Do the ridged roofs on the houses in Bermuda actually increase rain capture?

Question

Saw a video recently looking at houses in Bermuda and rain collection. They claimed that the ridges on the roof increase the surface area in order to increase rain capture.
Surely rainfall is even over a surface regardless of terrain and therefore a ridged roof would collect the same amount as a smooth slopes roof?

In: 16

Answer 1

Bermuda is a rock in the Atlantic Ocean 600 miles east of North Carolina.

The roofs are made of limestone and the ridges channel the water in a pattern across the limestone in an effort to clean it, then it lands in a collection barrel.