 To convert the marshes into arable land, canals were constructed to drain the water of the marshes into the river.By the late 17th-century, the marshland had been converted into mills, sugar plantations, fruit trees plantation and paddy field.In 1681, the flow of Ciliwung was diverted toward the east along the Postweg (now Jalan Pos) to reach another new canal, the Gunung Sahari Canal.