On Tue, 25 Oct 2016 19:30:52 -0700 (PDT), wrote:

If by filling the area in, you cause an increase in rain-water runoff,
or runoff at a faster rate, you might be liable for damages to downstream
properties if you do not get permits, approvals, etc, from the correct
governing authorities.

To answer your question, the county requires a "grading permit" if the
amount of soil is greater than 150 cubic yards.

They "recommend" we fill out forms even if we're gonna be below that, but
not if it's only a few truck loads.

Once those forms are filled out, they'll inspect periodically.