Dam repair, retrofitting, and decommissioning in the U.S. are way behind. The useful life of a dam is between 50 and 80 years, and according to ASCE’s Infrastructure Report Card, the average age of our nation’s dams is 57. Many are in need of maintenance or upgrades to bring them up to today’s standards, especially with the growing challenges of climate change. Yet the size, location, and construction of these critical pieces of infrastructure pose some unique challenges to inspectors.

Drones are one technology that may be able to help assess dam conditions faster and more safely than traditional inspections. Drone inspections can help dam owners document problems and prioritize the most urgent fixes. Using drone-generated 3D models, high-resolution imagery, and data analysis, drones can be used to rapidly detect potential problems in difficult-to-reach places — a process that may otherwise take days or weeks. 

Drones can also access places that a crew rappelling from ropes can’t. They reduce the need for climbing, hiking on rocky or unstable slopes, or working around dangerous machinery. And decision makers can prioritize repairs and upgrades based on more precise information while factoring in hazard levels and downstream consequences. 

Here’s why it’s so important to closely monitor dams, as well as a few ways drones can improve on traditional dam inspection practices.

Dam inspections protect life and property

High hazard potential dams are those that would cause direct loss of life and extensive property damage if they fail. The American Society of Civil Engineers estimates that since the beginning of this century, the number of high hazard potential dams in the U.S. has more than doubled. As rural areas develop, people and property are moving into areas that could be affected by dam failure, so anything downstream from dams — housing, roads, industrial and commercial development — is at risk if dam defects aren’t closely managed. 

Climate change realities — like once-in-500-years flooding that takes out dams and 100-year floods occurring annually — are another factor. They are straining water management systems as never before. The pace of dam inspections, repair prioritization, and upgrades has to pick up. Yet the challenge and expense of these maintenance practices means that even many high hazard potential dams don’t have any inspections on record with the U.S. Army Corps of Engineers’s National Inventory of Dams.

Drone data gives critical insights on infrastructure

Drones can collect rich data on dam structures, reservoirs, spillways, and more. They can reach hard-to-access areas and get results without putting workers at risk from water hazards, heavy equipment, or falls. And in many cases, drones can complete the work faster, which means dams can be inspected more frequently and at lower cost.

In a matter of a few hours, a drone can fly a large structure and collect the data to build a 3D model with centimeter-level accuracy. Using inspection tools that incorporate the drone’s high-quality cameras, engineers can detect even small cracks and examine them from multiple angles. And repair crews can better prepare ahead of time for the work that needs to be done.

Plus, a drone puts a wide range of data collection and analysis at your disposal. It can:

  • Detect defects or potential problems on external surfaces using high-resolution imagery.
  • Automatically mark deficiencies with coordinates and timestamps, making it easy to track their evolution over time.
  • Measure volumetric changes for embankments or stockpiles of materials.
  • Map and survey areas for new construction.
  • Generate 3D “digital twins” of existing structures.
  • Automate the process of finding and reporting on defects in combination with artificial intelligence and machine learning, doing rapid analysis on thousands of square feet of structure.

How drones can support dam inspections

Drones are a proven tool for both horizontal and vertical infrastructure inspections. They’re well suited to inspect many types of water containment structures: reservoirs, levees, wastewater systems, and even huge hydropower and diversion dams. Here are several use cases.

  1. Detecting and documenting cracks, spalls, and rust in retaining walls, spillways, abutments, above-ground penstocks, and more.
  2. Measuring dam crest settling and slope changes
  3. Monitoring vegetation growth at spillways, dam crests, or slopes
  4. Measuring erosion of embankment surfaces and documenting progress of erosion gullies
  5. Checking for debris in spillway inlets
  6. Inspecting power lines at hydroelectric dams
  7. Inspecting and documenting riprap condition
  8. Monitoring sediment movement in reservoirs
  9. Rapid damage assessments following disasters
  10. Monitoring construction progress
  11. Creating 3D models of hydraulic structures
  12. Detecting animal burrows and fence damage

Help on the way for dam infrastructure

Legislation that would revitalize American infrastructure has some momentum. One proposed bill would allocate more than $1.6B to both private and public dams. The funds would pay for upgrades to existing dams and for the removal of those past their useful life.

Drone technology can play an important part in speeding up this work. And whatever level of funding is ultimately passed, drones may be able to help infrastructure investment go farther while reducing or eliminating risks associated with dam inspections.

Interested in using drones to inspect critical infrastructure? See how Skyward’s Mapping & Modeling solution can help you take advantage of drones and the data they provide!

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