The NRES Graduate Student Handbook (p 18) clearly explains the importance of the Annual Review.
https://nres.illinois.edu/sites/nres.illinois.edu/files/images/2016%20NRES%20Grad%20Handbook.pdf
Each spring, NRES students are required to complete the Annual Review process and submit their completed forms to the department for their academic records. Your participation is mandatory, whether you are active or inactive. (This includes students who plan to graduate this May.)
If you have not already submitted your Annual Review form, you are late. Please contact Renee Gracon (gracon1@illinois.edu) if you need a copy of the form.