6 rods? Really? What's the point? And they need to be 6ft apart from each other.

SIX rods???
And WHY #2cu to the rods???

Did the installer ever read a code book?

Either way, NO you cannot do as you ask. You could however splice to the #2 to the water pipe using an irreversible splice, such as a compression crimp. You can do this since you ran an over sized wire to the rods.
A grounding electrode conductor to a ground rod(s) need only be #6cu regardless of service entrance size.

Thanks everyone. The inspector wanted #2 copper, so I used it. I would use #4 otherwise. 6 rods is my idea, just to decrease the resistance. Rex Cauldwell recommends 8 rods [*]. Rods are not expensive :) but wire was not cheap :) Rods are 8 ft apart.

[*] Book: For Pros By Pros "Wiring A House", Rex Cauldwell

Rex likes spending other people's money. Ground rods do almost nothing in the functionality of a residential electrical system. So two is just as good as six IMO.

And like I said, you only need #6 if the wire is going to just a ground rod. And also, the wire only has to be continuous to the first rod. From that point they are bonding jumpers.

Thanks, petey_racer! This is very useful, wish I had asked this question earlier.