Ground-truthing of dominant substrate and vegetation across the subtidal, intertidal and margin areas of the Kakanui estuary was undertaken on foot and by boat by Salt Ecology over January 2021. Features were recorded directly onto 0.2m/pixel rural aerial photos flown in 2017 and sourced from LINZ online data service. Sampling of bottom sediment and water column measures of pH, salinity, dissolved oxygen, temperature and chlorophyll-a were made at 11 sites. Salt Ecology in-house scripting was used to validate 2021 field codes and check for topology errors. In the 2021 master layer, "Orig_Code" is the original 2021 field code and "FieldCode" shows any changes made. Spatial accuracy for features clearly visible on aerial photos (e.g. salt marsh, cobble fields) is ~2 metres. Spatial accuracy for features difficult to distinguish on aerial photos (e.g. where boundaries represent a habitat transition from mud to sand) is ~10 to 20 metres depending on the extent of ground truth undertaken. Field codes present features in order of their dominance; e.g Lesi Sare = (Lesi (rushland) dominant to Sare (herbfield)). Vegetation height is able to be derived from the structural class of features; e.g. Lesi (rushland) is taller than Sare (herbfield). Catchment land cover was sourced from Landcare Research Land Cover Database (LCDB5, 2018). Sand and mud substrate classifications were validated through the laboratory analysis of representative samples for sediment grain size.