NZ WACA Adjustments

This layer provides the extents of the data incorporated into an adjustment which has been completed as a Wide Area Cadastral Adjustment (WACA). These adjustments are undertaken in areas where there is already substantial survey-accurate data, but there are some inconsistencies in the data resulting from small changes to geodetic control coordinates and/or the progressive submission of additional Cadastral Survey Datasets (CSDs). The improvement of coordinates is controlled by a mathematical adjustment process using a Least Squares methodology. The adjustment/integration process results in increased mapping accuracy of surrounding spatial objects (e.g. parcels), the effect of which is some new observations or parcels appear to move. The extent of the change largely depends upon the accuracy of the underlying data. In general, movements will be no more than 10cm, as the WACAs target areas where coordinates already have fairly high spatial accuracy.