a large body of salt water
ocean
water that has little or no salt
fresh water
the changing of a liquid into a gas
evaporation
water in the form of an invisible, odorless gas
water vapor
the changing of a gas into a liquid
condensation
droplets of water that form in the atmosphere and fall to the ground
precipitation
the continuous movement of water between Earth's surface and the air
water cycle
a human-made lake that is used to store water
reservoir
a barrier that prevents the normal flow of water
dam
water beneath Earth's surface
groundwater
an underground layer of rock that can hold water
aquifer
the area where water drains into a river
watershed
the overflow of water from the banks of a body of water onto the land
flood
a long period of dry weather
drought
to make dirty or unclean
pollute
making something usable again
reclamation
a pathway built by people to move water long distances
aqueduct
save something to be sure there is enough
conserve