Sewage backing up, a broken water line, something actively flooding, a trench that has to be dealt with today. Call, don't fill out a form, and say the word emergency up front so we can triage it on the phone.
Bids, planning, new construction schedules, a septic system you're thinking about for next spring. The form is actually faster for these, because it gets the details right the first time instead of over three voicemails.