Discharge on clay is the regulated part
Preservation rarely reaches below-grade work; stormwater does. A system that collects water at the foundation has to put it somewhere, and on Piedmont clay that does not absorb readily, a discharge a few feet from the wall simply returns it. City stormwater expectations govern where it may go. Note also that true basements are uncommon here — many enquiries are actually crawlspace problems.
Official sources
Establish what you have, then where water can go
Citywide guidance cannot tell you whether you have a basement or a crawlspace, where a system could discharge, or where water is entering. Establish all three on the parcel before comparing any quotes.
Research date
Checked in mid-2026 -- maps and rules shift over time, so verify before relying on this.