Stages and Discharges of the Mississippi River and Tributaries and Other Watersheds in the New Orleans District

Gages operated by the New Orleans District are generally inspected at least once each year. The datum used is that of the 1929 National Geodetic Vertical Datum by the National Ocean Survey. Gages are being adjusted to agree with benchmark changes also furnished by the National Ocean Survey. Refer to the General Information section at each station for specific adjustments. Gage readings are checked against inspection reports and comparative hydrographs and are corrected where the need is indicated. Stages are readings of water surface elevations expressed in feet above the zero or reference point of the gage. The reference point is referred to either National Geodectic Vertical Datum of 1929 NGVD or mean low gulf datum. Mean low gulf is 0.78 foot below NGVD. National Geodetic Vertical Datum of 1929 is used in lieu of Sea Level Datum of 1929 MSL . Discharge is the quantity of water flowing past a cross section of the stream in a unit of time. It is expressed in cubic feet per second. Discharge data consist of a brief description of the gaging station, results of discharge observations, and where determined, computed daily flows. Annual highest and lowest stages are reported for most of the daily gage stations. In determining these extreme records, all available gage data, including continuous recorder charts, twice-daily gage readings, and gage records taken from discharge notes, inspection reports, etc., are used. The time of occurrence usually is reported for the annual highest stage but not for the annual lowest stage.