvania40003/26/20215FairYes
Jordanelle DamUtah39107/09/20206Not AvailableYes
Green Peter DamOregon37806/11/20251Not AvailableYes
BoundaryWashington36005/24/20224FairYes
Abiquiu DamNew Mexico35404/25/20233Not AvailableYes
Arrowrock DamIdaho35005/05/20215Not AvailableYes
Watauga DamTennessee33203/27/20251Not AvailableYes
AlderWashington33001/23/20233SatisfactoryYes
Ridgway DamColorado33006/10/20206Not AvailableYes
Cerrillos DamPuerto Rico32306/16/20215SatisfactoryYes
Ruedi DamColorado32205/16/20224Not AvailableYes
Parker DamArizona32003/11/20224Not AvailableYes
MerwinWashington31304/19/20224FairYes
Cobre Main Tailings DamNew Mexico31007/01/20206SatisfactoryYes
OlivenhainCalifornia30905/28/20251SatisfactoryYes
Bartlett DamArizona30903/04/20206Not AvailableYes
Green Mountain DamColorado30901/09/20242Not AvailableYes
Hiwassee DamNorth Carolina30704/09/20251Not AvailableYes
Horse Mesa DamArizona30504/05/20233Not AvailableYes
Monticello DamCalifornia30403/10/20206Not AvailableYes
Mathies Mine Refuse Area Pond #2Pennsylvania30004/01/20215FairYes
Lewis SmithAlabama30003/23/20224SatisfactoryYes
Jennings Randolph DamMaryland29606/03/20242Not AvailableYes
Seminoe DamWyoming29506/28/20233Not AvailableYes
Amistad DamTexas28701/31/20242PoorYes
Diamond Valley LakeCalifornia28402/04/20251SatisfactoryYes
Alamo DamArizona28302/19/20251Not AvailableYes
Laurel DamKentucky28203/30/20224Not AvailableYes
Merrill Creek Main DamNew Jersey28006/12/20242SatisfactoryYes
Harry L. Englebright DamCalifornia28006/27/20242Not AvailableYes
Bradbury DamCalifornia27902/16/20233Not AvailableYes
Lookout Point DamOregon27606/13/20242Not AvailableYes
Cushman No 2Washington27505/19/20224SatisfactoryYes
Ridges Basin DamColorado27306/28/20233Not AvailableYes
Soldier Creek DamUtah27206/08/20215Not AvailableYes
Cushman No 1Washington27205/19/20224FairYes
Palisades DamIdaho27005/11/20215Not AvailableYes
Alcova DamWyoming26506/09/20215Not AvailableYes
CulmbackWashington26205/14/20215SatisfactoryYes
East Canyon DamUtah26006/01/20233Not AvailableYes
Table Rock DamMissouri26005/24/20233Not AvailableYes
Ririe DamIdaho25305/04/20215Not AvailableYes
Sugar PineCalifornia25105/22/20251SatisfactoryYes
CoolidgeArizona25002/24/20233FairYes
Cedar SpringsCalifornia24905/08/20251FairYes
Mount Morris DamNew York24906/09/20251Not AvailableYes
Lost Creek DamUtah24805/04/20224Not AvailableYes
Norfork DamArkansas24806/05/20242Not AvailableYes
Ball Mountain DamVermont24707/09/20242Not AvailableYes
Hughes Hollow Slurry ImpoundmentPennsylvania24503/19/20215SatisfactoryYes
Arthur R. Bowman DamOregon24506/22/20215Not AvailableYes
Pueblo DamColorado24504/10/20197Not AvailableYes
Oahe Dam - Fort Yates Flood Protection ProjectSouth Dakota24506/06/20233Not AvailableYes
Kortes DamWyoming24406/28/20233Not AvailableYes
Mcelroy Run DamWest Virginia24302/28/20251SatisfactoryYes
Applegate DamOregon24205/14/20242Not AvailableYes
Deer Creek DamUtah24007/08/20206Not AvailableYes
Blakely Mountain DamArkansas24004/25/20242Not AvailableYes
Mount St. Helens Sediment Retention StructureWashington23903/10/20224Not AvailableYes
El CapitanCalifornia23705/07/20251PoorYes
Smith Mountain Combination Pump StorageVirginia23704/13/20224SatisfactoryYes
Conchas DamNew Mexico23505/30/20251Not AvailableYes
Tygart DamWest Virginia23404/26/20233Not AvailableYes
Chino Mines Tailings Dam No. 7New Mexico23006/30/20206SatisfactoryYes
Chief Joseph DamWashington23006/21/20224Not AvailableYes
John Day Lock And DamOregon23001/20/20224Not AvailableYes
Pacificorp - Electric LakeUtah22906/20/20233SatisfactoryYes
Trampas CanyonCalifornia22904/03/20251SatisfactoryYes
Beaver Dam - Saddle Dike 3Arkansas22906/09/20251Not AvailableYes
Sanford DamTexas22803/03/20224Not AvailableYes
Little Goose Lock And DamWashington22605/01/20233Not AvailableYes
New Lake ArrowheadCalifornia22505/22/20251SatisfactoryYes
Salmon FallsIdaho22405/15/20206FairYes
San Joaquin ReservoirCalifornia22405/07/20251SatisfactoryYes
Mormon Flat DamArizona22402/05/20206Not AvailableYes
Canyon Lake Dam - Dike ATexas22402/02/20233Not AvailableYes
Canyon Lake DamTexas22402/02/20233Not AvailableYes