What is "chhachh"

Chhachh ( Punjabi and ) is a region consisting of an alluvial plain extending from Attock District of Punjab, Pakistan, southwest of Topi and Swabi. It is bounded on the north and west by the Indus river and is about long (from east to west) and broad. Percolation from the Indus makes the area extremely fertile, and it was the most fertile area of Rawalpindi Division. The population of the area is primarily made up of Hindko and Pashto speakers.