The short answer
A drone vs dam inspector comparison favors the drone for visual surveys of spillways and high concrete faces where rope or lift access is the largest share of a visit. A drone does not replace the independent engineering inspection that FERC Part 12 requires, and a camera cannot judge what lies inside the concrete. Use a drone to see hard-to-reach surfaces and keep an inspector on the job of judging the structure.
Key takeaways
- A drone makes the strongest case where rope or lift access is the largest share of a spillway or face visit.
- A drone replaces the access trip, not the engineer's judgment under Part 12.
- Measure current access hours on one structure before deciding.
- Staffing stays in the loop, since flight planning, flying and image review need trained people.
- Check BVLOS rules and waivers before planning any longer-range flight.
Drone vs dam inspector at a hydroelectric dam: which makes sense?
For most hydroelectric dams, a drone makes sense for the visual survey of spillways, piers and high concrete faces, while a dam inspector still makes sense for the engineering judgment. The drone earns its place where today's visit means rigging a rope crew or booking a lift just to get eyes on surfaces. It does not earn its place as the only look at a structure, and it does not replace the engineer who decides what the pictures mean.
The regulatory frame matters. Licensed hydro projects fall under FERC Part 12 dam safety rules, and the independent consultant safety inspections that Part 12 requires are arranged by the licensee on top of FERC staff's own inspections. A drone can produce the photographs and survey data that feed those inspections, but it cannot stand in for the consultant's review.
A drone makes less sense when the work is inside the structure, when the reach is short, or when the site has no workable flight path. Gate chambers, galleries and penstock access still need people with the right permits and training. Decide first whether the job is to see a surface that is hard to reach or to judge a structure. The first points to a drone, and the second points to a person with the right credentials.
What does a dam inspector actually do in a shift?
A dam inspector's shift at a hydro site is a sequence of checks, not a single climb. Typical work includes walking the crest and abutments, reading instruments that track seepage and movement, checking gate operation and drainage, and logging anything that changed since the last visit. The inspector records what is seen and reports it up the chain, on a schedule set by the owner's dam safety program and the license conditions.
Access is where the time goes. Spillway piers, the lower reaches of a concrete face and the upper parts of a gate structure often need a rope crew, a lift or a boat. Industry write-ups describe rope and crane access as expensive, with significant set-up, testing and move time when done correctly. Those hours are what a drone can change. The judgment the inspector brings does not change.
The inspector also decides what needs follow-up. A stained joint or a hairline crack gets a photo, a measurement and a note for the engineering team. A drone can capture the photo from a distance and produce a repeatable image set. Whether the crack is moving needs instruments or a person on the surface, and no camera settles that alone.
- Reach to spillway piers
Drone
Camera works from a flight path or standoff position, with no rigging
Dam Inspector
Needs rope, lift or boat access, planned ahead
- Surface images
Drone
Overlapping images from a repeatable route, easy to compare between visits
Dam Inspector
Trained eye that can walk the surface and notice what the camera angle misses
- Judgment on significance
Drone
None, it records only
Dam Inspector
Engineer or inspector decides what needs follow-up
- Weather and light
Drone
Wind, rain and glare can ground a flight
Dam Inspector
Works in more conditions with the right gear, though unsafe conditions still stop work
- Interior spaces
Drone
Poor fit in tight, dark or wet interiors
Dam Inspector
Can enter with permits and training
- Airspace rules
Drone
Needs FAA compliance, and beyond visual line of sight needs a waiver
Dam Inspector
No airspace rules apply
Which parts of a dam can a drone reach?
Spillways are the strongest case. Piers, the chute, the training walls and the stilling basin sit above water or along the crest, and a drone can photograph them from positions a rope crew must rig for. The wide faces of tall concrete dams are the other strong case, because the angle from the air covers a broad surface in one pass.
Federal work points the same way. The Bureau of Reclamation funded New Mexico State University to test drones on Elephant Butte Dam, looking for cracks, spalls and subsurface defects in the concrete. That inspection was described as the first Reclamation dam inspection using an unmanned aircraft system. It is a research project, not a published standard, so treat it as proof of method, not proof of routine.
The limits are real. A surface camera records what reaches the face, not what happens inside the concrete. Seepage patterns that appear only at certain water levels need a timed visit that a drone flight cannot guarantee. Gate galleries, drainage galleries and interior penstock access still need people. Use the drone as the surface eye and keep people on everything below the surface.
How many dams are there, and who staffs them?
The national count shows the scale. According to Geography Realm, relaying the National Inventory of Dams as of November 3, 2022, there were 91,720 dams in the 50 states, with Texas highest at 7,352 and Delaware lowest at 83. That count covers all dam types, not only hydroelectric ones, so treat it as a sense of scale rather than a list of sites.
The workforce is shrinking on paper. The Bureau of Labor Statistics reports that employment of power plant operators, distributors and dispatchers was about 43,700 in 2025, of which 29,800 were power plant operators, and projects a 10 percent decline from 2024 to 2034, about 4,700 jobs. Workers in this group typically receive extensive on-the-job training, so losing an experienced person takes a long time to replace.
