Case Study:

SITE SURVEY AND VOLUMETRIC ANALYSIS

 

In the Western United States, ranching and agriculture rely heavily on water to keep their farms and ranches alive. Water rights are governed by complex rules and agreements in order to provide fair use for those who need it.


Flight Evolved was contacted by our client, a rancher in Eastern Montana, about the possibility of surveying a newly constructed watering reservoir on his ranch. In order to use the water that would fill the reservoir he needed to be able to accurately describe the location of the reservoir and estimate its holding capacity for a new water rights filing required by law.

Our Flight

The Reservoir project was a small area to map but required extra precision in depth to insure an accurate volume estimate. To give a more accurate 3D model of the pond we flew an overhead grid with 70% overlap followed by a high altitude orbit and a lower altitude orbit with 60% overlap in each orbit. With the small size of this project our flight time was under 12 minutes.

The Data

This project could have been completed with just the overhead grid, but we added the orbits to give an angled view from our camera. This allowed us to better capture detail under the trees and create a more precise surface model. The information that our client needed most was an accurate GPS grid coordinate for the center of the reservoir, and a physical description of the reservoir including size and volume. We started by determining the level of the spillway and using that level to determine the border of the reservoir.

 

Once the border of the reservoir was established we digitally removed the trees and shrubs from inside the newly created reservoir and used computer modeling software to create a 3D model of the pond itself. With all the distractions removed we could then determine the volume, surface area, and dimensions of the reservoir.

Finally we used several manual tie points to accurately position our model on a map so that we could confidently provide GPS coordinates for the center of the reservoir.

Results

With 12 minutes of flying and a few hours of computer work we were able to provide a highly accurate documentation for our clients water rights application. As a result of the high quality data his time sensitive application was quickly approved. The only question he had to answer from the local water rights office was, “Who prepared your application? Its the best we’ve ever received!”