distributary

Etymology

distribute + -ary

adj

1. That distributes.
   A posthumous child is as much entitled to a distributary share, under the statute of distributions, as one that is born at the time of the death of its father […] 1816, Tapping Reeve, The law of baron and femme, of parent and child, of guardian and ward, of master and servant, and of the powers of courts of chancery
   […] improving the channels in a distributary unit. 1991, Leslie E. Small, Farmer-Financed Irrigation: The Economics of Reform
   These deposits are commonly punctuated by metre-scale fining-upward, medium-grained, cross-bedded sandstones, interpreted as terminal distributary channels. 2014, Allard W. Martinius, editor, From Depositional Systems to Sedimentary Successions on the Norwegian Continental Margin, page 379

noun

1. (hydrology) A stream of water (either natural or artificial) that branches off and flows away from a main stream channel.
   The bed of the distributary is at a slight elevation above that of the main canal, and in the latter is placed an ordinary check regulator controlled by flashboards […] 1894, Herbert Michael Wilson, Engineering Results of Irrigation Survey, U.S. Government Printing Office, page 270
   The physical condition of the distributary itself is in bad shape due to poor maintenance over longer periods of time, especially in the head reach. 1998, Sediment Behavior of Sangro Distributary, Mirpurkhas Sub-division, Sindh, page 6
   […] stretches of blowing sand and frequent changes in course of its distributaries, does not have the dense population characteristic of other alluvial districts in the Indian subcontinent. 2001, James R. Penn, Rivers of the World: A Social, Geographical, and Environmental Sourcebook, page 115