Older BLS projections, quoted by POWER magazine, expected about 3,200 openings a year on average from replacement needs and a 15 percent decline from 2021 to 2031. A shrinking pool makes it harder to find a second person on short notice, so plan visits that do not depend on one. Safety is a second reason to cut exposure. The Electrical Safety Foundation International summarizes BLS data showing a utilities electrical fatality rate of 0.75 per 100,000 workers, against 0.11 for all occupations, from 2011 to 2024. A third-party listing that cites BLS survey data puts recordable injuries and illnesses in electric power generation at 1.7 per 100 full-time workers in 2024, a figure we have not checked against the BLS table itself.
How much labor time does access work take?
We could not verify hour figures for a dam inspection shift in this research pass, and any number here would be a guess. What can be verified is the shape of the time. Rope or lift access needs planning, rigging, a crew, equipment testing and a move between points, and each step repeats at every visit. A drone changes the access steps, but it adds flight planning, airspace checks, battery and data handling, and image review.
The honest comparison is per visit and per year. For a drone to pay off, the access hours it saves must exceed the new hours for planning, flying and processing. We found no quantified study of drone time savings against rope access, so the first site survey should measure both sides on one real structure before anyone signs off a program.
Hours also depend on reach. A spillway pier that needs a crew on each side is a different job from a crest walk that one flight covers. Count the access points per visit, the crew size each one needs, and how often the inspection repeats in the program cycle. Those three numbers, measured on your own structures, make the case or break it.
How does a team work with a drone at the dam?
The drone works best as a second set of eyes on the same team. The inspector plans the flight, checks the route before launch and reviews the images the same day. The engineer receives a standard image set rather than a verbal report from a rope crew. Staffing does not drop to zero. Someone must plan and fly, and someone must review, so a small plant has to schedule those tasks rather than assume they are free.
Off-hours work needs its own planning. Night flight needs lighting, planning and a trained crew, which is why most programs keep routine flights in daylight during staffed hours. Reserve after-hours work for emergency checks by a person, and log the reason each time.
Plan the handoff too. The image set should land in the owner's records with the same identifiers used for field notes, so the engineer can compare this visit against the last one without a second search.
What can a drone not do at a dam?
A drone cannot make the engineering call. It records what it sees, and it cannot judge stability, load paths or the significance of a crack without an engineer who knows the structure. FERC's Engineering Guidelines have required a Potential Failure Mode Analysis during Part 12 inspections since 2003, according to the Federal Register notice. A drone output is an input to that process, not a replacement for it.
A drone also cannot see inside concrete. Surface images show cracks and spalls that reach the face, but defects inside a structure need other tools, and the Elephant Butte test was aimed at exactly that limit. Results from a research project do not change what the regulator requires, and they do not give a plant permission to skip the consultant.
Weather and airspace are real constraints. Part 107 generally prohibits flights beyond visual line of sight, and those flights rely on individual waivers, according to AIN reporting. Wind, rain and glare on wet concrete can ground a flight planned for a clear morning, so keep a person on the crest as the backup plan.
What drone rules apply at a hydro site right now?
A drone flight at a hydro site falls under FAA rules, and the rules are moving. Part 107 generally prohibits beyond visual line of sight operations, and that work relies on individual waivers, according to AIN reporting. The FAA's overhaul of beyond visual line of sight rules was still approaching its finish line in the reporting we reviewed, so check the current status before planning any flight that depends on it.
Flights over people, near airports or over areas where crowds gather add their own requirements. Check them with the facility's airspace and security staff before scheduling, and treat a waiver as a condition of the plan, not a formality.
Decide who holds the flight authority before the first visit. Some plants contract the flights, some train staff to fly, and some hold authorization in house. Whichever path you take, the flight log and image retention need to match the owner's records.
How do you get started with a drone at a hydro dam?
Start with one structure. Pick the spillway or face where rope or lift access is the largest share of the visit, and measure both approaches over two or three visits. The measurement shows whether a drone saves time or only moves the work into planning, and that answer should drive the program.
We assess the site first. Our team looks at access points, airspace, staffing and the reporting path, then recommends the right robot for that site. The site assessment leads to a lease quote through financing. We handle deployment and integration, train your staff and service the equipment nationwide. The tool is matched to the structure, and the owner's engineer keeps the calls.
Ask for three things before you commit: a written flight plan for each structure, a named person responsible for airspace and waivers, and a documented path for images from the field to the engineer. A pilot on one structure gives you real hours to compare against the current visit, which is the only number that should move the decision.
Frequently asked questions
Want a drone at your hydroelectric dam?
Tell us about your site. We will recommend the robot, quote the lease, and keep it serviced.
Sources
- Federal Register, FERC Part 12 dam safety final rule (Order No. 880)
- Bureau of Labor Statistics, Occupational Outlook Handbook: power plant operators, distributors and dispatchers
- Geography Realm, dams in the United States (relaying the National Inventory of Dams)
- POWER magazine, power industry jobs outlook
- Electrical Safety Foundation International, workplace injury and fatality statistics
- SafetyRecord, electric power generation injury rate listing (third-party, citing BLS SOII)
- AIN, FAA BVLOS overhaul approaches finish line
- Geospatial World, NMSU to inspect Elephant Butte Dam using UAS