Apache config resetting after every OS update

This is infuriating. I have a lot of custom settings on my development Mac and every time there is an OS upgrade I have to go back and reset everything. I read somewhere that the old config is saved in httpd.conf~previous, but that file doesn't contain my changes either. It seems to be more or less the same as the new one. Questions Why does this happen on every Mac update? What can I do to avoid this? Should I install a second copy of apache with brew? and if I do that, is it reasonably possible to disable the built-in MAMP? All solutions are greatly appreciated.