I don't think EV has anything built-in that will do this but I think you could accomplish the same goal by writing a VB query that does a nightly size check on the drive(s) then generates an email to you if the size is over a threshold you define. If you go to the Microsoft.com site and search for the Scripting Center you can find some VB samples, I know there is one up there that calculates free space, used space, etc; all you'd have to do would be to edit it to point to your partition drive, add the instruction to send email with size info, incorporate it into a batchfile and then schedule it as a Windows scheduled task. Sounds like a lot of work but the VB samples I've gotten from there are very good so it shouldn't take too long to tailor it to your needs.
Your batchfile would look something like this:
@ECHO OFF
cd c:\
c:\temp\indexstats.vbs <--change filename and path to whatever/wherever you save your vb script
:END
The only reason I am saying to call the VB script with a batchfile is I have a hard time getting VB Scripts to run via Windows schedule reliably.
Like I said, sounds like a lot of work, but it's not too bad. I've used the MS sample VB scripts to run on-demand directory info for partition sizes and it only took a few minutes to alter them to fit my environment. Adding the email component and automating it shouldn't be too bad. Just make sure you are picking a VB script that does queries and not changes... test your script very well before taking it live... one little change in the syntax and it could get ugly!