Yes, that is something we can do. The ability to add road closures is usually limited to Level 3 editors but, from our PM's a year ago, you have shown that you are interactive and want to contribute.
Let's go over a few things:
First, I suggest you read through https://wiki.waze.com/wiki/Real_time_closures
Next, be aware that if you edit a road segment (split it, merge it, etc.), you will not be able to close it immediately. You will have to wait until the next tile build.
Finally, at this time, you will only be able to close segments of L2 or lower. If you need a closure on a higher level road, you'll have to have a L3 editor place them. (If interested, we'd love to have you join our North Dakota Google Hangout, where we can interact much more quickly and can handle such issues). As your edits and experience increase, we can look at getting you leveled up to L3. L3 editors are auto-granted closure access.
FYI, I'm based out of Bismarck. Feel free to contact me anytime with any question, I'm here to help, as are any of the guys listed here: https://wiki.waze.com/wiki/North_Dakota#Area_Managers