Sewer Spoil Calculation

Alternately if you're planning to do sewer drainge excavation for pipework, you can use a couple tool options. While not a hydraulic contractor myself, I would suggest that you can use the following,

- trenching tool is probably the intended tool option, uses centreline.
- slope tool if you have known depths relative to the topography and adjust the width of the excavation to suit, not the intended tool use but its a handy option
- feature surfaces is another possibile option with a couple neat ways you could set the depths for excavation.

Be mindful of the side batter ratio as well, if trenches are deep, you can probably dial this back if you're going to use trench shoring, particuarly modular units handled by excavation equipment.

Then using your exported report, you'd need to then add your bulking factor to suit accordingly.