causative
obligated
secondary
accessory
affluent
bayou
beck
billabong
branch
brook
burn
client
collateral
confluent
confluent stream
conquered
contributing
creek
dendritic drainage pattern
dependent
effluent
feeder
feudal
feudatory
fork
inferior
influent
kill
leader
liege
minor
offshoot
prong
rill
rivulet
run
runlet
runnel
satellite
servile
stream
streamlet
sub
subdued
subject
subjugated
subordinate
subservient
tribute
Babylonian
Ethiopian
Sassanian
adjacent
estuary
fresh-water
highland
inland
inlet
navigable
nominal
puissant
reedy
rightful
steep-sided
subjugate
subterranean
swampy
tortuous
watercourse
woodland