Security Popup about a Driver when Appending a Material Every time I append one specific material from my library, I am given this error:

I usually just ignore it and continue on my merry way. However today I decided to fix it. I don't know anything about drivers currently, other than that they simply allow you to modify the behavior or settings of one object to another using some kind of formula. I've gathered that 'water_drive_xtm(self)*(var/100)' is the formula in question.
Here's a gif that shows where the driver formula resides in the material:


Does anyone know what this script is actually doing? It's a water material if that helps.
How do I remove the driver so I stop getting these warnings?

Edit: Here's the blend file if it helps explain what the driver is doing:
You can right click it and hit Delete Drivers.
It looks like it's randomizing the origin location of the noise textures hooked up to the bump map to give it a more random appearance based on whatever parameter that driver was looking at.