This one comes up from time to time - how do I determine where my pond capacity line is for e.g. 20% and 80% full.
-
The key is to create your Full Capacity line and create a surface from it - call it Pond Top
-
Then determine your volumes at e.g. 0.05’ intervals using the Earthwork Report
-
Copy the report values into excel and create a cumulative column and sum up the band volumes to each elevation interval
-
Now take the cumulative total and determine what 20% of the volume represents
-
Now take the cumulative volume and determine what 80% of the volume represents.
-
Now look down the cumulative volume column to find the 20% and 80% volume numbers (or the closest number to those percentage points. These will be your two contours that you need to create
-
Now use the Create Contour at elevation, and enter the specific values that you determined from the list. Name the first contour 80% and the second one 20%. These contours are your capacity lines.
-
If you need to check the numbers, explode the contours to make them 3D lines. Once they are 3D lines you can create a surface for each one - call the surfaces 80% and 20%.
-
Now you can see those surfaces in the Surface Slicer and 3D Views.
-
Now you can run the Earthwork Report between each of these surfaces and the Finished Grade and the results should match the initial volume report.
-
If everything jives, these are the lines you need for the staking operation in the field.
Video shows you how