Kulachi (کلاچی) is a city named after the Kulachi tribe, and is the headquarter of Kulachi Tehsil (an administrative subdivision) of Dera Ismail Khan District in Khyber-Pakhtunkhwa province of Pakistan.

The system of irrigation is called Rod Kohi, a system of mountain channels or hill-torrents inundating the whole valley of Damaan ("Rod" means "channel" and "Koh" means "mountain" in Persian).

The Rod Kohi system based on "Kulyat Riwajat" (Fromulae and Traditions) governed the irrigation system ever since the Pathan tribes had moved into Damaan.

The British officers reduced all these to writing during their Land Settlemts in the later part of 19th century.

[2] The city population consists of two major ethnic groups, the Pushtuns and the Baloch who mostly speak Saraiki.