When downloading data in CSV format, there is either -9998, -9997, or “m”. What do they stand for?
“-9998” stands for Below Rating Table, “-9997” stands for Above Rating Table, and “m” stands for missing value. Both values, -9998 and -9997, are used for flow data only. River flow data for stations with river stage data are computed using a specific rating table/rating curve for each particular station. When the river stage is above or below the available rating table, a flow cannot be computed.