In alt.home.repair, on Fri, 20 Sep 2019 20:05:35 -0700 (PDT),
wrote:

Hi,
Just built a 9x16 shed, raised up 12" on sonotube foundations at the corners and middle.

???

I'm hoping to avoid adding a rain gutter because I hate cleaning the leaves out of it. Neighbors suggested:
1. put a wide row of pavers around the shed perimeter to prevent the water from washing out the ground, but not sure how wide that should be.
2. put a wide row of decorative gravel or mulch, but that sounds like a maintenance headache.
I figure a bunch of readers must have had similar experiences.
Advice and suggestions appreciated.
Thanks,
Theodore.

Others may have more precise answers, but I'd put one paver where I
thought the most water would come off the roof, and then I'd go out in
the rain and see where the water landed and if one paver wide is enough.

If you have to put two rows, or even between consecutive pavers in one
row, there is some kind of fancy hi-tech sand you can put down that will
keep weeds from growing in between, but I forget its name. People here
or at hd will know its name. Or you could just let weeds grow and mow
them when you mow the lawn.