What are the biggest challenges or obstacles in civil engineering?

I’ve worked in a few different civil industries and I’m wondering what are the biggest challenges or obstacles you’ve noticed in your field?

For example:

In Land Development, it could be knowing all the rules and regulations for each county/city/DOT/etc.

In Water Resources, it could be something as small as HEC-RAS lacking a certain function you may find useful, or something bigger like municipalities making you upgrade the entire storm system on a site for just a minor improvement.