Because the annual Nile flood erased field boundaries, Egyptian officials developed systematic surveying to re-measure and re-allocate farmland each year, using knotted measuring cords and standardised cubits. Nilometers, calibrated stone gauges set into riverbanks and temples, recorded the height of the flood to forecast the harvest and set the tax assessment. Scribes maintained registers of plots, owners and yields, an early land cadastre tied directly to revenue. Surveyors, the 'rope-stretchers', became a recognised technical profession.
Egypt institutionalised land measurement, registration and flood prediction as tools of taxation and administration, establishing the cadastral surveying on which all later urban land governance depends.