Water Level, Low : In nontidal locations, the normal low water level; in single tidal areas, mean low water; and in dual tidal areas, mean lower low water
NFPA 307 Standard for the Construction and Fire Protection of Marine Terminals, Piers, and Wharves, 2000 ed. https://www.nfpa.org/assets/files/AboutTheCodes/30 7/307-A2005-ROC.pdf, (Std: Const and Fr Prac of Mrn Term , Piers, and Wharves - Amer) {295 NFC}