[Jamboy]

I have a roof drain that I want to direct over a bluestone walkway. How much damage will this cause? The roof area is around 300 sq. ft. We are in the 3" 100 year rain area. Clay soil eliminates using dry well. Garden area is fully enclosed by the walkway. Drain away is down grade to grassy area across walk.

 

[Ron6519]

In a 100 years or so you'll be kicking yourself about this decision.
Ron

 

[Jamboy]

I sense sarcasm but want to be sure.

I was concerned about the effect on the mortar between and under the Bluestone.

 

[Ron6519]

I sense sarcasm but want to be sure.

I was concerned about the effect on the mortar between and under the Bluestone.

The water you referred to getting on a stone will not damage it. But you didn't really give all the information required for a relevant answer. The answer will also depend on where you live, which I don't see. Water getting in and under stones in a freezing environment wiil do much more damage then stones in a temperate region.
I have a leader draining on a blustone patio set in sand in NY. I don't need to worry.
It might help if you posted a picture. The patio's condition will also play a part.
Ron