[
  {
    "field": "dataset",
    "description": "Great Salt Lake daily lake-balance dataset (2003\u20132025)"
  },
  {
    "field": "time_basis",
    "description": "Daily values organized by water-year chronology; the record begins 2002-10-01 (start of WY2003) and runs through the 2025 water year"
  },
  {
    "field": "date",
    "description": "Daily observation date"
  },
  {
    "field": "evapotranspiration_in",
    "description": "Daily evapotranspiration estimate (inches) from the KSLC Hargreaves-Samani climate series"
  },
  {
    "field": "precipitation_in",
    "description": "Daily precipitation (inches) from the KSLC climate series"
  },
  {
    "field": "south_arm_elevation_ft_ngvd29",
    "description": "Daily South Arm elevation referenced to NGVD29"
  },
  {
    "field": "north_arm_elevation_ft_ngvd29",
    "description": "Daily North Arm elevation referenced to NGVD29"
  },
  {
    "field": "south_arm_area_ac",
    "description": "South Arm surface area (acres) derived from Casey-Root bathymetry at the daily South Arm elevation"
  },
  {
    "field": "south_arm_volume_af",
    "description": "South Arm volume (acre-feet) derived from Casey-Root bathymetry at the daily South Arm elevation"
  },
  {
    "field": "north_arm_area_ac",
    "description": "North Arm surface area (acres) derived from Casey-Root bathymetry at the daily North Arm elevation"
  },
  {
    "field": "north_arm_volume_af",
    "description": "North Arm volume (acre-feet) derived from Casey-Root bathymetry at the daily North Arm elevation"
  },
  {
    "field": "hydromapper_total_area_ac",
    "description": "South Arm + North Arm combined surface area (acres). Farmington Bay and Bear River Bay are excluded. This is the storage boundary used for the Hydro Mapper exploratory reconstruction method on the Data & Datasets page -- do not use it for the canonical Basin Plan ledger, which uses all four Casey-Root compartments (South Arm, North Arm, Bear River Bay, Farmington Bay) from elevation_annual_1961_2025 or bathymetry_casey_root_ngvd29 instead. Note: elevation_annual_1961_2025 has a differently-scoped field of the same name (South Arm + North Arm + Bear River Bay) -- the two are not interchangeable."
  },
  {
    "field": "hydromapper_total_volume_af",
    "description": "South Arm + North Arm combined volume (acre-feet). Farmington Bay and Bear River Bay are excluded. This is the storage boundary used for the Hydro Mapper exploratory reconstruction method on the Data & Datasets page -- do not use it for the canonical Basin Plan ledger, which uses all four Casey-Root compartments (South Arm, North Arm, Bear River Bay, Farmington Bay) from elevation_annual_1961_2025 or bathymetry_casey_root_ngvd29 instead. Note: elevation_annual_1961_2025 has a differently-scoped field of the same name (South Arm + North Arm + Bear River Bay) -- the two are not interchangeable."
  },
  {
    "field": "bear_river_corinne_cfs",
    "description": "Daily Bear River flow at Corinne (cfs)"
  },
  {
    "field": "weber_river_plain_city_cfs",
    "description": "Daily Weber River flow near Plain City (cfs)"
  },
  {
    "field": "farmington_bay_cfs",
    "description": "Daily Farmington Bay inflow gage value (cfs); incomplete in early years"
  },
  {
    "field": "goggin_drain_cfs",
    "description": "Daily Goggin Drain inflow gage value (cfs); incomplete in early years"
  },
  {
    "field": "terminal_flow_af_day",
    "description": "Daily terminal inflow volume, acre-feet per day, equal to the sum of the four gage flows (bear_river_corinne_cfs, weber_river_plain_city_cfs, farmington_bay_cfs, goggin_drain_cfs) converted from cfs to acre-feet/day. Previously labeled terminal_flow_cfs; renamed 2026-09-16 because the values were already in acre-feet/day, not cubic feet per second -- applying a further cfs-to-af/day conversion under the old label would roughly double true flow. Do not reapply a cfs conversion to this field."
  },
  {
    "field": "lake_precipitation_af",
    "description": "Daily direct precipitation volume on the lake surface (acre-feet) as carried in the source file"
  },
  {
    "field": "reference_et_af",
    "description": "Daily reference evapotranspiration volume (acre-feet): the KSLC Hargreaves-Samani reference ET (evapotranspiration_in, converted to feet) multiplied by south_and_north_arm_area_ac. This is a reference-ET based volume, not an independently observed or salinity-adjusted open-water/brine evaporation measurement, and should not be treated as a validated lake-evaporation residual. Previously labeled lake_evaporation_af; renamed 2026-09-16 for accuracy."
  },
  {
    "field": "source_note",
    "description": "This cleaned dataset is a standardized version of the source file used to build the 2003\u20132025 storage change table"
  },
  {
    "field": "missing_data",
    "description": "Blank values indicate unavailable source observations; no interpolation is applied in this cleaned file"
  },
  {
    "field": "system_alignment",
    "description": "Column names are standardized to align with the climate, streamflow, elevation, and bathymetry datasets used elsewhere on gslaccounting.org"
  },
  {
    "field": "pre_2003_caution",
    "description": "This dataset's fully assembled daily component balance begins water year 2003 (2002-10-01). Elevation and main-gage streamflow series extend back to 1961 in other GSL Accounting datasets, but this reference-ET and gage-derived daily decomposition has not been assembled or validated for years before 2003. Do not extrapolate this methodology backward to pre-2003 years without independent validation."
  },
  {
    "field": "revision_note",
    "description": "2026-09-16: renamed terminal_flow_cfs -> terminal_flow_af_day and lake_evaporation_af -> reference_et_af, for unit accuracy. hydromapper_total_area_ac / hydromapper_total_volume_af were NOT renamed -- an initial rename to south_and_north_arm_area_ac / south_and_north_arm_volume_af was drafted to resolve the boundary-definition collision with elevation_annual_1961_2025, then reverted before publication because the live Data & Datasets page's AI prompts reference hydromapper_total_volume_af by its original name for the Hydro Mapper reconstruction method; renaming it would have broken that published methodology. The collision is instead addressed by the cross-referencing descriptions on both fields (see hydromapper_total_area_ac / hydromapper_total_volume_af above). Values are unchanged in this revision; only field names and descriptions were corrected. Added pre_2003_caution field. 2026-09-18: replaced 61 days (2025-08-01 through 2025-09-30) of bear_river_corinne_cfs, weber_river_plain_city_cfs, farmington_bay_cfs, and goggin_drain_cfs with USGS-approved daily values (the file previously held provisional USGS readings captured at end of WY2025, before USGS finalized them); terminal_flow_af_day recomputed for those 61 days accordingly. Net effect on the WY2025 four-gage streamflow total is +0.016 kaf (negligible at the kaf precision used throughout the site); individual days moved by up to several hundred af/day but the changes are largely offsetting across the window. Prompted by an external data-quality review."
  }
]