A lot of what you have listed is more about knowledge of local ecosystems - not "civil engineering, surveying, agriculture, navigation, mathematics, etc.". As

A lot of what you have listed is more about knowledge of local ecosystems - not "civil engineering, surveying, agriculture, navigation, mathematics, etc.". As to some of the more general science knowledge though, subsequent societies could certainly replicate the scale and precision of cities like Angkor Wat or Tikal. Likewise, later ocean navigators had far more sophisticated navigation methods, using such tools as the compass and the kamat. As to qanat and wind-catcher architecture, it wasn't ever really lost... I'll grant you that knowledge of public health has been very uneven, though it has generally been on the upswing in the past couple centuries (as objectively measured by life expectancy and the burden of communicable diseases), nothwithstanding certain missteps (such as adopting droplet theory which was less accurate than miasma theory).