aggrades

That balanced condition called grade, where a river neither degrades its bed by erosion nor aggrades it by deposition, is first attained along reaches of soft rocks, ungraded outcrops of hard rocks remaining as barriers which give rise to rapids or falls.

The Elements of Geology William Harmon Norton 1900

Its ungraded branches may thus bring down to its lower course more waste than it is competent to carry on to the sea, and here it aggrades its bed and builds a flood plain in order to gain a steeper gradient and velocity enough to transport its load.

The Elements of Geology William Harmon Norton 1900

In places it leaves its bed undisturbed and in places aggrades it by deposits of the ground moraine.

The Elements of Geology William Harmon Norton 1900