Historical Water Level Data of the Greater Charleston Region (1975-1992), Previously Unpublished by NOAA

Water level data from the greater Charleston Harbor Region was collected by NOAA from 1975 to 1992 and was previously unpublished. The unpublished data includes 18 sites on the Ashley River, Cooper River, Wando River, and at Fort Sumpter (Figure 1). The data units are meters and have hourly intervals in Eastern Standard Time. These data are not published and only available by request because have not gone through the rigorous modern NOAA quality control process. We compared the historical records to modern data (e.g., Dykstra et al., 2022; USGS), finding minimal errors. Datum information from NOAA (e.g., https://tidesandcurrents.noaa.gov/benchmarks/8664022.html) were also validated and are summarized below with NAVD88 corrections, where available (Table 1). Some additional quality control was completed for 8664531 (8664531_QC.csv), identifying poor data from the first few days and low water levels where the record was unusually flat (<-0.75m MLLW). These former data points were replaced with ‘NaN’ and the later were replaced using a spline interpolation. Further data details are shown in Table 1, including site locations and length of records. This effort supports the research of Dykstra et al. (in-prep).