environmental
assist
background
bank
barrier
button
control
danger
dangerous
defence
defend
disaster
environment
flood
flow
flowing
header
heading
help
high
icon
illustration
illustrative
insignia
isolated
lake
leak
leakage
level
mark
overflow
protect
red
relief
river
riverbank
rubber
safety
security
sign
stamp
sticker
symbol
warn
water
weather
white