Why does Barbados have few streams and no significant rivers or lakes?

Barbados lacks significant rivers and lakes primarily because of its unique geological composition. The island is largely covered by a thick cap of coralline limestone, which is highly porous.12

When it rains, the water does not collect on the surface to form rivers or lakes; instead, it percolates quickly through this limestone layer. This drainage feeds into underground streams, which serve as the primary source of the country's water supply.1