Depending on your system you might have already /usr/local/lib included in your ld configuration. If this is not the case (like on my test debian box) you can add it inside /etc/ld.so.conf, or as a nice debian “thing” you can just create a new file inside /etc/ld.so.conf.d/ like:
vim /etc/ld.so.conf.d/libevent.conf
##add a line containing:
/usr/local/lib/
ldconfig -v