Egyptians became skilled in surveying because

The Nile river annual flooding erased property markers each year

The Egyptian civilization was located along the Nile, 25km on each side of the longest river in the world,probably rivaled only by the Amazon. The Nile flooded yearly and the Egyptian priests and people had to develop sets of skills that marked not only the flooding patterns but also the property markers of the people. Nevertheless,it is this flooding that also served to make the Nile valley fertile, and as such flooding was an important event.