Replacing the Alleyway Drain Cover

A few weeks ago, I cleaned out the drain to make sure it wasn't backed up.  The drain cover had been rusted so badly, that it was crumbling in my hands.  I decided to look for a new one.  Home Depot and Lowes didn't carry it.  It wasn't even that they didn't carry it, they didn't really know what I was talking about! 

I decided to check out the Plumbing store on Lawton - they have everything there!  Sure enough, they had it for $6.95.  I picked it up and laid it down - perfect. 

Now, I just have to figure out what to do about the gap fom the concrete to the drain opening!  You think there's some kind of rubber cement that'd do the trick?  I want to keep this drain from leaking into the garage.