Through this stretch of dasht the drainage from the main water-divide breaks downwards to the plains of Herat, where it is arrested and utilized for irrigation purposes.
The Hab river, which forms the boundary west of Karachi; the Purali (the ancient Arabus), which drains the low-lying flats of Las Bela; the Hingol (the ancient Tomerus) and the Dasht, which drain Makran, are all considerable streams, draining into the Arabian Sea and forming important arteries in the network of internal communication.
It is on the whole a route across open plains and hard, stony " dasht" - a route which would offer no great difficulties to that railway extension from Chaman which has so long been contemplated.